Theories of learning: Traditional perspectives/contemporary developments 0534006981

Table of contents :
PREFACE
INTRODUCTION

The Hows and Whys of Learning: Some Key Issues
On Theories and Theorists

PART ONE: THE HISTORY OF LEARNING THEORY

1 BASIC PRINCIPLES AND BACKGROUND OF PAVLOVIAN CONDITIONING
2 AMERICAN APPROACHES TO CONTIGUITY CONDITIONING: WATSON AND GUTHRIE
3 LEARNING THROUGH REINFORCEMENT: THORNDIKE AND HULL
4 SKINNER: REINFORCEMENT OR OPERANT CONDITIONING
5 COGNITIVE ALTERNATIVES
6 THE PAYOFF: APPLICATIONS OF SELECTED LEARNING THEORIES
7 MULTIFACTOR AND ECLECTIC APPROACHES

PART TWO: MODERN CONTENDERS: AN INTRODUCTION TO THE STATE OF THE ART

8 ADVANCES IN CLASSICAL CONDITIONING: SOVIET AND AMERICAN
9 RECENT DEVELOPMENTS IN THE STUDY OF REINFORCEMENT-RELATED LEARNING
10 APPLICATIONS OF OPERANT LEARNING PRINCIPLES TO THE REAL WORLD
11 MODERN THEORIES WITH A COGNITIVE EMPHASIS
12 THE BIOLOGICAL BOUNDARIES OF LEARNING

GLOSSARY
REFERENCES
INDEX

Citation preview

Theories of Learning:

Traditional Perspectives/Contemporary Developments.

Lela nd C. Swenson Loyola Marymou n t University =-

Wadsworth Publishing Company Belmont, California A Division of Wadsworth, Inc.

Psychology Editor: Kenneth King Production Editor: Carolyn Tanner Designer: Robert Hu Copy Editor: Victoria Nelson Technical Illustrator: Evanell Towne

ACKNOWLEDGMENTS Excerpts in Chapters 4 and 9 reprinted with permission of Macmillan Publishing Company, Inc., from Science and Human Behavior by B. F. Skinner. Copyright© 1953 by Macmillan Publishing Company, Inc. Excerpt s in Chapter 5 from E. M. Standing, Maria Montessori: Her Life and Work (Fresno: Aca­ demic Press Guild, 1959). Reprinted by permission. Excerpt s in Chapter 9 from Werner K. Honig, Operant Behavior: Areas of Research and Applica­

tion, © 1966, pp. 426-427. Reprinted by permission of Prentice-Hall, Inc., Englewood Cliffs, New Jersey.

© 1 980 by Wadsworth, Inc . All rights reserved. No part of this book may be rep roduced, stored in a retrieval system, or transcribed, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, withou t the prior w ritten permission of the publisher, Wadsworth P ublish­ ing Company, Belmont, California 94002, a division of Wadsworth, Inc. Printed in the United States of America 1 2 3 4 5 6 7 8 9 1�4 83 82 81 80 Library of Congress Cataloging in Publication Data Swenson, Leland. Theories of learning. Includes bibliographical references and indexes . 1 . Leaming, Psychology of. 2. Conditioned response . I . Title. 79-15139 1 53 . 1'5 BF3 18.S93 ISBN 0-534-00698-1

Table of Contents

\

Table of Contents PREFACE

Xlll

INTRODUCTION

3

The Hows and Whys of Lea rning: Som e Key Iss u es

4

On Theories and Theorists

7

PART ONE 1

THE HISTORY OF LEARNING THEORY

11

BASIC PRINCIPLES AND BACKGROUND OF p AVLOVIAN CONDITIONING

Ivan Petrovich Pavlov (1849-1936)

13 13

Classical Conditioning

14

Reflexes: The Physiological Basis for Classical Conditioning

16

Inhibition

18

The Stages of Conditioning and Extinction

20

Discrimination and Generalization

21

The Basic Types of Conditioning

22

Effects of Combinations of Excitatory and Inhibitory Stimuli

26

From Laboratory to Real Life

27

Conditioning and Abnormal Behavior

28

Pavlov's Positions on Major Issues

29

Chapter Perspective

30

2

AMERICAN APPROACHES TO C ONTIGUITY CONDITIONING: 34

WATSON AND GUTHRIE

34

Jo hn B roadu s Wa tson (1878-1958) Behavior as the Yardstick of Leaming

35

How Do We Learn? Watson's Answer

36

A Contiguity Explanation of the Effects of Apparent Reinforcement

37

The Case of "Little Albert"

37

Watson's Positions on Major Issues

38

Perspective

39

Edwin

R.

Gu thrie (1886-1959)

40

A Single Law of Leaming

40

Applications

43

Guthrie's Positions on Major Issues

45

Perspective

46

Optional Section : Willia m Kaye Estes (1919-

)

Chap ter Perspective 3

LEARNING THROUGH REINFORCEMENT: THORNDIKE AND H ULL

Edward L. Thorndike (1874-1949)

47 49 50 52

How Leaming Occurs: Thorndike's Early Theory

53

How Leaming Occurs: Thorndike's Later Revisions

55

Applications

56

Thorndike's Positions on Major Issues

57

Perspective

58

v111

Conten ts

58

Clark L. Hu ll (1884-1952) The Structure of Hull's Theory

59

Major Intervening Variables

60

Changes in the Theory from 1943 to 1952

67

Spence's Contribution to H ullian Theory

70

Hull's Positions on Major Issues

72

Perspective

72

Chap ter Perspective

73

4

75

SKINNER: REINFORCEMENT OR OPERANT CONDITIONING

B u rrhus Frederic Skin n er (1904-

)

Skinner's Approach to the Contiguity/Reinforcement Issue

77

Skinner and the Generalizability of the Laws of Leaming

79

The Skinner Box

80

Major Principles

81

Schedules of Reinforcement: Skinner's Most Important Contribution

85

Skinner's Extension .of His Laws to Complex Human Behavior

94

Skinner's Positions on Major Issues

97

Chap ter Perspective 5

75

COGNITIVE ALTERNATIVES

Edward Cha ce Tolma n (1886-1959)

98 101 103

Major Principles

104

Experimental Evidence Supporting the Major Principles

105

Tolman's Positions on Major Issues

109

Perspective

110

Gestalt Learning Theory : Wertheimer, Kohler, Kaffka , a nd Lewin

111

Origins of the Gestalt Movement

111

The Laws of Organization for Leaming, Memory, and Perception

114

Kurt Lewin's Version of Gestalt Theory

117

Gestalt Positions on Major Issues

119

Perspective and Applications

120

Contents

ix

121

Maria Montessori: A Biocognitive Sensory-Motor Theory

Origins of the Montessori Method

121

Montessori's Maturational Model of Children's Leaming

121

The Didactic Materials

123

Research on the Effectiveness of the Montessori Method

125

Montessori's Positions on Major Issues

126

Perspective

127

Norbert Wiener's Cybernetics: A Possible Gateway to Tomorrow

128

Machine and Computer Analogs of Leaming

129

Wiener's Positions on Major Issues and Perspective

130

Chapter Perspective

131

6

133

THE PAYOFF: APPLICATIONS OF SELECTED LEARNING THEORIES

Extension of Pavlovian Principles to the Process of Childbirth

134

The Read Method

136

The Lamaze Method

137

Applications of Classical Conditioning in Clinical Psychology

Systematic Desensitization

138 138

Applications of Skinner's Reinforcement Theory

143

Teaching Machines and Programmed Leaming

144

The College Classroom

147

Gestalt Principles Applied

149

Chapter Perspective

152

7

154

MULTIFACTOR AND ECLECTIC APPROACHES

Two-Factor Principles, Neo-Hullian Approaches Neal E. Miller (1909-

)

and John Dollard (1900-

155

)

155

Primary Principles of the Miller and Dollard Theory

156

Dollard's and Miller's Positions on Major Issues

165

Perspective

166

x

Conten ts

0. Hobart Mowrer (1907-

166

)

The Two-Factor Theories

166

Mowrer's Positions on Major Issues

170

Perspective

171

Functionalism: A Position for All Reasons

171

The Transfer of Training Problem in Verbal Leaming

172

Functionalist Positions on Major Issues

176

Harry F. Harlow (1905-

)

177

Perspective

178

Chapter Perspective

179

PART ONE SUMMARY

181

Contiguity Theorists

181

Reinforcement Theorists

182

Cognitive Theorists

183

Multifactor and Eclectic Theorists

184

Part Perspective

184

PART TWO MODERN CONTENDERS: AN INTRODUCTION TO THE STATE OF THE ART

187

8

ADVANCES IN CLASSICAL CONDITIONING: SOVIET AND AMERICAN

190

Soviet Psychology since Pavlov: Advances in Expanding the Scope of the Pavlovian Paradigm

191

Interoceptive Conditioning

193

Semantic and Verbal Conditioning

195

American Contributions to Classical Conditioning Theory

199

Pavlovian Phenomena Discovered by American Researchers

200

Reinterpretations of Classical Conditioning Mechanisms

205

Contents

Recent Innovations in the Application of the Pavlovian Paradigm to Clinical Psychology

216

Applications in Sex Therapy

223

Male Dysfunctions

224

Female Dysfunctions

225

Chapter Perspective 9

xi

226

RECENT DEVELOPMENTS IN THE STUDY OF REINFORCEMENT-RELATED LEARNING

Contributions to Reinforcement Theory in the Neo-Hullian Tradition

229 230

How Exposure to Unrewarding Experiences Influences the Effects of Reward

230

How Changing the Amount or Kind of Reward Influences Behavior

233

Contributions to Reinforcement Theory in the Neo-Skinnerian Tradition

236

Contributions of Neo-Skinnerians Emphasizing Positive Reinforcement

237

The Control of Behavior by Aversive Consequences

247

Social Leaming Theory

259

Chapter Perspective 10

264

APPLICATIONS OF OPERANT LEARNING PRINCIPLES TO THE REAL \tVORLD

General Principles of Contingency Management

268 268

Specification

268

Observation

274

Consequation

278

Optional Section: Selected Examples of Operant Applications

281

An Introductory Smorgasbord

281

Applications of Contigency Management to the Schoolroom

287

PSI: An Application for College Classrooms

291

Clinical Applications

293

Biofeedback

295

Chapter Perspective

301

Con tents

.rzz

Appendix to Chapter 10: Timing Tape Techniques for Use in Observing Behaviors

303

11

304

MODERN THEORIES WITH A COGNITIVE EMPHASIS

Concept-Learning Theories and the Concept-Growth Model of Eli Saltz

306

Concepts as the Basic Unit of Leaming

306

The Common Response Model of Concept Leaming and Saltz' s Critique

309

Types of Concepts and Strategies for Assigning Attribution to Concepts

312

The Concept Growth Model

313

Saltz's Version of the Interference Theory of rorgetting

315

Integration of the Elements of a Concept

316

Perspective

318

Noam Chomsky: A Cognitive-Naturalist Model of Language Learning

318

How Meaning Is Translated into Speech and Conscious Thought

319

Perspective

323

Jean Piaget: A Cognitive-Maturational Theory

324

Outline of the Cognitive Theory and Basic Principles

324

The Developmental System Related to Leaming

328

Perspective

334

Infonnation-Processing Approaches to Learning and Memory

336

The Stages of Leaming

337

Perspective

349

Chapter Perspective

349

12

THE BIOLOGICAL BOUNDARIES OF LEARNING

The Neuropsychology of Learning and Mernory

A Brief History of Neurophysiological Approaches to Leaming and Memory

352 354

354

Pribram' s Theory of Learning and Memory: Holograms in t he Head

367

Attention and Habituation

367

The Processing of Information

372

Con ten ts

xm

Leaming on the Neuronal Level

373

Perspective

377

The Biologically Detennined Boundaries of Learning

377

Contributions by Ethology and Comparative Psychology to Understanding Learning

377

Perspective

390

Chapter Perspective

391

Appendix to Chapter 12: The Physical Hologram

392

PART Two SUMMARY

395

GLOSSARY

402

REFERENCES

430

INDEX

455

Preface

The completion of most major projects in our lives have a history and this learning textbook is no exception. When I began teaching courses in learning psychology at Occidental College in Los Angeles I was faced with a problem. I was unable to find a single text that covered most of the topics I thought essential to an adequate exposure to this very important area of psychology. My response was to order a variety of supplemental books. This response created a new problem-that of students being reluctant to buy and read multiple texts. This forced me to begin writing and distributing short supplemental handouts. Later in my current teaching position at Loyola Marymount University I continued to write and revise these supplements until I had finally replaced all but one of the supplementary texts. By 1975 my supplements had developed into the rough draft of a complete learning text manuscript. Discovering this, various pub­ lishers' representatives suggested submitting this manuscript to their publish­ ing houses. The initial feedback was sufficiently encouraging to goad me into serious writing and revising. My goals were to create a text that combined a historical perspective on the development of major learning theories, a sound exposure to major principles of learning, and information about how learning principles and theories were being applied in the real world, with student-oriented writing and a multitude of examples. I wanted to expose students to both animal and human research and to the process by which early discoveries about learning evolved into the issues and principles of interest to today's psychologists and educators. I planned my language and examples to be interesting and understandable to students, hopefully without oversimplification. Most of all I wrote to communi­ cate my excitement about the great progress being made in understanding learning and how it affects all our Iives. This text was designed to provide a solid background in the psychology of learning for students with a wide range of academic and career objectives. To make this complex subject area understandable to students with diverse inter-

xvi

Preface

ests, I incorporated many learning aids including: introductory and perspective sections for all chapters and parts of the text, mini-summaries of major points, lists of key terms, a glossary of such key terms, and comparisons of each major theory on six key poin ts. All of these features were developed over several years of class testing and interactions with the Wadsworth editorial and peer-review personnel. The organization of this text reflects ten years of my experiences in present­ ing the essential aspects of learning psychology. The first half introduces the major principles incorporated within the great theories of learning, arranged in rough chronological order. The second half builds on these theories and princi­ ples by showing how current research has forced re-evaluation of many of their major assumptions. Approaches covered in the second half of the text are ar­ ranged in the same order as the earlier versions of these approaches to facilitate comparisons and a sense of continuity. A major content innovation in this text is thorough coverage of modem cognitive theories, including the information pro­ cessing paradigm. Both parts of the text provide extensive review of applica­ tions related to basic points of theory and principle to further aid the student in mastering the material. Finally, any writing project of this scope is rarely a solo effort. I would like to gratefully acknowledge the detailed reviews provided by the following review­ ers: Kenneth Basilio, Salem State College; William Hellix, San Diego State Col­ lege; Peter Holland, University of Pittsburgh; Jerry Ison, Missouri Western State College; and Susan Mineka, University of Wisconsin. Additionally, I would like to thank Laurel Bartlett for her inspiration and assistance during the formative stages of this manuscript, Beverly Frazier, Nancy Clark, Patrice Miles, Sharon Geraci, and the Loyola Marymount University faculty secretaries for their help in typing, editing, and evaluating the developing text, the Wadsworth people (especially Ken King, the psychology editor) for their advice and assistance, and my students for continuing support and feedback. This book would never have been completed without the enthusiasm of my students: I hope you con1e to share their (and my) excitement with this text and the field of learning psychology.

Theories of Learning

Introduction

Somewhere, somebody has j ust discovered that he really likes j azz . This seems strange to him, b ecause he has always hated j azz. By coincidence, he is fi ercely in love with someone who loves j azz and spends wee kends listening to i t . Somewhere else , a student sitting at her d esk has a sudden flash o f i nsight about why p sychology departments require their maj ors (who are enrolled in psychology to un derstand people) to take courses i n statistics and what the relationship is between statistics and understanding peopl e . And finally, a teacher i s giving elementary school p upils checkmarks for desirable behaviors . The children have been told that they will be able to h ave various treats and p rivileges at a later t ime based on the number of checks they receive, and the teacher notes with satisfaction that thei r behav i or is getting better d ay by d ay . . . All these events are examples of the process (or processes) that we call learning. Leaming is the most important process by which we manage to change, adapt, and become ( hopefully) more competen t over the years . The study of how this p rocess occurs is a special and important responsibility of the serious student of p sychology. Of all the subdivisions of psychology , none has seen s uch widespread application, i n so many places and for so many purposes, as the p sychology of learning . The p ri nciples derived fro m the w ork of B . F. Skinner have led to the p owerful tech nology of token economies, a techn i q ue which is extensively applied i n sch o ols, hospitals, prisons, and therapy settings . Parts of Piaget's theory have become comm on practice i n mo dem lower- grade classrooms . In many environments and i n many ways, the res ults of research by learning theorists on how we learn are changin g lives . Ironically, nowhere else in p sycholo gy have the p ositions of maj or theoris ts been so far apart and the arguments so heated as in d ebates among learning theorists-especially b e tw een the strict behaviorists and the cognitive humanists. Behaviorists claim that our behaviors are caused by events in o ur environments ( stimuli), and co gnitive human ists assert that we are capable of free choices; there seems little room for com prom ise between the two . The arguments are heated and the stakes are h ig h . In the application of learning pri nciples, psychologists claim to have the technology not only to aid learning and change individual behav i ors but, ultimately , through univers al application, to mold the type of w orld in which we live . Wi th stakes such as these , it is important for anyone involved in the study of p sychology who plans

4

Introduction

to "work with p eople" to become familiar with the maj or learn ing theories and learning principles . To un derstand the assumptions, vi tal fin din gs, and laws of learn ing of each theoretieal position, moreover, you must be familiar not only w i th current maj or theories b ut also wi th their h is torical roots . The first half of this book provi des j us t s uch a h istorical foun da tion . Speculation about what is learned and how we learn i t has a long h is tory . Aristotle, the Greek p h ilosopher, s uggested that learning occurred b ecause of the a ssociations in the s ame times, or spaces, of things and idea s . For example : If a professor always p refaced important p oints by cleari n g her thro at, you would tend to get ready to take notes whenever she showed this behavior. This as­ sociationist or contiguity explanation of learn ing reapp ears in the writings of s uch eighteenth- and n ineteenth-century B ri tish p h ilosophers as J ames Mill and John Stuart Mill ( in Horton and Turnage, 1 976) and contin ues to be influen tial via the principles of classical c onditioning developed by Pavlov in Russia . In addition to assuming that learning occurs thro ugh the contigui ty of sensations, the association ists assumed that the mind of the newborn human was a blank slate ( tabula rasa) upon which experience wrote . O pposed to the associati onists' n u rture or environmental bias were the views of s uch p h ilosophers as Descartes and Kant, who believed tha t the content and operations of the mind were largely innately determ ined . As you will see, this nature bias is still important, if in a weaker form , in some of the theories t o be presented to you . The p urpose of this extremely brief summary of the p hilosophical back­ ground of investigations about learning has been to i n troduce some of the issues that divide learning p sychologists. Let us now outline these issues . This o utline will, i n tum, provide us wi th a system for classifying the theori es and theorists discussed in this book . The H ows and Whys o f Leaming: S ome K e y I ss ues

The first maj or issue is the con tent of learn i n g. Most of the philosophers who were concerned about learning assumed that the s ubs tance of what was learned was ideas or mental s tructu res. Ideas are also called cognitions, and psycholo­ gists who believe that ideas are un its- of learn ing are called cognitive learning theorists . The s tuden t mentioned at the beginn in g of the chapter who had a s udden insight into the relationship between s tatistics and understand ing p eople illustrated cognitive learn i n g . In o pposition to this viewpoint are the connectionis t theorists, who believe that the essen tial unit of what is learned is a new connection between an environmen tal event ( s timulus) and either another s timulus or a res ponse . Since most connect ionists rej ect the idea of examining ideas in favor of observing overt (that is, observable) behaviors, an activi ty that is assumed to b e more objective and scientific, they are also often labeled behav iorists . A second maj or issue is how the elements lea rned are connected . Aristotle and the British associationist philosophers previously mentioned a ss umed that the contiguity, the p roximity or close associa tion, of the elem ents was sufficient . The example w e s a w of the pairi n g of j azz with a distinctly pleasant stimulus ( in th is case, a girlfriend) was able to b ring about p osi tive feelings toward s j azz. Theories of learning based on th is assu mpt ion are thus labeled con tiguity theo-

Introdu ction

5

ries i n this book . The opp osing view assumes that the pleasan t or unpleasant (or d rive- reducing or p ainful) consequences of behavior determi ne whether some­ thing will b e learned , as when a teacher, for example, is able to i ncrease the desirable behavior of children through reward s . These theories are related to the p hilosophy of he donism, which concerns itself with the effects of pain and pleasure on human behavior. Theories of learn ing which focus on the conse­ q uences of behavior are labeled rein forcement theories in this book. Here rein­ forcement is regarded a s roughly like reward , b ut withou t i ts subj ective emo­ tional connotations . The third maj or issue d ividing learn ing theorists i s the issue o f nature ver­ sus nurture: that is, to what extent are innate factors res ponsible for learning? Behav iorist theorists retain the nurture (environmental) b i a s of the early as­ sociationist p hilo sophers, while theorists with closer ties to b iology tend to favor including innate or nature factors i n their theories . John Watson, the first self­ identified behaviorist, believed in the tabula rasa or blank state concept so strongly that he thought all human d ifferences i n abili ty and personality traits were the res ult of learning. Recently, the behavioristic n u rture bias has been challenged by theorists who think we may inherit an i nborn predisposition to learn some things more easily than others, s uch as fears of snakes or spiders . To prepare you for the material to be covered in th is book, Table 1. 1 s hows you where each of the maj or theorists stands on these three central issues . It m ay be helpful for you to review Table 1.1 as you finish studying each of the two p arts of this book . The opening chapters of each part of the book cover the contigui ty ­ connectionists followed b y the reinforcement connectionis ts, the cognitivists, theories using many b iological concepts, and fin ally two- factor ( a theoretical approach we will examine in greater detail) , multifactor, and eclectic* theorie s . Both p arts of the b o o k then conclu de with summary and integrative material . In ad dition to the three great issues j ust d iscusse d , some other important points o f con troversy bear mention ing. One of these is the q uestion of the legi timacy of generalizin g pri nciples d iscovered through research on animals to human learning . Skinner has d eveloped teach ing machines for u se with ch il­ dren based on the same p rinciples used in b uilding "Skinner b oxes" for p i ­ geon s . The assumpt ion that the basic laws of learning are the s a m e for rats, pigeons, and humans has been a central a ssumption of most behaviorist s . We will d iscuss the relevance of this assumption to behavioristic models o f learning as well a s reviewing attacks on i t, both b y cognitive theorists who feel that human learning is q ualitatively d ifferent from animal learning, and by biolog­ ically oriented theorists w ho feel that the forces of evolut ion have led to some differences in how the laws of learning apply to d ifferent species . Another issu e that d ivides theorists is that of the continu i ty or d iscontinuity of the basic (earning process . Most behaviorists (Guthrie is a noted exception) believe that the learning of connections is a gradual and continuous process, * Eclectic means tolerant and willing to b orrow ideas from a range o f opposing v i ewpoints . For example, some two-factor theorists have proposed that some kind s of learning occur through the act i ons of contiguity factors while other kinds of learni ng occu r through re inforcement factors .

0-.

Table I . 1 Theorists and Issu es The Wha t of Lea rning Con nectionist (5-R a nd/or 5-5 Bo nds Lea rned )

-

--c

...,..

Cognitivis t (Ideas or Men tal S truct u res Lea rned)

Neutra l

0 :::a... ::::: ri ...,..

Watson Guthrie Skin ner Miller an d Dollard Thorn dike

Pavlov early Mowrer most neo-Skinn erians Hull an d Spence Garcia

Tol man late Mowrer Montesorri Saltz Luria (neo-Pavlovian) Band u ra Pribram Seil gman

gestalt theorists Chomsky Piaget

The How of Learning Reinforcemen t as the Mech a n is m

Neutral

Con tigu ity as the lv1ech anism Pavlov Watson Gu thrie

Spence

Thorndike Miller and Dollard

Hull Skinner neo-Skin nerian s

Involvemen t of In nate Factors Nu rt u re Bias Watson Gu thrie

Pavlov Thorndike Hull and Spence Skin n er and neo-Skinnerians Tolman Sal tz fu nctionalists

Neutral Pribram

Na t u re Bias ges tal t theorists Montessori Cho msky 'Piaget Selig man and Garcia

ethologists

Th is table shows the relative posi tions taken by the theorists pre sented in this book on three major issues. Theorists not l isted und er a particul ar issue pre sen t no clear posit ion . S = sti mulus, R = response.

0

-

Introdu ction

7

with the strength of the connection gradually i ncreasing as the n umber of suc­ cessful trials i ncreases . G uthrie and most cognitive theorists believe that a con­ nection or cognit ion or insight can app ear suddenly and a t full strength at one p articular momen t . Another importan t issue which h as led to many heated d iscussions at psy­ chological conventions is the issue of determi n ism versus free will . The extreme behaviorists see our behav ior as "caused" by even ts in our p as t and p resent environments, b u t most cognitive theoris ts see us as be ing able to make real choices about our behav ior. The behav iorists accuse the human istic-co gnitive theorists of be ing illogical and rom an tic and the cognitive humanist psycholo­ g ists call the behaviorists manipulative and blind to t he real meaning of what it is to be a human being . These differences among p sychologists h ave more rele­ vance than simply i nciting i n teresting cocktail p arty conversation s . They deter­ mine w h at p ri nciples get applied, by whom, and for w h at p urposes . Because one factor determi n in g the infl uence of a given theoretical appro ach is the extent to which its pri nciples can be translated into useful applications, t h is text will follow up the p urely theoretical m aterial in t he chapters w i th suggestions for appl ication and examples of applications . This m aterial on ap­ plications should help you to g a in a broader appreciation of the impact of the learn ing theories and a better understanding of the theories behind the application s . On Theories .and The orists

You w ill discover that p a rt of t he difference among v i ew points is a matter of defining the s ame things i n different ways . The s ame facts may b e i n terpreted by d ifferent theorists i n different ways . Theorists m ay also use the s ame term b ut define it d ifferently . Just w hat does t he term " reinforcement" mean? P avlov defines it as following a learned cue (or stim ulus) by a cue to which the organism is innately pro gram me d to resp on d . Skinner, on the other h and, defines it as whatever increases the pro b ab ility of a reoccu rrence of the response which oc­ curred j ust before the reinforcemen t event . What does the term " unlearned drive" mean? Tolman s uggests that exploration is an example of such a basic nee d , w hile Watson limi ts basic n eeds to b i ological necessities s uch as foo d , water, and sex . Theorists also interpret the s am e obj ective even t in different w ays . A rat can learn to alternate between g o ing left and going right in a T- shaped simple m aze . The cogn itive theorists would m ainta in that the rat h as a concept abou t the relation s h ip of trials and d i rections to tum . The b ehaviorists retort that the rat has lear ned a series of internal stimulus-respo nse connections . And so it goes . . . Another source of difference among learning t heorists is related to t he per­ sonalities and prej u d ices of the maj or theorists and the ir willi ngness to defend their t heories . Yo u will fin d that theories are more l ikely to cease being taken seriously as a res ult of the ir m aj or advocate's death than as the res ult of dev astat­ ing experiments conducted by the ir foes . In general, as long as a t heorist re­ m ains i nterested i n his theory, he tends to change it to h andle potentially

8

Introdu ction

dangero us data rather than swi tching to embrace the theory of a rival . As theo­ ries are mo dified to p revent d i rect contradiction by d ata that does not fi t the theorist's original concept, they tend to lose the special clear insight of their developers and beco me d iffu se and complex. The result of this process is that theories tend to become more and more like one ano ther while retain ing their specialized systems languages, or j argons . I f s o much depends on definition and p ersonal i ty , why study learning theo­ ries at all, and especially why s tudy obsolete theories? Part of the answer is that the maj or theories developed before 1955 dealt wi th the same maj or issu es that divide the modern theorists to be presented in Part 2 of t his b oo k . For another, the early theories p rovide clear and consistent views of different asp ects of learn ing and illuminate and clarify the maj or issues . Th is illumination of maj or issues is a very valuable tool in tryin g to understand the same issues concealed wi thin the more diffuse framework of modem positions . A sound knowledge of the basic aspects of early psychological theories of learn ing will help to provide a p erspective for the s tudy of current theories and a unifyi ng base on which to b uild knowledge about current trends and p ri nciples . In ad dition, the early theories p rovide a logical place to begi n introducing maj or pri nciples, since these principles were developed wi thin these organ ized theoretical systems . Theories are essentially tools to help us to understand complex events . They are simplified versions of reality which, if well d esigned, c an predict what will happen in reality . Theories are thus models of real i ty, j u s t like mos t model airplanes are designed to represent real a irplanes . If a model airplane is eno u gh like the real airplane i t represents, some of i ts "behaviors, " s uch as gliding characteristics, will p redict similar actions in the real a irplane. If a theory is a close enough match to the real world, predict ions generated fro m that theory will p redict real behavior of real organisms . M ost of the theories presented in Part 1 of this book are co mprehensive theories that attempt to explain a wide range of behaviors . Many of the theories presented in Part 2 of this text, however, are much more limited in scope . Chomsky' s theory o f language learn ing is a n example . Such miniature theories are often called models rather than theories . Use of the term "model" does not make s uch a miniature theory any less a theory, and the comments about the uses of theories also apply fully to mo dels. The trend towards models abo ut limited kinds of learning reflects the inc reased knowledge about learning which has resul ted fro m continuing research . As our to tal knowledge increases, so does the difficulty of fi tting all the different kin ds of findings into one co m­ prehensive theory. Theories have helped to pro mo te immense creativi ty in re­ search by forcing their creators to defend their own work an d to d iscredit rival theories . The pro gress of psychologis ts tryin g to unders tand learn ing has often been slow, and if theorists were not motiva ted to defend and a ttack theories, much less important and useful research would have been done than is actually the case . The d ata collected a s a result o f this intense process may eventually lead to one unitheory of learn ing. This hypothetical un itheory would be the "one" theory of learning, j ust as chemists have one theory of the relationships of the

Introdu ction

9

p hysical elements i n the p eriod ic table . We are a long w ay from that goal, however. As our science m atures, t he role of clearly defined and d ifferentiated theories is d im inishing. Leaming is now generally conceded to be much more complex than the e arly theorists thought. Increasingly, psychologists are b eco m­ ing eclectic and are borrowing from m any viewpoints . As you go through this text, compare the theories of the first and sec o nd p arts and note this process of increasing complexity . Some prominent theorists ( such as Skinner) h ave ar­ gued for simply collecting empirical facts and avoiding premature attempts to explai n underlyi n g variables . This does not mean, however, t hat Skinner is unwilling to discuss t heoretical issues. The esse n tial assumptions about man and learning that underlie the posi­ tion s of the connectionis t theoris ts as com p ared to the cogn itive theorists are worlds apart, and these differences lead to m aj or differences i n their respective prescrip tions for action . The d iffering assu m pt ions influenced the basic and comprehensive l aws that h ave been developed by each theorist; these l aws i n turn determined the applications suggested for use in the real world ( the world lying two feet o utside of the borders of all coll eges and un iversities) . To under­ stand these all - important assumptions, it is helpful to refer b ack to their h istori­ c al roo ts . Theories and theorists are not independen t of historical influences . Because the historical context w as so i mportant in influencing the work of maj or theorists, a short biographical statement about e ac h of these theorists is presented in Part 1 of this book. This background should a i d you in understand­ ing why these theorists developed the assump tions that t hey d id . Most of the trends i nitiated by the maj or early theorists are explored further i n Part 2 . Be­ cause P art 2 for the most p art develops existing trends coverin g many con­ tributors and is foc u sed o n n ew princ iples rather than t heories, such biograph i ­ cal information i s not i ncluded in t he secon d p art. Key Terms associationist

contiguity

nurture

behaviorist

eclectic

reinforcement

classical conditioning

hedonism

tabula rasa

cognition

innate

two-factor theory

cognitive humanist

insight

unitheory

cognitive learning

instrumental

connectionist

nature

The History of Learning Theory Introduction

T h e first t h e ori e s we w i l l l o o k at i n P a rt 1 a re the c o n n ecti o n ist t h e o r i e s, because t h e m o d e r n era of t h e st u d y of l earn i n g b e g a n w i t h Pav l ov's st u d y i n Ru ssi a o f c o n t i g u i ty con d i t i o n i n g and T h o r n d i k e's stu d y i n A m erica of re i nf orc e m en t(reward )-d e p e n d e n t c o n d i t i on i n g . Watson a n d G u t hrie were t h e fi rst t o d eve l o p A m erican t h e ori es o f c o n ­ t i g u ity co n d i t i o n i n g . Watso n n o t o n l y bro u g ht t h e t e r m "be h av i orist" i n t o t h e la n g u ag e of psy c h o l ogy b u t, d uri n g h is l ast years i n t h e acad e m i c w orl d , p o p u l a ri zed Pav l ov's f i n d i n gs as we l l . T h e part beg i n s w i t h t h e cont i g u i ty t h e o r i es; Ch a pter 1 covers Pav l ov, a n d Ch a pter 2 i n t ro d u ces Watson a n d G u t h ri e. The re i n f orce m ent-co n n e ct i on ist t h e o­ r i e s a re a l so prese n ted i n h i st ori c a l sequ ence, beg i n n i n g w i t h T h orn d i ke a n d H u l l i n Ch apter 3 a n d f i n is h i n g w i t h S k i n n er i n Ch a pter 4. A l l t hese t he ories are d is t i n g u i s h e d by a c o m m o n e m p h asis o n a n i m a l l e arn i n g a s a n a n a l o g for h u m a n l e arnin g; by a fo c u s o n t he c u es or sti m u l i present i n t he l earn i n g s i t u at i on rat her t h a n o n i n n er causes of b e h av i o r; a n d by a m e c han i st i c fl avor to t h e i r l aws of l e a r n i n g. Both types of con n e c t i o n ist a p proa c he s h ave l ed t o a w i d e ra n g e of p owerf u l and w i d e l y u s ed a pp l i c at i o n s, so m e of w h i c h are rev i ewed i n C h a pter 6. S o m e i n terest i n g c o m p ari so n s m ay be m ad e i n i ti a l l y between Pav l ov o n one h a n d a n d Watson a n d G u t hr i e o n t h e o t h er. Pav l ov's work d eve l o ped fro m h i s tra i n i n g a s a p hysi o l og ist, a n d he i s c o n seq u e n t l y m ore wi l l i n g t h a n h i s A m eri c a n c o u n terp arts t o i n c orporate b i o l o g i c a l vari a b l es i n h is t he ory, i nc l u d i n g assi g n i n g a l i m i te d i n herited c o m po n e n t t o l e arn i n g ab i l i ty. H e also d eve l o ped extre m e l y i n tri c ate pri n c i p l es d e­ rived f r o m a m u l t i t u d e of caref u l l y c o n tro l l ed e x peri m e n ts by h i ms e l f a n d h i s researc h asso c i ates . Ne i t her Watson n or G u t hri e h a d ac cess to a n yt h i n g a p proa c h i n g Pav l ov's reso u rces for resea rc h , a n d b o t h t h e ir fairly s i m p l e t he ori e s ref l e c t t he i r l esser re­ searc h prod u c t i v i ty . W h i l e Pav l ov saw h i m s elf as a c o n t i n u a t i o n of a stro n g trad i t i o n of o bje c t i ve s c i e n c e , Watson a n d G u t hr i e saw t h e m s e l ves as rev o l t i n g agai n st t h e "no n sc i e n t i fi c" u s e of m e n ta l d ata g a t hered fro m verb a l re p orts a b o u t m e n ta l eve nts by tra i n e d su bje cts . I n their reje c t i o n o f t h i s m e n ta l i s m and their d esire t o m a ke psyc h o l o g y a n "hon est s c i en c e" ( Pav l ov o nce c a l l ed psy c h o l ogy "t h e h o pe of a s c i ­ ence"), t h ey e m braced t h e o p posite e xtre m e of rad i c al b e h av i or i s m ( t he be l i ef t h at o n l y b e h av i or c o u l d be u sed as d ata) . A l t ho u g h Pav l ov's pri n c i p l e s a n d term i n o l o g y st i l l e x ert c o n si d erab l e i n fl u e n c e tod ay, Watson a nd G u t hrie are pri m ari l y of i m p or­ tance because of t he i r tre m e n d o u s i nf l u e n ce i n m o v i n g A m eri c a n p syc h o l og y i n t h e

12

Th e History of L ea rn ing Theory

d i rect i o n of b e h av i o r i s m . By t h e 1 930s , t h e b e h av i o ri s t i c ba n n er was s l i p p i n g i n to t h e h a n d s of t h e re i n f o rc e m e nt-co n n e ct i o n ists . A l t ho u g h t h e d u ra t i o n of t h e d o m i n a n c e of c o n t i g u i ty t he o r i sts i n t h e Un i ted States was r e l at i ve l y s h ort, re i nf o r c e m e nt-co n n e ct i o n ist t he o r i es d ate bac k to the p u b­ l i c at i o n i n 1898 of T h o r n d i ke's d issertati on o n c ats ' esc ape st rate g i es f ro m p u zzle boxes. Th e n , i n t h e 1 940s a nd earl y 1 950s, H u l l ( a n d h i s fo l l o wer and m od i f i e r Spence) p rod u ced t he m o st e l a b o rate a n d spe c i f i c ( i n te r m s of p red i ct i o n s) t he o r i es d ev e l o ped to t h at t i m e w i t h i n A m er i c a n psyc h o l o g y . Fi n al l y, Sk i n n e r has c h a l l en g ed n o n ­ b e h av i or ist i c v i ews o f l e a r n i n g f ro m h i s e a r l y wo r k i n t he 1 930s to t h e presen t . H e i s o n e o f t h e most d o m i n a n t a n d a c t i v e ad v o c ates w i t h i n a n y b r a n c h of psyc h o l o g y . T h es e t h e o r i es, w i t h t he i r e m p h asis o n b e h av i o r a s d eter m i n ed by t he rei nfor c i n g c o n s e q u e n c es of t he e n v i ron m en t , were ( a n d , i n S k i n n er's cas e , a r e) w i d e l y accepted a n d a p p l i ed a n d j u st as w i d e l y attac k ed as r e p res e n t i n g a n aff r o n t to t h e d i g n i ty o f m a n . In v i e w of t h e be h av i o rists' g o a l s o f p red i ct i n g a n d c o n t ro l l i n g h u m a n b e h av i o r , so m e o f t h e a n x i et i es m o t i v at i n g t h ose attac kers m i g h t be just i f i ed i f o n e i s o p posed to p red i c t i o n and c o n t ro l! C h apter 5 e x p l ores t he t heo r i es of so m e of t h e attac kers of b e h av i o r i s m . T h i s c h apter ex a m i n es cog n i t ive altern at i v es t o c o n d i t i o n i n g t h e o r i es; o n e is A m e r i c a n a n d t h e o t h ers a r e Eu ro pe a n t ra n s p l a n t s . Fi rst , To l m an's " p u rposive b e h av i o rism" ( i n w h i c h co g n i tive e l e m en ts s u c h a s "cog n i t i ve m a ps" r e p l a ce sti m u l u s-res p o n s e b o n d s a s t he "w h at" of l earn i n g ) i l l u s­ t rates t h at t here c a n be b r i d g es b etween A m e r i c a n b e h av i o r i s m s a n d the co g n i t i v e v i ew p o i n t . T h e n t he g estalt l e a r n i n g t h e o r i es of Koh l e r , Kaffk a , We rt h e i m e r , a n d Lew i n a r e i n t rod u c ed t o s h ow a p u re r cogni t i v e a p p roac h . Ref l e ct i ng t he i r G e r m a n b ac k g ro u n d s, t hese t he o r i sts n a m ed t hei r a p p ro a c h aft er t he G e r m a n word Gestalt, w h i c h m e a n s a fo r m , s h a p e , o r f i g u re . An e m p h asis o n w h o l e st r u ct u res is i n d i cat i v e of t he g esta l t t he o r ists ' v i ew t h at l e a rn i n g a nd perc e p t i o n are m o r e t h a n t he s u m of e n v i ro n m e n t a l sti m u l i-t h e o r g a n i s m ' s i n te r n a l w o r l d m u st a l so be e x p l ored . Next, t h e cog n i t i v e - b i o l o g i c a l t he o ry of Ma r i a Mon tesso r i is s u m m ar i zed . T h e w o r k o f Ma r i a Mo n tessori l i es o u ts i d e t h e m a i nstream of psyc h o l o g y , yet i t h as b een w i d e l y a p p l i ed a n d i s o f c o n s i d erab l e i m porta n ce t o t h e psyc h o l o g y s t u d e n t i n terested i n t he fi e ld of e a r l y c h i l d hood ed u cat i o n . H e r sensory-m otor m atu rati o n a l t h e o ry , d ev e l o ped i n the s l u m s of I ta l y, p ref i g u res P i ag et, and tod ay a wor l d wi d e n etwo r k of s c h o o l s a p p l i e s h e r p r i n c i p l es i n ed u cati n g yo u n g c h i l d ren . Fi n a l l y , so m e t re n d s relevant to c u r re n t cog n i t i ve t he o r i es are i n trod u c ed . Ch apter 6 revi ews so m e a p p l i ca t i o n s d e­ r i v ed f ro m t h e t heor i es covered u p to t h i s po i n t. Ch apter 7 d i s c u sses t h e o r i es w h i c h i n c or p o rate m u lt i p l e factors i n stead o f t ry i n g t o e x p l ai n a l l l earn i n g as o c c u rri n g b y a si n g l e pro c ess. Fi rst, t h e t he o ry o f Mi l l e r a n d Do l l a rd , w h i c h att e m pts t o i n te g rate a n e o- H u l l i a n d r i v e-red u ct i o n t he o ry w i t h p r i n c i ­ p l es of Freud , i s revi ewed . T h e n t h e vari o u s stages o f Mo wrer's t h eory a r e p resented , s h ow i n g t h e evo l u t i o n of h is t h i n k i n g fro m n eo- H u l l i a n to cog n i ti v e . Fi n a l l y , t h at l o o se co l l e c t i o n of t he o r ists often referred to as t h e "f u nc t i o n a l ist s c h o o l " is d i s c u ssed. Char acterized by a p rag m at i c . i nteg rat i v e, and e c l e c t i c o r i enta t i on, t h is s c h o o l s p e c i a l ­ ized i n t h e s t u d y o f v e r b a l l e a r n i n g . Part 1 c o nc l u d es w i t h a g en eral su m m a ry a n d i nt eg rat i o n . As yo u read t h i s part, try to f i x the r e l at i o n s h i p of t h e h i sto r i c a l p ro g ress i o n of t h e o r i e s to t h e d eve l o p­ i n g t re n d s to b e p resented i n t h e second h a l f o f t h e b o o k . T h e h i sto r i c a l p ro g ress i o n was m eant t o p ro v i d e a sense o f perspective t o a i d y o u i n u n d e rsta n d i n g how s c i e n c e , ass u m pti o n s, resea r c h, a n d t h e b e l i efs o f p a r t i c u l a r h isto r i c a l p e r i od s i n teracted i n t h e d ev e l o p m en t of k n owled g e a b o u t t h is m o s t v i tal b usi n ess of l ea r n i n g . '

Basic Principles and Backg round of Pavlovian Conditioning

The type of learning called classical or Pavlovian conditioning was first system­ atically explored by Ivan Pavlov i n the Soviet Union . Because Pavlov' s work has contributed many curren tly useful insights about learning as well as much of behaviorist j argon, we will spen d considerable tim e in this chapter in going over the m a in points of Pavlov's findings and theoretical speculations . Since many of Pavlov's ideas reappear i n subsequent theories, i t is important for you to be­ come very fam iliar with his maj or ideas . Many p o ints of sim ilarity occur between Russian psychology and the psy­ chology that developed i n the United State s . B oth emphasized environmental factors rather than genetic (innate) factors i n behavior, and b o th may have done so because of sim ilar sociopolitical beliefs about the improvability of man. B o th the American Horatio Alger legend and the dream of the " New Soviet M a n" demanded o ptim istic learning theories supporting the plausib il i ty of remold i ng man i n better and more s uccessful form s . In its extreme expression , this p ositi on led to statements like those of the Am erican John Watson, who claim ed that he could take any well-formed i nfan t and make anything of h i m that anyone would want, or the Soviet s uppression of modem genetic theories i n favor of the theory of acq uired ch aracteristics proposed by L am arck and Lysenko . In the United States, t h is environmentalist b ias insured the growth of a healthy behav i oristic school of psychology, progressing from Thorndike and Watson on to H ull and Skinner and the modem proponents of behavior modification . In the Soviet Union, the congruence b e tween Pavlov's emphasis on environmental influences in changing people and the Marxist-Len inist p h ilosophy of man as improvable ensured at least i nterm ittent government support for Pavlov's research . This support in tum made p ossible h is trem endous research p roductiv i ty and h is discovery of most of the important pri nciples of contiguity-b ased learni ng. Ivan Petrovich Pavl ov (1849-1936)

Pavlov' s father was a Russian Orthodox priest i n a p oor parish who imparted to h is son a love of learning in lieu of m a terial p ossessions. Because of h is back­ ground, Pavlov was able to obta in a certificate of p overty tha t qualified h im for a scholars h ip to the University of S t . Petersburg, where he earned a degree i n natural science . He worked a t a series o f laboratory posts in physiology , win­ ning acclaim and a gold medal for h is research but little money . When he

14

The History of Lea rn ing Theory

n1arried in 1 881 , he was so poor that his wife remained living with her fam ily to save money . In the course of his work, he found t ime to earn a medical degree , and i n 1 890 was appointed professor of pharmacology. He organized and di­ rected the department of p hysiology i n the Institute of Experimental Medicine (Bab ki n , 1 949) . It was in this post that he developed the surgical techn iques that were to serve him well when he began h is s tudy of learn ing. In 1 904, he received the Nobel Prize for his work in d igestion . In th is work he noted that a sham-fed dog secre ted stomach acid when fo od was introduced i n its mouth, even thou gh a tube inserted through an open in g in the throat prevented the food from reach­ ing the stomach . Furthermore, he noted, s aliva was secreted to the sight of food as well as to the food itself. These " psych ic secretions" (Asratyan, 1953) were to provide the b asis for h is second distinguished career-th is time in the study of learn ing . Pavlov's backgro un d in physiology and the offici al Soviet emphasis on the improvab ility of men through exposure to Marxist socie ty (Cole and Cole, 1971) produced in h is theorizing a combination of an optimistic p h ilosophy related ( sometimes loosely) to precise measurement of physiological functions . Th is outlook was reflected in the official Sovi e t defini tion of human psychology as the study of consciousness (rather than of behavior, as i t was defined by the Amer­ ican behaviorists) . Of co urse , consciousness and all o ther mental p henomena were viewed as dep endent upon and originating in the functioning of the neurons of the brai n . Since mental activ i ty is totally a p ro duct of the brain, thinking in humans is seen as the same as be havior i n lower animal s . Th at is, human mental activi ty is viewed as a reaction to envi ronmental s timuli in the s ame sense that the knee j erk reflex is a reaction to the s tretch ing of a tendon, or a dog's barking may be a reflex triggered by the intrusion of a stranger . Thus, Pavlov saw all behavior as reflexive and assumed that the same basic laws described both human and animal behavior. Pavlov's approach of taki ng co mplex actions ( such as thinki ng) and tryi ng to explain them by the same laws governing less com plex actions (such as reflexes) is called the reductionistic approach . Th is approach is also the one followed by many American connectionist (cond itioning) theorists .

Classical Conditioning The first type of learn ing to be subj ected to intense scientific investigation is today called classical, respondent, or Pavl ovi an cond itioning. The basic phe­ no mena of contiguity-based lea rning were also described by Twi tmyer as early as 1904 at a meeting of psychol ogists in the Un ited States . Twi tmyer, however, was ignored . Spea ki ng in 1903 , Pavlov was the firs t to bri ng the phenomena to the atten tion of the scientific co mmunity (see Hall , 1976). The p rototypical Pavlovian experi ment goes someth ing like this: A dog s tands on a pla tform in a res tra ining harn ess . Meat powder is placed in h is mouth and he saliva tes . This saliva tion is an inherited reflex . Next , a bell is sounded j ust before the n1eat powder is put in the dog' s mouth . Th is procedure is repeated several times. Then the bell is sounded and no meat p owder is applied . The dog, however, still salivates . Th is salivation to the bell is what

Pavlovia n Con ditioning

15

rJ@(6f.-· \ \' .

©®

Fig u re 1 . 1 A typica l Pa v lovia n experimen tal situa tion . A wall p reven ts th e dog from becom ing dis tra cted by th e experimenter or from receiving uncon trolled cues from h im . Th e dog is res trained in a ha rn ess . Th e tube lea ding from the dog's mou th collec ts saliva , which drips in to a meas u ring fl.a sk on th e experimen ter's side of the wall. Th e experimenter ca n ma nip u la te th e wires con trolling ligh ts a n d sou nd-gen era ting de vices set in the wa ll between the two ha lves of the ch a mber.

Pavlov first called "psych ic secretions" (see F igure 1 . 1 ) . The dog is said to have been cond itioned to salivate to the bell . E ssentially, this con d ition ing occurs as the result of the close association between two cues : one either innately effective or p reviously learn e d , and the o ther a new cue . The firs t cue is called the unc on­ ditioned stimulus (U S) , and the new cue is called the c onditioned stimulus (CS ) . Before any condition ing has taken place, t he animal respon d s to the US wi th an appropriate reflex . This is why classical conditioning is sometimes called respondent con dition in g . The reason a given US always elicits a particular reflex is assumed to be that the part of the cerebral cortex activated by the US is p hysically connected by nerve fibers to the p art of the bra i n controlling the reflex . Because no cond i tion ing is req uired to m ake the reflex a ppear in respon se to the US, this reflex is called the unconditione d reflex (UR) . In the original Russian it was called the unconditional reflex to signify that no condition s of p rior learning were req uire d . Unfortunately, in early translations of Pavlov' s

16

The History of Lea rn ing Th eory

work, this term was mis translated and we are now s tuck wi th the term " uncon­ d i tioned . " Pavlov assumed that the result of the repeated associations of the U S a n d C S was the formation of new connections i n the brain . Wi th time, the connection between the two s timuli beco mes so s trong that the CS elicits the reflex almost as if i t were the U S . Since the p ro duction of the reflex by the CS is conditioned upon repeated associations of the two cues, this reflex (or response) is called the conditioned or con ditional reflex (CR) . Thus, thE: b asic paradigm of classical condition ing looks like this : US /

/

/

,------

U S ,----- U R

UR

I

/

cs

I

CS

I

I

L------

CR

U s u ally, the response elicited at firs t by the CS is identical to that elicited by the U S . Wi th rep eated trials, i t may become more perfunctory than the UR (Hall, 1976) . Pavlov (1960)* found that wi th many trials, often fewer drops of saliva were secreted to the CS than to the US . Pavlov s aw the role of a CS as a signal to the dog to expect the U S . Thus, the CR is, in a sense, a reflex of getting ready to respond to the US . As a " getting-ready" res p onse, i t does not need to be as s trong as the U R . This has adaptive significance because it enables an animal to respond efficiently to i ts environment . P avlov saw the function of the condition­ ing process as closely linked to biological a daptation . Complex animals need to respond to ch anging env i ronments . Th us, it is not possible for them to inheri t reflexes that would anticipate every envi ronmen tal si tuation . Nature has solved this p roblem by having evolved a mech anism to connect new environmen tal cues (CSs) to the appropriate responses . This condition ing mechanism gives higher organisms g reater flexibility in dealing wi th thei r environmen ts and makes them more likely to survive ch angi ng condi tions . To respond to the outside world, any organism mus t detect and respond to signals for action from that outside world . Pavlov called this system of s timuli or envi ron mental cues (such as the meat powder or the bell) the first signal system . Class i c a l c ond i t i oning i s a type o f l e a rning wh i c h o c c u rs w h en a new c u e ( CS) i s pai red w i t h a c u e ( U S) w h i c h h as t he p r o perty of e l i c i t i ng a ref l e x ( U R) . Aft e r t he pai ring , t h e C S a l so acq u i res t he p ro p e rty o f e l i c i ting a ref l e x ( CR) t h at i s m o re o r l ess si m i l a r t o t h e U R.

R eflexes : Th e Ph ysio logica l Basis for Classica l Co11 ditio11 i11g Basic to an understa nding of classical condi tion ing is some knowledge of what Pavlov mean t by uncondi tioned and condi tioned reflexes . Pavlov wrote: Three hun d red years ago Descartes evolved the idea of the reflex . Starting fro m the assumption that animals behaved sim ply as mach ines, he regarded every

* Pav lov (1960) refers to the 1960 Dover edit ion of l ectu re s delivered by Pavlov in 1924 . These firs t appeared in English i n a n Oxford Un iversity Press ed ition pub lished in 1 927.

Pavlovian Condition ing

17

activ i ty of the organism as a necessary reaction to some external stimulus, the connection be tween the stimulus and the response be ing made through a defin­ ite nervous path; and this connection, he stated, was the funda mental p urpose of the nervous structures in the animal body. [ Pavlov , 1 960, p. 4 ]

The essential point is that reflexes are predetermined reactions to stimul i . Th is determi n istic viewp o in t has permeated most subsequent connectionist theories of learn ing. Unconditioned reflexes are usually assumed to be "prewired" in the b rain during brain maturation in ways determ ined by the genes . The brain is innately pro grammed to recognize t he appropriate cues, which trigger the ex­ p ression of p rewired reflexes . In an actual experimental situation, it may be impossible to determine if a given reflex is of the prewired type or the result of prior learning . Reflexes may be classified i n order of complexity . The simplest would be those requiring only a sensory and a motor neuron, s uch as the knee j erk or tendon reflex elicited by t he rubber hammers of doctors d urin g p hysical exam­ ination s . Beginning at this level, reflexes can be classified as those of the spinal cord, the lower brain, and finally the outer layer of the h ig hest part of our bra in, called the cerebral cortex . Reflexes of the cereb ral cortex may b e simple, s uch as the saliv ation of the dog to meat powder, or complex, s uch as feeling a desire to imitate the actions of o thers i n a mob (the "militant enthusiasm" described by Lorenz, 1 963) . Complex reflexes are often labeled instincts . Pavlov (1960) con­ sidered " instincts" to be only complex chains of reflexes in which the whole chain could be release d by a single cue and all reflexes in the chain appeared in an innately d etermined order. There are many complex reflexes shown by higher organisms . Two examples are : the p attern of s truggl i ng in response to physical restraint ( Pavlov's " freedom reflex"), and the movements of a human newborn infant which a id her in finding her m other' s n ipple (the "rooting reflex" ) . Because of Pavlov' s background i n physiology, he saw h is investigations of complex and cond itioned reflexes as a continua tion of his investigations of t he physiology of digestion--except that he was now investigating t he p hysiology of the cerebral cortex ! D uring conditioning, the cereb ral cortex was assumed to be altered so that the portion of the cortex (called a " cortical analyzer" by Pavlov) that " no ticed" the CS became a p hysical p art of the US- UR connection . When the new connection was completed, the process of conditi oning was complete . It is not enough, however, for a complex organis m to learn to respond to new cues that signal food or sex or safety . Sometimes an animal needs to recog­ n ize cues that tell i t to stop a pattern of responding in order to survive. There­ fore, Pavlov also i nvestigated what he called inhibitory ( - ) . reflexes, which are those reflexes that act to stop o ther reflexive activity . As he classified all reflexes as either inhibitory or excitatory ( +) in nature, he also classified all stimuli as acting usually to elicit e it her inhibitory or excitatory reflexes . T h e basic u n i ts of res p o n d i n g i n P av l ov ' s t h e o ry a re ref l e xes, w h i c h a re e l i c­ i ted by st i m u l i . T hese c a n b e i n n ate or l e a r n ed , si m p l e o r c o m p l e x , a n d c a n e i t h e r e l i c i t act i o n s o r s t o p o n g o i n g act i on s .

18

The History of Lea n1 ing Theory

In hibition Pavlov considered the process of inhibition to be as i m portant as that of excita­ t ion . He d istinguished two basic types of i n h ib itio n : ( 1 ) external inhibition and (2) internal inhib ition.

Extern al inhibition

External inhibit ion can be illustrated by the importa nt type of unlearned reflex with i nhibitory components called t he orienting reflex (OR) or t he "what- is- it" reflex . In animals, this is also sometimes called t he "freezing" reflex . You h ave noticed how people hearing a new sound will st o p all motion, except to tum their heads t o localize the sound . Even i n humans, t h is action is stereotyped, often unconscious, and i nvolves very consistent changes in brain activi ty (Grossman, 1 973) . Any st imulus which aro uses the OR will stop all ongoing activity and i nterfere with the continuat i o n of previous conditioning. This i n tum set s the stage for t he occurrence of new conditioning. For cond it ioning to occur, t he subject must b e payi ng attent ion . We do not , however, give our attention to everything in our environment . If we did, we would be overloaded with trivial stimulation . Pavlov s uggested t hat our b rains have ind ependent cort ical analyzers for all t he maj or senses and that t hese ana­ lyzers decide which stimuli we should attend t o . When t he analyzers decide to p ay attention , we freeze, our muscles become taut, our brain waves become fast, and we pro duce increased adrenalin . The stimuli which trigger this innate response are of the following types : 1 . Very loud stimuli, such as a sudden backfire or a tired student' s head h i tting the desk .

2 . Very soft sti mul i , s uch as the classroom getting very, very quiet a s your head falls towards the desk. 3. N ovel stimuli, such as a new person j oining a small party , or s tim uli li kely to lead to rewards or nega tive conseq uences . Th is implies that the cortical ana­ lyzers somehow recognize all your familiar stimuli as well as the cues asso ­ ciated with conseq uences . Thus, the analyzers a re a ssu n1ed to fu nction as stimulus filters to preven t your paying active atten tion to stimuli that are familiar but inconseq uen tial , such as lecture ma terial that you have already learned will not be covered on exa ms .

In add ition, any stimulus which is s tronger t ha n the CSs or USs being studied may act as an extern al i nhib itor. The savory aroma of a pizza may act as an external inhibitor. The sudden s n1ell of the pizza may disrupt yo ur studyi ng, or an uncouth student' s vo ice in the hall o utside of a laboratory room may disru pt the conditioning of a rat . A s pecial case of th is type of external inhib ition occurs when the US is given before a well-established CS . If you have a piece of pi zza in your mouth (the US for the UR of salivation) , you will no longer res pond with fu rther increases in salivat ion to merely the sight of pizza, which would otherwise be a CS for increased s alivation .

In tern al i n h ibitio n

Pavlov assumed that the cort ical analyzers somehow d is­ tinguished novel and/or im portant stimuli from fam iliar unimportant st imuli . This internal process results in the inhibition of attention responses (the OR) to

Pavlo vian Con ditioning

19

fam iliar unimportant cue s . This process i s called hab ituation. The inhibitory effects of habituation can i n tum be inhibited by t he occurrence of a m ild inhibitory s timulus in the environment. This last p rocess is called disinhibition . P avlov h a s described an experiment in which a dog w a s tra ined t o s alivate to the appearance of a rotating object ( the CS) . Then this res ponse was inhibited . When t he dog was transferred to a n ew experimental room, the effect of the " n ew room cues" was temporarily to inhibit t he inhibi tion, and the dog again salivated to t he sight of rotating fig ures ( Pavlov, 1 960) . The " new room cues" (novel cues) in this example operated as external i n h ib itors and p robably elic­ ited the OR. Inhibition may also b e tra nsferred to new stimuli by conditioning . In this type of condi tioned inhibition, something w hich w as formerly a weak CS or US for an excitatory reflex may come to i nhib it that reflex if p aired freq uently w i th a strong inhibitory US . This changing of the respon se elicited by a given CS is also c alled counterconditioning. After many m onths of working i n a pizza parl or, even t he word " pizza" may become an i nhibiting CS . After months of shrill complaint associated w i th sexual activity, t he sight of the p artner's n ude body may only elicit t he cond i tioned inhibitory response of impotence or frigidity . The movie A Clockwork Orange , directed b y Stanley Kubrick, vividly illus­ trated the process of inhibitory conditioning. The main character is a s poiled youth w ho se main j oys are brutali ty and Beethoven . F inally, "Little Alex" is betrayed by h is fellow j uvenile thugs and imprisoned . G iven a choice between continued prison life and a " scien tific program, " L i ttle Alex chooses t he treat­ ment program . Treatment consists of dosing him with a drug that makes him feel nauseous and as if he "wishes to die" ( the US) . H is eyes are t hen clamped open and, before the drug ' s effects begin, a p ro gram of films about atrocities, rapes, and o ther violent acts is begun , which he hugely enj oys. Gradually h is enj oyment turns to panic a s t he drug's effects become apparent . With repeated sessions, acts or scenes of sex or violence are counterconditioned to b ecome excitatory CSs for t he CRs of nausea and fear, w h ich inhibit aggressive and sexual reflexes and (presumably) thoughts . To demonstrate the success of their pro gram, t he "therapists" lead Little Alex o u t onto a stage in front of a large audience . A h alf-nude girl appro aches and L ittle Alex approaches her with i n tent to moles t . He is immediately seized wi th the CRs of nausea and dread and falls to the stage . By t he end of the demonstration, her mere appro ach is enough to make him tum away and the audience applaud s . Soon h is very urges towards sex and violence become inhib­ i ted . What were once very excitatory cues have now become powerful inhibitory cue s ! As a final cruelty (or act of j us tice), t he pro gram adminis trators played Beethoven d uring the con ditioning process . As a result, Little Alex is no longer able to stand the sound of w ha t had formerly b een h is one nonpathological source of comfort. C on di tioned inhibition may also occur following d iscrim ination training. W hen one ton e is p aired with food and another tone is never paired with foo d , any cues associated with the nonreinforced cue m ay also acquire conditioned in hi b i tory properties . This process is called " differen ti al i n hi bi ti o n , " and may

} (

)

20

The History of Lea rn ing Theory

be the way we learn to focus on the specific things that are adap tive for u s . Some people may never reinforce us, and eventually we perceive them as surrounded by "bad vibrations, " which may be condi tioned inh ibitory cues . Another typ e of i n ternal inhibition is extinction (the loss of the power of the CS to elicit the CR as the result of several trials without the p resence of the US) . Examples include loss of salivation to the sight of ice crea m after working i n an ice cream parlor or loss of physiological arous al to nudity after a frustrating summer at a nude beach . The probable U Ss would be ice cream i n the mouth and tactile stimulati on in your erogenous zones, resp ectively . This will be d is­ cussed further i n the next part. A final note on i nh ib i tion is appropriate here . Pavlov (1960) suggested that the brain processes responsible for the types of inhibi tion d iscussed so far are identical to those responsible for slee p . In fact, he thought that conditioned inhib i tion is caused by local areas of the b rain entering i nto a sleeplike state and that the i nhibition of a person's will when in a hypnotic trance represents partial sleep . As we have seen, inhibi tory conditioning involves the active process of i nterfering with the elicitation of some reflexes . It is hard to see how such effects could be produced by the same p rocess responsible for turning off parts of the brain in sleep . Pavlov's process of intern al inhibition may be derived from nothing more than observa tions of the absence of exci tation . In other words, Pavlov evokes the process of inhibi tion to accoun t for most phenomena which do not seem to fit the laws of exci tatory phenomena . I n h i b i t o ry refl e xes are o f two b as i c types : ( 1 ) t ho s e e l i c i t e d b y exte r n a l c u es w h i c h c a n be effe c t i v e w i t h o u t l earn i n g ( e xt e r n a l i n h i b i t i o n ) , a n d (2) t h o s e req u i ri n g s o m e s o rt of l ea r n i n g p r o cess ( i n t e r n a l i n h i b i t i o n ) .

The S tages of Conditioning a n d Extinction As previously mentioned, the orienting reflex plays a vi tal role in condi ti oning . Leaming cannot occur unless you first pay attention to the CS and US and then settle down to the business of being conditioned . Therefore, the firs t stage in the cond itioning process is the elici tation and habitua tion of the OR. After this has occurred, and with several addi tional pa irings of the CS and US, the CS be­ comes capable of elici ting the reflex (now called the CR) . If the CS is presented several ti mes in s uccession wi thout being followed by the US, the CR vanishe s . This process is called experin1ental extinction . Th is does not mean, however, that the subj ect has forgotten the CS-US relationship or that it is restored to its preconditioning state . If the exti nction trials are followed by a rest period , upon the next presen ta tion of the CS it will again be effective in eliciting the CR, altho ugh us ually not as s trongly as before. This phenomenon is called s p ontane­ ous recovery . If the CS is s till not followed by a US, the spontaneously recovered CR will us ually reextinguis h q uickly . In general, classical cond ition ing extinguishes rapi dly . There are ways to com pensate for the lack of durabili ty of s uch learning, however. Pavlov ( 1960) notes that after several cond i ti oning and extinction sessions have b een giv en on successive days, ext incti on us uall y is slower. In general, anything which re-

Pavlovia n Conditioning

21

duces the organism's ability to predict when the US (the reinforcer, i n Pavlovian literature) will not follow the CS makes the cond itioning more resistant to extinction . The s trength of the cond itioning may also d epend u pon the intensity of the original US . The s tronger the US is, the more likely the learni n g will be resistant to extinction . Very strong USs, for instance a d og b i ting you, m ay res ult in durable , one- trial learn i ng . When this is a negative emotion al experience , it is called a traumatic exp erience. B ehavior therapists ( in Kanfer and Phillips, 1 9 70) have suggested that this typ e of classical cond iti oning may be responsible for m any p hobias, or u nreasonably strong aversions that have been over­ generalized . Pleasant or not, t he conditioning that results from very stron g USs is often h ighly resistant to extinction . S uch learning may persist for a p atient's entire life . A person w ho first confronted a dog i n the company of h is hysterical mother may never again get close enough to any dog to d iscover that dogs are far less fearsome than he was con d itioned to b elieve . Yet another way to i ncrease the d urability of con ditioning is to pair the same CS with multiple USs . For exam­ ple, money is paired w i th foo d , meeting social and stimulus n eeds, and social approval. If you are confronted wi th a situation in which no resta uran ts are open to allow you to exchange your money for food, you do not feel significan tly less emotionally a ttached to your m oney . Of course, if you had foreign currency w h ich you could neither spend nor exchange, i ts conditioned positive value for you would p robably extinguish with time and repeated extinction tri al s . Such a CS , which is a signal for many reinforcers, h as been labeled by the Skinnerians as a generalized secondary ( or c on ditioned) reinforcer. For c o n d i t i on i n g t o o c c u r , t h e O R m u st fi rst be e l i c i ted a n d t h e n h a b i t u ated . Presentat i on o f a CS a l o n e ( e x pe r i m e ntal e xt i ncti o n ) res u l ts i n i ts ceasi n g to e l ic i t a CR. Fo l l ow i n g a rest p e ri o d , however, the CS w i l l s po n t a n e o u s l y re­ cover so m e of i ts p o we r t o e l ic i t the CR.

Discrimina tion a nd Generaliza tion In addition to learning to resp ond to new signals from t he envi ronment, the organism must learn to d istinguish the cues which should signal different re­ flexes . This process is usually labeled d iscrimination, although Pavlov preferred the term differentiation . Pavlov a ttempted to explain this learning process i n terms of cortical functioning. He thought repeated trials with a CS triggered a physiological process i n w h ich excitation was concentrated a t the site i n the bra in aroused by that C S . I f t hese conditioning trials were randomly alterna ted with trials in which a no ther cue was presented that was never reinforced by t he US , this nonrei nforced cue would b ecome a signal not to respond . Presentation of the nonreinforced cue was supp osed to b uild up an inhibitory potential i n i ts cortical analyzer, so eventually the reflex would occur only following the CS, a nd never after t he unreinforced cue ( Pavlov, 1 960) . In the process of cond i tion ing, a CR will come to be evoked by s timuli similar i n some d imension to the original CS. For instance, if someone you love always says, " Hey, you," in a soft voice ( the CS) before doing something ( the

22

Tlze History of Lea rn ing Theory

US) which always makes you blush (the UR) , eventu ally you will blush to the words " Hey, you . " If they then subs titute the words " Hello , you , " you may then b lush to those words, too , but not quite so much . Other words that are more d ifferen t from the original CS will evoke a weaker " conditioned blushing reflex . " This p henomenon is important in allowing the organism to respond to a range of cues w h ich may b e signaling the same US as the training CS . Th is process is called stimulus generalization, and Pavlov explains it as a process o f irra diation (spread in g from the focal point excited by the original CS) o f excita­ tion within the cortex . Since stimuli most similar to the CS are p rocessed in places in the cortex near the site excited by the CS, those s timuli receive the most irradiated excitation and are the most likely to have enough excitatory poten tial to result in responses . Not only is excitation generalized , but also the inhibition built up during extinction generalizes through the irradiation of i n h ib ition fro m the inhib itory CS in the cortex ( Pavlov, 1 960) . Dis c ri m i nat i o n a n d g e n e ra l izati o n a re two o p p os i n g p r o c ess es . Di s c r i m i n a­ t i o n is d is t i n g u is h i n g CSs fro m other c u es . G e n er a l izati o n is a t e n d ency t o r e s p o n d t o c u es w h i c h a re s i m i l a r t o a CS, a l m os t as i f t h ey w e r e t h e CS.

The Basic Types of Conditioning The general p rocess of classical conditioning has been' described previously. Several typ es of classical cond itioning, however, have b een distinguished on the basis of the experimental procedures used to produce them .

Prim a ry conditioning

Sam ( the CS) alw ays stumbles over your feet, causing pain (the US) , w hich is innately connected to the aggression response (the UR) . After several such inciden ts, you feel angry whenever Sam gets near your feet . If Sam enrolls in Arthur Murray' s tan talizing tango class and is allowed to walk near eno ugh to yo ur feet to demons trate that he is no longer the heavy- heeled marauder, extinction will take place . If he is so overj oyed by your recovery fro m your " Sam- phobia" that he d ances aroun d (a novel cue) , yo u may show disin­ hibition or recovery of the conditioned aggression response. If the aggression response is extinguished and subsequently Sam vanishes fro m your life, a re­ turn of aggression , coinciding with the return of Sam , represents spontaneous recovery. Another exa mple of pri mary conditioning might be experiencing stomach " rumbles" when yo u view a clock whose hands i ndicate that it is dinner tim e . Schacter ( 1 971 ) fo und that obese people tend to e a t more than thin people and experience stomach con tractions when shown a clock whose hands had been moved from the real tim e (say, 10 A . M . ) to noon . The sight of the clock (the CS) must have preceded whatever internal physiological states (USs) normally triggered feelings of hunger many times, before the clock alone became an effective CS . Any cue (wh ich can be an envi ronn1 ental cue, a p hysiological state which is detectable , or thoughts i n humans) which has a strong prewired or innate bond with a UR (which is us ually a smooth or visceral muscle response or a thought in

Pavlovia n Co11 ditio11i11g

23

humans) can be a US . This combination can be paired w i th almos t any d iscri­ minable cue inside or o u tside of the organism to serve as a C S . Pavlov ( 1 960) , however, stated that the aftereffects of external cues usually persis ted for m i n ­ u tes at most, while the aftereffects o f visceral a n d odor cues might last days . Thus, all cues may not be eq ually cond i tionable . He also noted that many cues elici ted both motor and secretory reflexes rather than operating in a simple fashion to elicit one particular reflex . In general, CSs to which the subj ects were originally ind ifferent were foun d to cond i tion most easily . Primary con d i tioning procedures in which the CS is presented j ust before the onset of the US h ave been the most commonly employed p rocedures and us ually are most effective in producing conditioning. These are c alled delayed proce­ d ures, and half-second CS- US i ntervals seem generally mos t effectiv e . These p rocedures are d istinguished from procedures in which the CS and US are p resen ted simultaneously, which are usually less effective (Hall, 1976) .

D efense con dition ing

A s pecial type or primary con ditioning procedure must now be examined . This is the paradigm explored by Bekhterev, a contem­ porary rival of Pavlov's . In this metho d, the CS (usually a tone) was followed by an electric s hock to the forepaw of a dog. At first, only the s hock (the US) elicited the UR o f a flexion response of the paw . E ven tually the dog would withdraw the forepaw to the tone alone ( in Tarpy, 1975) . Because leg flexion to the tone would protect the dog from experiencing s ubseq uent s hocks such a defen se con d i tion­ ing shares aspects of b oth classical and reinforcement conditi oning.

Second- order condition ing

When the U S is a cue tha t was formerly a CS, rather than being innately connected to an UR as in primary con ditioning, the cond itioning is called second- order conditioning. If meat in your mouth ( wh ich is the US for the reflex of salivation) is preceded by the smell of cooking ( the CS), then the smell of cooking may even tually be enough to elicit the CR of the salivation . If the cue of turn i ng on the s to ve then always precedes the smell of cookin g, the sound of a s to ve i gn iting m ay even tually trigger s alivation . In general, the CRs to a second-order CS are weaker than the CRs to a primary CS . Another example m i gh t be the touch of another person on your s kin ( the US) eliciting the reflex of arousal (the UR) . The person is the CS; w i th enough trials, his or her presence alone may trigger an arousal reflex . If the person is paired reliably with a s pecial song even in the absence (or it wo uld not be secondary conditioning) of any touches, the song m ay act as a secondary CS for the arousal CR ( that is what m akes the song so spec i al) . Later, the song will elicit the response even if the person is no longer in your life. A note of caution is necessary here . If several cues are present at the same time, they are all potential primary CSs � nd none of them s ho uld be considered a secondary CS . In our example, if you had heard the song while the person was touch ing you, t he condi tion in g would be d i rect, and both the person and the song would be primary CSs . Even h igher- order conditioning is possible, although the CRs may be weaker. Pavlov (1 960) reported an experiment in which shock to the fron t paw (US) of a dog was paired wi th tactile stimulation of the hind paw (CS) . Tac tile

24

The History of Lea nz ing Theory

stim ulation of the hind paw was then paired with the soun d of b ubbling water (the second- order CS) . F inally, the water sound was paired with a tone of 760 Hz, which became a third -order CS . Hi gher-order cond itioning tends to extin­ guish easily and b e difficult to p roduce . Pairing a second - order CS with multiple p rimary CSs (as our generalized secondary reinforcers ) , however, makes a stronger bond .

B ack1oard conditioning

In this parad igm, t he CS follo7.vs the US rather than servi ng as a signal for its arrival . An example would be p utting meat in your mouth (the US) and hearing your mother say , "Yum" (the C S) . If this CS gained the power to elicit salivation (the CR), then conditioning would have occurred which had no signal or biologically useful function . In fact, because such cond itioning serves no warning or signaling function, its existence was in doubt for many years . Pavlov (1960) first said such learn i n g w a s impossible and later reversed this negative stanc._e (in Hall, 1 976) . Although many researchers have claimed to have demonstrated that backward condition­ ing (also known as pseudoconditioning) does occur, many others have been unable to replicate these results (in Hall, 1 976) . Hall concluded that because a control procedure using cues other than the " CS -to-be" was not used in many of the affirmative studies, it is difficult to determine if backward cond itioning does in fact occur. The reason why the random presentation of new cues is so important as an experimental control procedure is because of a phenomenon called sensiti­ zation . The sequence o f presentation of the cues i n backward conditioning is shown as follows .

_J

lJ

T i m e ----.11)1Jo--

�--------�! cs LJ CR ? I.__ US

UR

_ _

Sensi tization is a general state of aro us al which occurs after exposure to a strong U S , s uch as a shock or a b right ligh t . When an organism is sensitized, it may be so nervous that it will respond to any cue presented to it. If you presen t only one cue (which you hope will become a CS) the subj ect will respond to that cue-no t beca use it is cond itioned but because it is sensitized . If you had presented a random order of novel cues, it would have responded to all of them also . A human example of sensitiza tion wo uld be the tendency to jump at every small no ise j ust after being almost hit by an auton1obile while trying to walk across the street. Sensitization must always be controlled for in attempts to demonstrate classical cond ition ing .

Tra ce co11 ditioni11g

Pavlov assun1ed that the presentation of a CS made a physiological mod ification of the cerebral cortex in the form of a neural trace or area of altere d activity . The term trace conditioning is derived from the assump ­ tion that such traces could initiate reflexes some time after the CS had been presen ted. The assumpt ion o f such traces was necess ary to account for condi­ tion ing which deviated fro m the normal p rocedure of giving the CS about . 5 seconds before the US-since with delays between CS presentation and US

Pavlovian Conditioning

25

p resentation, there could be no overlap between the cortex's resp onses to the cues . In trace conditioning, therefore , the b ond is between t he trace of the CS and the area of the cortex excited by t he US . Pavlov d istinguished between s hort trace con ditioning, where the time delay between CS and US was under 1 m inute, and long trace condi tioning, where the delay was over 1 minute . For example, a tactile stimulus is presented (the CS) ; after 30 seconds, a weak acid is inj ected in the mouth ( the US) , pro ducing the alimen tary defense reac­ tion of salivati on (the UR) . After several trials ( Pavlov, 1 960) , the subj ect begins to salivate following the application of the touch and continues to salivate for abo u t 40 seconds ( or un til the US w ould have been applied and dissolved) . With more trials, t he s ubj ect does not salivate when t he CS is applied, b ut after abo u t 3 0 seconds ( or w hen the US would have been applied) begins a 1 0 - second bout of salivation . Trace conditioning also illustrates a type of i n ternal inhib i tion called the " in hib i ti on of delay . " This is the process by w hich t he CR is only given a t the time at which the US would have been given, rather than during the entire interval between the CS and the appropriate tim e . An example m ight be waking up freq uently the first few n ights when you h ave an early j ob or class, until you become conditioned to the new time interval and wake up only j us t before the alarm clock gladdens your heart with i ts merry b uzzing. You have conditioned an i nhib ition of your waking until j us t before the US ( the alarm) .

Temporal condition ing

The following example illustrates this type of

cond itioning . A dog is placed in the stand and given food regularly every 30th min ute . In the control experiment a ny one feeding after the first few is o m i tted , and it is found that despi te the omission a secretion of saliv a wi th a corresponding alimenta ry motor reaction is pro duced at about the 30th m in ute , but it may be one or two minutes late . I n the interval there is not the least sign of any alimentary reaction , especially if the routine has been repeated a good number of t i me s . When we co me to seek an i n terpretation of these results, it seems pretty evident that the dura tion of time has acq uired the properties of a condi tione d sti m ulus . [Pavlov, 1960, p. 4 1 ]

The next example s ho uld be more fam iliar to many of you. Again it illus­ trates that i n temporal conditioning, time itself is t he CS . You have the m isfor­ tune to have to take an 8 : 00 A . M . class . Every morning at 7 :30 A . M . , your sleep is rudely s hattered by the insistent braying of your alarm clock ( the US) which immed iately elicits the UR of a utomatic (visceral) nervous system and behav­ ioral aro us al ( the OR) fro m your comfortable sleepi n g s ta te . After many d ays of being awakened at the s ame time, you m ay begin to wake up before t he alarm shatters your dreams . This "conditioned" awakening depends upon a s pecific time interval somehow acq uiring the properties of a CS . Although it is still not clear how an interval of time can become a CS, i t is p ossible that changes in blood s ugar throughout t he n ight may be the real CS and that we p ossess "b iological clocks" i n the b ra in . It is now known that h um ans do h ave internal clocks which can be modified w i th time . When t he w orld does not match our internal CSs for eating and sleepi ng after a l ong j e t

26

The History of Lea n1 ing Theory

plane t rip, we may feel extremely d isoriented until our internal clocks are recon­ ditioned to our o utside environment. Several ty pes of c o n d i t i on i n g p ro ced u res h ave been d isti n g u i s h e d . These a r e : ( 1 ) p ri m ary c o n d i t i o n i n g , (2) d efense c o n d i t i o n i n g , (3) s e c on d - o r d e r c o n d i­ t i on i n g , ( 4) b a c kward c o n d i t i on i n g , (5) t ra c e c o n d i t i o n i n g , a n d ( 6 ) t e m poral c on d i t i o n i n g .

Effects of Com bina tions of Excita tory a n d In h ibitory S tim u li The effects of combining CSs may not always be obvious from the individu al properties of the cues . If several weak + CSs* are added, they may summate to produce a CR even though they are individually too weak (p erhaps because of p rior extinction) to elicit any respon se s . An exam ple might be co mbining food odors and the nearness of lunchtime to produce a CR of s alivation . If many + CSs and - CSst are alternated , the resis tance to extinction of the CRs to the + CSs will increase . This is somewhat like alternating cond itioning wi th extinction several times to produce a more durable trace . I f the cues re­ sponsible for salivation are alternated wi th fear cues which pro duce dry mouth, the conditioned cues for s alivation will remain effective even in the prolonged ' absence of the USs for salivation . It is also possible to present + CSs and - CSs simultaneously . This combina­ tion of cues (a new com pound stimulus) may have effects d ifferent fro m either co mponen t . These effects may be q uite co mplicated . A combination of food odors and the time cue of 1 0 : 00 A . M . may be inhibi tory (inhibi tion of delay creating the conditioned inhibition of s alivation) , unless a s trong distraction results in d isinh ib i tion, in which case the new combination may elicit copious salivation . If the brain alpha rhythm is conditioned to a tone ( to produce con­ ditioned relaxation) and a n ew cue to relax is then given, the alpha rhythm will vanis h .

O ther effects of conz bined

and

infiu ences

I f very strong or extraordi­ nary excitatory ( + ) and inhibi tory ( - ) stimuli are combined, a conditioned neurosis may res ul t . This may be demonstrated in various way s . Pavlov trained dogs to respond to circles and not to respond (inhibition) to ellipses . He then made the two fi gures more and more like each other. When the dogs were unable to discrim inate the fig ures ( the + and - cues were comb ined) and the dogs were in conflict, the normally calm an imals became extremely upset. When they were return ed to problem s that they had formerly found extremely easy , they refused to pay attention to them, urinated, and became d ifficult to handle . Pavlov assumed that the cause was the clashing of excitatory and inhibitory processes in the brain, which produced a disconnected response con ditioned to +

-

* + CS = a CS that elicits an excita tory response or reflex . - CS = a CS which blocks exci tatory reflexes (such as saliva tion) and elicits a defensive reflex. These are usually cues wh ich signal the occurrence o f aversive events . t

Pavlovian Con dition ing

27

the confusing s ti m ulus . With repeated trials, t hese d isconnected responses were assumed to generalize ( sp read) to anything similar to t he test stimulus, which p revented respon ses, o ther than the d isconnected m alaqaptive res p onses, being given even to rea dily d iscriminable circles and elli pses ( Pavlov, 1 960) . Because Pavlov s aw the p ro cesses of inhibition and excitation as pro d ucing fields of activ i ty or s uppression i n the cortex of the cerebrum, he s uggested that these field s might p ro duce field effects similar to p hysical electrical fields . One of the effects he described was induction, wherein p rolonge d activ i ty of one sign causes a " bounce-back" or afterim age of the opposite sign after a p eriod of time . He used the example of the sudden b urst of frenetic ( + ) activ i ty often seen in small sleepy children, after they h ave been incre asingly d rowsy j ust before going to bed and/or slee p . Ano ther example m ight be the sudden fit of depres­ sion that often follows euphoria , as when some one feels depressed following t he excitemen t o f a gra duation ceremony . W h e n m o r e t h a n o n e CS is p res e n te d s i m u lt a n e ou s l y, t h is c o m p o u nd s t i m u ­ l u s m ay h av e p ro p e rt i es d i ffe r e n t f r o m t h os e o f i ts c o m p o n e n ts . C o m b i n a­ t i o n s o f s t r o n g sti m u l i so m et i m es p ro d u ce a c on d i t i o n ed n e u rosis.

From La bora tory to Rea l Life Verba l behavior a nd o ther com plex reflexes

You m ay p ro test at this point that h umans often think b efore behaving, and that in any case h uman behav i or is m ore complex than simple stim ulus-resp onse connection s . Pavlov, however, explained that verbal thoughts and overt s peech constituted a second signal system whic h operated much l ike the environmen ta l cue or first signal system . He even hypothesized that a thought res ulting from another thought was as much a predetermined C R as any alimen tary response ( although he was never q uite sure) . Just as the taste of a steak elicits a s aliva ry res p onse ( does this apply to vegetarians?), so does a conversation about j uicy, ten der, savory steaks or even thoughts of luscious thick steaks smothered in mushrooms . Hence in h u ­ mans ( a n d probably only in h um an s ) , the meanings of words become con­ ditioned to a variety of USs in the environment and gain the p ower to elicit reflexes . We h ave not only a second sign al system ( verbal cues) but also a secon d reflex system (words a n d though ts) . The basic rules an d operations , however, are assumed to be the s ame for b oth systems . Although Pavlov recognized tha t it was sometimes d i fficult trying t o explain complex h u m a n behavior i n terms o f the p rinciples derived from research on dogs, he felt that further exploration o f the laws of con dition in g would make such explanations p o ssible . It would be the height of presumption to regard these firs t s teps in elucidating the physiology of the cortex as solving the intricate problem s of the higher psychic activ ities in man, when in fact a t the present state of our work no detailed application of i ts results to man is permissible . N evertheless, inasmuch a s the h igher nervous activ i ty exh ib i ted by the cortex rests, u n do ubtedly on the same fo und a tion in man as in h igher animals, some very general and tenta tive i nferences can even now be drawn from the latter to the former. In the future it may confidently be expected tha t a full and

28

Tlze History of L ea rn ing Th eory

detailed knowledge of at least the elementa ry facts of this activ i ty will be ob­ tained as regard s both normal and pathological states . [ Pavlov, 1 960, p. 365 ]

Wi th a spirit both hopeful and h umble, Pavlov a ttempted to generalize his findings to man . He considered habits acq uired thro ugh training and educati on to be nothing but long chains of conditioned reflexes. Such a ssociations, once learned, co uld be automatically elicited by app ro priate CSs, even again st our \Vill s . For example, consider the great difficulty encoun tered in trying to get rid of superfluous movements in ski ing, gymna stics, or other skilled complex acts. As further proof of the reflex chain theory of complex skill s, Pavlov cites the example of trying to stop midw ay in the process of tying your shoe, waiting, and then resuming the ch ain . Because each act is the C S for the n ext act, the wait causes the cortical representation of that CS to decay, m aki ng the resumption of shoe tyi ng awkward . Although such an explanation is app ealing, Pavlov nev er specified the un derlying UR from which the ch a in of CRs was suppose dly derived . Pavlov also s uggested that s uch reflex chains co ul d be inhib ited by adding extra stimuli (which would , of course, elicit the OR) . Further examples might be the disorien tation experienced when you attempt to break a long-es tablished ro utine, as going to school or work the same w ay each day, or the difficulty of resuming the routine CRs of studying (as p age turning, underlining, and simi ­ l a r acts, in which each C R serves both as C R and a s C S for the next ro utine action) when your involvement in this activi ty is interrupted . As opposed to the smooth, efficient action of habit, the conscious control of study is laborious and slow . Of course, the danger exists that late in a study session you may find yourself emitting the " reading chain reflex" wi thout understanding or memorizing any of those pages inspected by your weary eyes . Pavlov also discovered that as CSs of the weak and monotonous variety habi tuate, they beco me CSs for that profo un d cortical inhib ition known as sleep . Hence yo ur fatigue in reading may be the result of the rep etition of the inhibiting CSs of non- understandable and irrelevant facts . In this context, becoming bored in lectu re is a function of your not making the material i mportant to you, and falling asleep in class may be a reflexive respon se to the monotono us CSs emit­ ted by the professor rather than ei ther real fatigue or malice on your part.

Conditioning a n d Abnonnal Behavior Pavlov applied his theories to abnormal behavior a s well as to theories of educa­ tion . He considered neurosis and p sychosis to be d ifferent only in the amo unt of disturbed cortex involved . Neurosis, he believed, is the res ult of functional disturbances . fur example, traumas are the res ult of exposure to very strong s ti muli which overload the nervo us system and ca use irradi ation of excitation or inhibition of areas of the cortex responsible for norm al behavior. Th is causes anxiety to be elicited by too wide a range of CSs, as when one bad experience with dogs generalizes to a pathological fear (p hob ia) of all d ogs . Pavlov suggested that another cause of neurosis is the i n ability to express emotion s . Th is, he hypothesized, leads to abnormal levels of inhibition or de­ pression . This concept is of co urse very similar to Freud ' s theory of neuro sis,

Pavlovian Con ditioning

29

which assumed that blocking of i d-produced ( instinctual energies or d rives) emotion al expression by the super- ego or conscience (which Pavlov might see as reflexive second signal system activ i ty) could cause neuro tic behavior. Neurosis could also result from an unus ual clashing of excitatory and inhib­ itory processes i n the cortex as the end products of conflicts . This theory later appears in Wes tern p sychology in the learn ing appro ach to psychop athology p rop ounded by Dollard and Miller (see Chapter 7) . Pavlov predicted that the res ul t of such conflicts in persons with strong nervous systems would be a s tate like hypochondri a (an exaggerated concern with b odily symptoms of " illness"), typified by altern ating high levels of activi ty and subseq uent exhaustion . Per­ son s wi th weaker nervous sys tems (or more d ominated by inhibition) were predicted to be more p rone to agitated and nonuseful activi ty , as their inhib­ i tory processes were d isrupted by the surging b ack and forth of alternating w aves of tendencies tow ards excitation and inhibition . Pavlov assumed tha t most severe mental illnesses were the result of the destruction of l arge areas of the cortex, which unhin ged the b alance between excitatory and inhibitory areas. Catatonic psychotics were seen as havin g weakened n ervous systems that allowed a n y s timulus to induce m o tor inhi ­ b i tions . Pavlov s uggested giving weak and m onotonou s C S s related t o the CSs i nv olved in clashing · of + and - cues or traumatic experiences . He p redicted that such weak presen tations would eventually reciprocally inhib i t the CSs re­ s p onsible for the abnormal behavi or. This is, of course, t he b asis for Wolpe's reci p rocal inhibi tion method of treatmen t. In the form of systematic desensitiza­ tion ( d iscussed i n Chapter 6) , it is a maj or tool of cl in ical behav i oral modifica­ tion . Pavlov a ssumed that the treatment he advocated led to a s tate of cortical inhibi tion or a p hysiological state of the b rain conducive to not responding in the former p atholo gical m anner. Conversely, cortical i n hibition which pre­ vented good behaviors ( as in unreasonable fears) would also be pathological . Even courage and cowardice were explained i n terms of cortical inhibition : Developing these conceptions further we are bound to regard the obsession of fear, and different phobias as natu ral symptoms of inhibi tion in a pathological and weakened n ervous syste m . There are of course, certain forms of fear and coward icer as for instance flight and panic, and certain posture s of servility , which apparently do not conform wi th the idea o f an underlyi ng inhibitory process, h av i ng a much more active aspect. These type s must, of course, be subj ected to experi men tal analysis, but i t is perh aps not i m permissible to regard them provision ally as developing in co-operation with , and a s a result of, inhi­ b i tion of the cortex . [ Pavlov, 1960, p. 410]

Pavlov's Positions on Major Issues Na ture/n urtu re P avlov believed that m any complex reflexes, including the reflex to escape restraints ( the freedom reflex), the reflex of self- defense (Pavlov, 1960) , and the orienting reflex, are innate . In addition , he postulated innate differences in the capacity to form con ditioned traces, d ep en ding upon the type of n ervous system inherited . He s uggested tha t some indi vi duals of any species inherit nervous s ystems domin ated by inh ibi tion an d o thers inherit nervous

30

The History of Lea rn ing Theory

syste ms dominated by excitation . Indivi d uals w i th inh ibi tory dominance could learn inh ibitions more easily than positive responses, and vice versa . These inherited factors, however, only served to bias the effects of the more i mportan t environmental shapers of behavior.

The how of learn ing

The primary basis for the formation of new bon ds is the reinforcemen t of a CS by a subsequent US . If the inhibitory effects of fatigue are avoided, the strength of the bond is a function of the number of " reinforced" trials . Drive, however, can set the s tage for lea rn i n g . Con ditioning of the salivary response cannot occur unless the UR is p ossible . I f the animal is not h ungry, then the UR is not possible and no learni n g can occur. Actual learning, of course, is solely a matter of contiguity-association factors .

The zvh a t of learning

The unit of learning wh ich Pavlov discussed in most detail was the formation of new connect ions in the cerebral cortices between the centers excited by a new cue (CS) and those controlli n g response s . Th is new connecting firs t i nvolves the formation of a b ond b etween an US and the C S . I n the case o f complex new responses, connections have t o b e made between the simple reflexes participating in the new resp onse . I n any case, the un it is bonds between stimuli and stimuli, betw een stim uli and responses, and between re­ sponses . When the responses involved are h ighly complex, the behavior unit can be large or molar. When a simple glandular response is conditioned, the unit can b e very small or molecular.

O ther issues

In most of the animal studies he reported ( Pavlov , 1960) , learn ­ ing, as measured by the increasing p ower of the CS to elicit the CR, is gradual. This wo uld s uggest a mechanis m of the gradual strengthen ing of b onds among the S and R elements . In human learning, however, simple CS- CR relationships may be learned i n a single trial . Pavlov had no use for the concepts of under­ s tanding and insight, so his explanation of the phenomena took two forn1s : First, man can signal h imself vi a the second signal system of tho u ght and lan­ guage and hence perform the ·eq uivalen t of in tern ally condi tion ing traces . In addi tion, Pavlov' s conception of reflex was so b road that he was willing to extend concepts, s uch as u tilization of knowledge or acq uired connections in new situations, to animals . "Th is is the ch aracteristic associ ationist view of understandin g : the utiliza tion of past experience through some kind of transfer" (Hilgard and Bower, 1 975, p . 86) . Pavlov was, o f course, willing to generalize the learning laws derived from animal research to human behavi or, and he saw behavior as envi ron mentally determ ined , with the q ualification that hun1an speech co uld function as part of an interior environment. Cha p ter Perspective

Almost any type of stimulation in the environm ent ( includ ing a s ti mulus's get­ ting softer or d i m mer) can serve as a CS, which introduces a problem in deter­ m ining precisely the relationship between a controlled CS and the cond itioning.

Pavlovian Con ditioning

31

I n the United States, the difficulty o f controlli n g extra CSs lim i ted explorations into classical condition ing . In the Soviet Union , Pavlov' s prestige prompted a "keen and p ublic- spirited M oscow b usinessman" ( Pavlov , 1 960, p . 20) to donate the fun d s to b uild Pavlov's elaborate laboratory i n Petrograd as an a dj unct to the Institute of Experimental Medicine. This laboratory contained chambers to sep a­ rate the experimental animals and t he scientists, w i th every chamber insul ated against o utside noise and light. In addition , the entire b uilding was s urrounded by a m o at to d ampen the vibra tions of trucks passing o utsid e . To illustrate the problem , imagine a situation i n which the sound o f a metronome is used as the CS to be applied j us t before application of meat p owder to t he mouth of a dog . After a w h ile , the sound of the metronome becomes effective i n eliciting s alivation . After m ore time, t he dog may begin to s alivate to the approach of the experimen ter, who h as now also b ecome a C S . The animal m ay even begin t o salivate when bro ught into the roo m a n d fastened in the h arness . The h arness is necessary to prevent t he animal fro m finding its own CSs or indulging i n competing responses and to permit accurate measure­ ment of desired response s . It i s b ad enough that the dog might s alivate to the appearance of the w hite lab coat of the experimenter. Wha t m akes the p roblem even m ore compl ic ated is that i t is d ifficult to interpret how the coat pro duces i ts effect. Was s alivation to the lab coat conditioned simul taneously wi th the metronome? Or was t he lab coat cond itioned to t he metronome, w hich was conditioned to the meat powder, which would thus be a case of second-order cond itioning? G iven the p hysiologist' s tradition of precision ( sal ivation was measured drop by drop and times recorded), such problems becam e critical to an accurate interpretation of results . Pavlov and h is coworkers responded by developing automated metho d s of stimulus presentation a n d response measurement that were ingenious a n d accurate. Until Professor Skinner's elegantly simple "Skinner b ox , " the S oviet behavioral technology was the most advanced in t he world . It is perhaps indicative of Pavlov' s careful appro ach to obj ective research that none of the m aj or laws of classical con ditioning systematized by him h ave been s hown to be false-and this when the w ork was essentially completed by 1926 . Compare this to the rise and fall of a myriad of American learning theori e s . B u t even though t he empirical findings of Pavlov a n d h is m a n y coworkers h ave withstood the test of tim e , h is theoretical foun dations h ave p roven to be of little utility . This is p articularly true of his attempts to explain complex behav i or in terms of brain state s . For example, Pavlov s uggested that consciousness m ight consist of states of gen eral cortical exci tation . Unconscious learn ing, he spec ulated, might be the result of a local synthesizing are a in an excitatory state becoming surrounded by s tates of inhibition . This would cause learn ing i n that area to b e isolated from conscious ness o r to be unconscious . When t he s urro un ding area s again b ecame excited , the subconsciously formed associ ation would enter the field of con sciousness as a link seeming to have arisen spontaneously. He felt that h is experimen tal procedures would eventually demonstrate the existence of s uch localized foci of excitati on .

32

The Hzs tory of Lea rn ing Theory

As such hypotheses illustrate , Pavlov' s the ory, which was designed to ex­ plain the effects of his learning laws, was often based upon s peculations about unobservable events . Although his laws of learning remain useful in predicting behavior occurring as the result of application of his experimental p rocedures, his theory often neither explains nor predicts . Failures in predicting t he occur­ rence of a given response are explained away as the an imal's drowsiness or domination by inhibition . The appearance of unpredicted respon ses is ex­ plained as t he result of slig h t alterations of the environmen t which must have elicited the OR or d isinhibited previously inhib i ted res ponses. To be fair to Pavlov , the post hoc (after- the-fact) quality of his efforts to explain complicated p henomena s uch as complex habits and consciousness was p artly the res ult of the pressures p ut on most well-known scientists to explain and integrate their results . In Pavlov's case , these p ressures resulted in h is theory' s going far be­ yond the facts gathered from his carefully executed experiments . Consequently, his laws of learning and h is experimental procedures have con tinued to be infl uential, while his theory is today considere d prim arily of historical interest. One b eneficial effect of Pavlov' s will ingness to speculate about mind and complex behavior has been the continued i nvestigation of such p henomena within a tradition of rigoro us experimentation in the Soviet Union . Pavlov' s open- minded a ttitude towards the existence of complex co gnitive even ts was not mirrored in the the ories of the American learning theorists Watson and Guthrie to be reviewed in the next chapter. These theorists were radical in their repudiation of s uch ideas as " mind , " and t he ir efforts to be obj ective res ulted both in the development of a rigorous experimental tradition and a rej ection of the inves tigation of cognitive p henomen a . K e y Terms backward conditioning

first signal system

reductionistic

cerebral cortex

generalization (irra dia ­ tion )

reflex

classica l conditioning conditioned neurosis

generalized secon dary (condition ed) reinforcer

con ditioned (conditional) response ( reflex) (CR)

habituation

conditioned stimulus (CS)

in duction inhibitory ( - ) reflex

discrimination ( differ­ entiation)

internal inhibition

disinhibition

orienting reflex (OR)

elicit

Pavlovian c onditioning

excitatory

( + ) reflex

phobia

external inhibition

pseudoconditioning

extinction

reciproca l inhibition

respon dent con ditioning secon d signal system second -order con ditioning sensitization spontaneous recovery temp oral con ditioning trace con ditioning uncon ditioned (uncondi­ tional ) response (reflex) (UR) uncon ditioned (uncondi­ tional) stimulus ( US)

Pavlovian Conditioning

33

A nnotate d B ibliograph y

The one outstand ing source for those students wishing to read what Pavlov actually s aid about learn ing is the 1927 English translation of lectures delivered by Pavlov in the spring of 1924 to an audience of medical men and biologists a t the m ilitary medical academy in Pe trograd . This book, Conditioned refiexes (New York: Dover, 1 960), is available in paperback and also i ncludes Pavlov's revisions of some of the material p resented in those lectures in the later chapters . Students interested in Pavlov ' s life and early Soviet psychology s hould rea d B . Babkin , Pa vlov , A biogra phy (Chicag o : Un iversity o f C h icago Press, 1 949) .

A m erican Ap proaches to Contiguity Conditioning : Watson and G uthrie

Pavlov's theory was not the only contiguity approach to learn ing theory . In the United States, first J o hn Watson an d then E dwin G uthrie also believed that the " how" of learning n ew connections was related to the association of cues, and they developed theories based on this assumption tha t h ab its are formed as the result of rote repetition . B y explaining complex learning p henomena in terms of a very few basic laws, Watson and Gu thrie made substantial contributions to the historical development of the psycholo gy of learning, as we will also see by a b rief summary of a theory derived fro m their tradition (Es tes' s statistical learning theory) . The mech anical formation of habi ts thro u gh a ssociation is the core of t he contiguity theories of Watson and Guthrie . The ap peal of such contigu i ty theories may lie in their apparent simplicity and their freedom fro m residual contamin ation by concepts s uch as reward, which usually imply something about the intern al reactions of the " rewarded" organ ism . American psychology had an opportunity to develop its own contigu ity theories following Twi tmyer's p resenta tion of his results on the cond itioning of the knee j erk reflex at a meeting of the American Psychological Association in 1904 . The ind ifferent recep tion accorded Twitmyer' s work ( Hall, 1976) meant that s uch an opportunity laid dormant un til the p ioneering work of John Wa tson had a maj or impact with his 1913 publication of a "be haviorist manifesto . " Watson was largely responsible for eleva ting the idea that conditioning occurred because of contiguity mech anisms into a dominant learning theory approach . After Watson left academic psychology, this appro ach continued to be highly influential in the 1930s and early 1950s, becau se of the work of G u thrie and then his follower Este s . ,

John Broadus Watson (1878-195 8)

Few p sychologists have had such a great impact on the field in so s hort a time a s John Watson . From h i s intro duction o f the term "behaviorist" into the general p sychological vocabulary in 1 913 in his behaviorist manifesto ( " Psychology a s the Behavi orist Views I t , " 1 913) to h is abru pt resignation from J o h n s Hopkins University, Watson dominated American learn ing theory . He rece ived h is de­ gree fro m the University o f Chicago in 1 903 , a time when the University of

Watson and G u th rie

35

C h icago was dominated by a p hilosophy called "functionalism , " which was a blend of evolutionary theory and a b elief in mind as the maj or concept for un ders tanding human beings . Watson revolted again s t b o th of t hese aspects of function alism . He also a ttacked the more soph isticated mentalism a dvocated by Titchener, and labeled by h im as introspectionist. Titchener demanded that psychologists s tu dy their own thoughts (in trospect) and use the resulting re­ p orts of thoughts as their major source of data . From the viewpoint of Watson and G uthrie (and of mos t o ther behaviorists as well) , t he problem with accept­ ing as data reports of self-observation of mental events was that such data were always priva te . That is, there was no way for a second observer to check t he accuracy of the firs t observer' s report. Hence, there was no way to resolve dis­ agreements among observers . In 1 903 , Watson published a maj or study correlating the learning abili ty of rats with the degree of insulation of their nerve fibers (B olles, 1 975) , and h is research was always to focus on animals and children . With h is rej ection of mentalism and h is a dv ocacy of a comparative appro ach to research , Watson became the spokesman of those p sychologists esp ousing a mechanis tic, obj ec­ tive, environmentalist, and scient ific- soun ding viewp oint .

B e h a v ior as the Yardstick of Learn ing Watson argued that d iscoveries in p hysics and the n atural sciences had resulted fro m one fac tor only : the careful measuremen t of obj ective, physical phenom­ ena . A basic ten et of the older and more successful sciences was that for an observation to become accepted as data for science, i t must in p rinciple be repeatable . Thus, every scien tist measuring the expansion of gas un der con di­ tions of reduced p ressure would arrive a t similar computations, a ssuming tha t they took their measurements in the same way, a n d s o on . Watson suggested that mental p henomena simply could not mee t these criteria for objective data . Without obj ective d ata, p sychology could never b ecome a true science . There­ fore, in the i n teres t of developing a science of p sychology, measuremen ts of mind must b e abandoned . Behavior, on the o ther hand, could b e q uantified and measured obj ectively. Several observers watching a rat run a maze would arrive at similar calculations of i ts runn in g speed; hence, behavior p rovi ded tru e , scientifically acceptable d a ta . Watson also believed that b ehavior was the p roduct of t he brain and m u s t follow similar principles in mammals h aving somewhat similar b rains . For b oth rat and man, t he basic unit of learning was t he habit, and the habit was ac­ q uired as the result of the s trengthening of a neural link b e tween a s timulus and a respon se. B y the publication of his 1 914 book, Beha vior: An In tro duc tion to Co mpara tive Psychology, Wa tson had gone so far as to deny the existence of mind and all men talistic p henomena. Feelings, i m ages, t hought, and all such experi­ ences he considered to be nothing more than s mall motions of, say, the m uscles of the throat and voice b ox for tho u gh t . S o Watson, in a sense, m ade up h is windpipe tha t he had no mind ! He w a s the extreme peripheral connection ist; that is, he felt s timuli were connected wi th p eripheral m uscle responses rat her than wi th central thoughts in t he brain .

36

The H istory of L ea rn ing Theory

Although such extreme p ositions were rej ected in psychology after Watson left the field , some exp erimental support is ava ilable for the idea of muscle p o tentials occurring at the time though ts are experienced . McGui gan (1973) found that when a p sychotic p a tient thought he was hearing voices, simulta­ neous muscle-action potentials were measurable in his throat! Many recent Russian researchers (O'Connor, 1966) see muscle move ment as part of early thought. Such a position also appears in extreme form i n m any current " p op therapies," such as Rolfing, which maintains that negative emotional experi­ ences are " remembered" in patterns of muscle tension and that the thoughts which accompanied the unfortunate events will be b ro u ght back by deep mas­ s age of the tense muscle groups (Keen , 1970) . For Watson , learning of skills was a matter of linking mu scular responses . These links then formed the obj ective events that i n tervened between envi ron­ mental s timuli and response s . Thus, the re ason a rat was able to run a maze correctly after many trials was that it had acq uired a pattern of muscular re­ sponses corresponding to the various turns, stops, and places to run forward i n the maze . B olles (1 975) reports a conversation with an acq uaintance of Watson' s which might explain Watson' s reliance on kinesthe tic ( muscle p osition sense) cues . When H . L angfeld asked Watson how he could deny the subj ective experi­ ence of dreaming, Watson had asked , "Wh at is a dream?" Watson himself may h ave lacked visu al imagery, or the abili ty to remembe r d reams, leading him to suggest that muscle sen sations are the basis for thou ght and memory . It is, of course, ironic that Watson, i n his desire to avo id unobservab le mentalistic con­ cepts, was force d to speculate on the role of a type of inner behavior which , in his time, was equally unavailable to direct observation . Watson was much i n1 pressed by the condi tioning model developed by Bekhterev which stressed use of USs such as shock to elici t skeletal muscle response s . Bekhterev's philosophy was as ad amant in its rej ection of mind as Watson's . In 1914, Wa tson was elected president of the American Psychological Association and rep orted on the reality of classical (Russian) condi tioning in h is presidential add ress . The work of Bekhterev and later Pavlov (Watson , 1916) s trongly i nfl uenced his a ttempts to explain the mecha n isms of habit formation .

Ho1v Do We Learn ? Wa tson 's Ans1uer First, Wa tson considered all learn i ng as condi ti oning of habits . Second , he thought that only two basic laws are necessary to descri be the conditions under which bonds would form between stimuli and response s . His first law states that the s trength of a bond depended upon the number of pairings (association s) of stimulus and response ( the law of frequency) . The second law s tates that the response occurri ng j us t after a given s tim ulus is most l i kely to be paired wi th that s timulus ( the law o f recency) . Su ccessful condi tioning resulted from fre­ q uent pairi ngs of cues, or responses and cues . The pairing, moreover, would be most effective if both were presented near the s ame time . While Watson encoun­ tered some failures i n his attem pts to replicate Russian research , he did succeed in condition ing both increased heart rate and leg wi thdrawal to a tone p resented before shock . In his writings, however, Wa tson made no d is ti nction between the types of responses . This simplistic approach to theory b uilding continued to

Wa tson and G u th rie

37

characterize Watson' s work ( i n marked contra s t to the elaborate detail presen ted by Pavlov) . Watson's e a r l y t h e o ry rested o n two l aws of l ea r n i n g , t h e l aws of f re q u en cy a n d recency. T h e stre n g t h of a g iv e n S- R b o n d , h e b e l i eved , is d e pe n d e n t u po n b o t h t y p e s of effects.

A Con tiguity Expla na tion of the Effects of Appa ren t Reinforce1nent Watson dismissed the effects of reinforcement ( i n particular, his rival Thorndike's "law of effect") by s tating tha t a successful act be � omes both the most recent and the most frequent response . Therefore, reward as an explana ­ tory concept i s superfluous . For example, a c a t trying t o escape from a puzzle box emits a variety of response s . One of these responses finally allows the cat to escape from the p uzzle box and the cues associated with that box. Only the s uccessful response is p aired with end ing the cat' s exposure to the puzzle box cues, and so this response is always the one most recently paired wi th those cues once the trial has ended . Because a cat who h as successfully escaped a p uzzle box is no longer exposed to the p uzzle box cues (at least not until the next learn ing trial) , the connection between those cues and the s uccessful response is protected from i nterference . All the connections b e tween p uzzle box cues and earlier responses, on the o ther hand, are interfered wi th by following res ponses (which b ecome the most recent resp onses until they, in tum , are followed by later responses) . Since at least all reasonably sm art cats eventually emit a suc­ cessful response and escape, the successful response is always the last one emit­ ted i n the presence of the b ox and it rapidly beco mes mo st s trongly connected to the puzzle box cue s . This results in the successful resp onses becoming i ncreas­ i ngly probable i n the presence of those cues; thus, this response also becomes more frequent than any o ther response . As it becomes most frequent, this re­ sponse becomes so s trongly connected with b e ing in a puzzle box that the cat will immediately em i t this respon se as soon as it is placed in the box . As you can see, this explanation of the cat' s demonstrated ability to improve as a puzzle box escape artist is based entirely on frequency-recency considerations rather than s atisfaction or drive reduction . In the final years of his academic career, Watson appeared to realize the inadequacies of his simple model . In a book published in 1919, he down played the role of frequency as a maj or explanatory concept and moved more in the direction of the p hysiological and behavioral concepts originated by Bekhterev and Pavlov ( Hill, 1971 ) . B y the time of h is famo us experiment wi th little Albert, conducted with h is stu d en t Rayner (Watson and Rayner, 1920) , Watson was ready to explain most be havior in the carefully worked -o u t language of classical conditioning.

The Case of "Little Albert" In this experiment w i th a healthy nine-m onth-old boy, Albert, who was en­ rolled at a day-care center, a white rat was used as the CS ( thereby un iting Wat­ son's favorite subj ects) which originally elic ited Albert's orienting reflex and

38

fh c H istory of L ea rn ing Theory

reaching . * When Albert reached for the rat, the US of a soun d made by hitting an iron rail with a hammer (see Fi gure 2 . 1) was sounded , provoki ng the startle reflex and crying ( the UR) . After six trials, the sight of the rat alone (the CS) was enough to elicit cryi ng and avo idance. This effect generalized to white rabbi ts, dogs, and animal furs . While Wa tson and Rayn er discussed several cond ition ing p rocedures to remove the cond itioned phobia, the removal of Albert from the center by his mother p reven ted any of them from be ing tes ted . At the en d of the article, Watson suggested : The Freud ians twen ty years from now, unless the ir hypotheses ch an ge, when they come to analyze Albert' s fear of a seal s k i n coat-assum in g that he comes to analysis a t that age-will p robably tease fro m h i m the reci tal of a d ream wh ich upon their analysis will show that Albert at three years of age a ttempted to play w i th the pubic hair of the mo ther and was scolded vi olen tly for i t . ( We are by no means d enying that th is might i n some o th er case con d i tion i t . ) I f the analyst has sufficiently pre pared Albert to accept s uch a dream when found as an explana­ t ion of his avo i d i n g tendencies, and if the analyst has the authori ty and p erson­ ali ty to put it over, Albert may be fully convi nced tha t the dream was a true revealer of the factors w hich b rought about the fear. [ Wa tson and Rayner, 1 920, p. 1 4 ]

Wa tson's Positions 011 Major Iss ues Na t u re/n u rture Watson's emphatic commitment to rad ical env1ronn1entalism is shown in the fol lowing passage: G ive me a dozen healthy i n fan ts, well - formed , and n1y own specified world to bring them up in an d I ' ll guarantee to take any one at randon1 and train h im to become any type of specialist I m ight selec t-doctor, l awyer, artis t , merchant­ chief and , yes, even beggar- man and th ief, regardless of h i s talents, penchan ts, tendencies, abil ities, vocations, and the race of h is ancestors . [Wa tson, 1 924, p .

82 ]

The ho1v of lea rn ing

Wa tson fi rst believed that the pri nci ples of frequency a n d recency are sufficient to explain condition ing . Beca use a successful act is both most frequent and mos t recent, i t becomes the n1ost l i kely to be repea ted in similar circums tances . He felt the sa tisfier a n d annoyer systen1 of Thorndike (see Cha pter 3) to be contan1 i nated by residual subj ectivity . I n later forn1 tilations, he adopted the Pavlovi an position (H ilgard and Bower, 1 975 ) .

The 1vlz a t of lea r11 i11g

Accord ing to Wa tson , bon ds be tween observable stimuli and observable or potentially observable res ponses are the un it of learn­ ing. What is learned was a habit or a condi tioned reflex consisting of l i n ked n1 uscl e responses .

Co11 ti11 11 ity /11011co1 1 ti11 u ity ,

of a 11i111a l da ta , a nd de ten11 i11is111

Leaming occurs thro ugh a n accun1 tilation of habit s trength . Apparen t demons trations of use

* One reason Watson may have p re ferred i n fants and ra ts a s s u bjects was their i nab i l i ty to i ntrod uce verbal conta m i n a tion i n to the testing situation. One assu m e s that ad ults would persist i n cla i m ing they had i m a ges and thoughts a n d that their verbal respon ses would offend Wa tson ' s need for objectivi ty .

Watson and G u th rie

39

Figu re 2 . 1 Wa tson sn eaking up on unsu specting "little Albert, " who is hap pily playing with a wh ite ra t . In Wa tson's hand is a h a m m er wh ich h e is abou t to s trike u pon a suspended steel bar "fo u r feet long a n d ! inch in dia m eter, " thereby begi n n ing th e process of making " lit­ tle Albert" the firs t h u m a n with a n experimental n e u rosis in the form of a phobic fear of wh ite furry objects . Watson 's assis ta n t, Rosalie Ray ner, is dis tracting " little Albert" from Wa tson's approach .

i nsight reflect nothing b ut very rapid accumul ations of habit s trength or the end result of tiny intention movements, creating movement-pro duced s timuli that elicit the final sudden overt respon se . Thus, learning is always continuo us . According to Watson, d ata collected from animals applies to human behavior, a nd behavior is determined by the environment.

Perspective In the case of "'little Albert," Wa tson has provided a model for how a fear might be acquired . Although he suggeste d a treatmen t for removing the fear, he d i d not have an opportunity t o apply i t . This was firs t done b y M a ry Cover Jones (1924) , a student who worked with Watson after he left J o hn s Hopkins . She compare d several metho ds, i ncluding Watson ' s proposed plan for direct cond i ­ tioning of the fear s timulus t o a positive s timulus . Using food as the positive stimulus, she was able to remove a fear of rabbits by g radually mov i ng t he

40

TJze HistonJ of Lea rn ing Theory

rabbit clo ser and closer to her s ubj ect while he ate . Eventually, her subj ect had overcome h is " rabbit phobia" to such an exten t that he was able to handle the an imal. Prefiguring B andura' s ( C hapter 9) technique of modeling, she was also successful in removing such fears by a social imitation tech n ique in which a fea rless subj ect h an dled the an imal in the p resence of the subj ect suffering fro m the fear. B y p rod u c i n g a p h o b i a ( ext re m e fea r) of w h i te f u r ry o bjects i n l i tt l e A l b ert t h ro u g h c l ass i c a l c on d i t i o n i n g , Watson a n d Ray n er were a b l e to d e m o n st rate t h at t h e l aws of l e a r n i n g can a l so a c co u n t for at l eas t s o m e f o r m s of pat h o l og­ ical b e h av i o r .

One reason that Watson was not the first to use techniques that we tod ay call behavioral modification was that he was forced to leave the halls of academia in 1920 because of h is affair wi th his laboratory assistant, Rosalie Rayner. For this affair he may have suffered less than the field of psychology d i d . He divorced his wife, married Rosalie, went to work for an a dvertising agency 0 . Walter Thompson) , and became wealthy. He published one maj o r b ook in 1924 and left h is mark on the public with his slogan, "Lucky Strike G reen h as gone to war"­ referring to the change in color of Lucky Strike cigarette p ackages from green to white to s ave green dye for the war effort in World War II (Schultz, 1 969) . One assumes that this slogan was an attempt to condi tio n smoking Lucky Strikes thro ugh contigu ity of the b rand name to patriotic expressions . With Watson out of academic psychology, the d efense of the con tigui ty perspective in learning theory fell into the capable han d s of E dwin Guth ri e . Guthrie's theory was de­ veloped in more detail than Watson's, and his id eas were more influen tial in shaping the future developmen t of learning theory . Edwin R . G uthrie (1886-1959)

O rigi nally trained as a p hilosopher, G uthrie became a p sychologist when he was convi nced that the experimental method might be u sed to approach many of the tradi tional pro blems concerning the nature of n1a n . He was strongly influ­ enced by the argumen t of the philosopher Singer that n1any of the problems of the mind co uld be transla ted in to behavi or (Guthrie, 1 959) , and he became a behaviorist. His firs t text in 1 92 1 was largely Wa tsonian in tone. Simple behav­ ior was a matter of sim ple S-R connections, and complex behavi or was a mul­ titude of simple S-R connections . Like Wa tson, he saw the b rain as a tab u la rasa and minimized innate organization and motiva tional principles (Bolles, 1 975) . Also like Watson , G u thrie used the word "condi tioning" to cover almost all forms of learning, and he maxi mized the role of environmental factors in shap­ ing the nature of an adult human . By 1 935, however, he had moved from a res tatemen t of an orthodox Wa tsonian position to the development of an eq ually mechanistic but highly individ ual theory of learning.

A S ingle La7.u of Lea rn ing In contrast to the highly complex system developed by Pavlov or Watson ' s two-law system o f learn ing (frequency a n d recency) , Guthrie produced the ul-

Watson a n d G u th rie

41

timate in simplicity in theory building: a theory with a single l aw describing t he necessary and s ufficient con d itions for learning, which he l abeled the law o f contiguity. N o lists of laws, no rewards, only stimuli and movements b on d ed into combinations, as follows : " A combination of stimuli which h as accom­ p an ied a movement will on i ts reoccurrence tend to be followed by that move­ ment" (Guthrie, 1935, p . 26) . To further the impression of exaggerated simplic­ i ty, t he law had only one add i tional p os tula te : "A stimulu s p attern gains i ts full associative s trength on the basis of its first p airing with a response" ( Gu thrie, 1942, p . 30) . G u thrie suggested no t only that the p ri nc iple of recency alone is enough to account for learn ing but also that all learning is one-trial learning. Thus, w hatever was d one last in the presence of a given s timulus combination will be d one agai n when the stimulus combination next occurs . G u t h r i e p ro posed a t heory of lea r n i n g w i t h t w o basic p r i n c i p l e s : ( 1 ) t h i n g s w h i c h o c c u r toget her w i l l t e n d t o b e asso c i ated ( t h e l aw o f co n t i g u i ty) , a n d (2) a l l s u c h asso c i a t i o n s o cc u r i n a si n g l e t ri a l .

Though t o advocate so simple a theory might a t firs t i nspection appear unwise , G uthrie was able t o defend h is work against a w i d e range of o bj ections without adding further laws, and on a logical rather than experim en tal basis . :For exam­ ple, we know that most learning appears to be acq uired gradually rather than in the abrupt " one- trial" fashion s pecified by Guthrie's " one-trial learning" postu­ late . G uthrie, however, evaded this obj ection by redefining " stimulus . " A situa­ tion may seem like a single cue, b ut in reality i t is composed of a m ass of s timuli that changes fro m moment to inomen t . Millions of nerve fib ers carry informa­ tion reporting on a world w hich alters as the organism moves about . The kinesthetic feedback on muscle condition is a function of millions of receptors rep orting millions of small movements within muscle g ro up s . Hence, what seems a single response is i n reality a mass of resp onses, and what seems a single s timulus is a myriad of stimuli . E ach of these elements can be combined with each other, and i t is these tiny bonds that are formed in single trial s . In each trial, many of these small res p onses are b onded to many of the s timul i . The gradual acquisition curve we see is the ultimate result of the gradu al increase in appropriate bond s and the gradu al elimination of inapp ro priate bonds . Thus, G u thrie would say that imp rovement in an act refers to the outcome of learning rather than to the process of learn ing . Errors are learning that does not fit with m astery of the final act, and learning is the p rocess by which all cues are eventu­ ally bonded to acceptable behavior. Improvemen t, therefore, e quals the learning of more and more correct movements . Examples might b e skills (which are the same as acts, according to Gu thrie) such as touch typing, in which more and more correct key s trikes ( movemen ts) g radually take over fro m an initial p attern of inaccurate and awkward attempts to s trike the correct Keys without look­ ing at them . Furtherm ore, when you type highly practiced word s, e ach letter of the word is accompanied by specific muscle sensations ( movement- p roduced stimuli) which signal you that it is time to strike t he next letter . The next m ove after a

42

The History of Learning Theory

specific movement- pro d uced s timulus is the res ponse which has become (through contiguity) cond i tioned to it. This resp onse in tum produces new cues w hich are conditioned to the next response , and so on . fur example, it is difficul t not to type the letter u j us t after typing the letter q because of the freq uent association of these two letters i n the q u sequence . This chaining of cues pro­ duced by your own movements to further muscle movem ents is a maj or factor in linking the separate movements i n to the completed act. Movemen t-produced stim uli lin ked to i ncorrect movements do not get conditioned to further typ i n g responses because you p ause a n d emi t o ther behaviors, such a s erasin g the error. O nly typing movements that are acceptable to you lead to s timuli that i n turn get linked to further typing. Self-generated stimuli were a key part of Guthrie's theory, and this type of mediating mechanism was used i n the theories which came after G u thrie . Another obj ection to Guthrie's theory is that a n im als fail to learn to respond u nless they are rewarded or escape aversive conse quences (such as shock) for doing so . G u thrie defends h is theory that "con tiguity is the only mechan ism of learn ing" by explain i n g that reward is a source of s timuli w hich serves to rel a te o ther groups of cues . In addition , reward p rotects a collection of S-R b onds from " unlearnin g" by makin g them the last thi n gs to h appen j us t b efore the reward changes the stimulus situati on (Guthrie and Horton, 1 946) . This is the same mechanism used i n Watson's theory . Drives and their reduction thro ugh appropriate actions are also seen as n o t necessary for learning to occur. This i s i n marked con tra s t t o H ull's reinforce­ ment theory, to be presented in the next chapter. Drives, however, are seen as often contributing to learnin g . This is because most drives serve as sources of maintaining stimuli . Yo u know that when you are hun gry, you may experience s tomach con traction s and enhanced sensitivity to food- rela ted stimul i . The stimuli associated with a drive state are seen as provi d i n g a u nifying element to the series of stimuli and responses which lead to the fin al elimination of the stimuli associated with that drive state . The cues accompanyi n g hunger become linked to a set of S-R bonds which connect cues an d movemen ts that have led in the past to food rewards . The food rewards stop the hun ger cues and thus in terrupt the co mbination of maintain in g stimuli and movement-pro duced stimuli . The rat presses the bar in the Skinner box when hungry because the last thin g he did when he was hung ry in that situation was to press the b ar. G e ttin g the food reduces the h u nger cues so tha t the s timulus situa tion faced b y the rat becomes differen t and is no longer the one bonded to bar pressin g . Therefore, the satiated rat stops pressin g . Essentially, the role of reward is to pro tect those responses made j us t before the reward from being connected to responses o ther than those pro ducing the reward (Hilgard and Bower, 1975) . Experimen tal ex­ tinction results in a red uction in rates of formerly rewarded responses because the subj ect is no longer exposed to the changes in stimuli associated wi th drive reduction . This res ults in new resp onses now being produced in the presence of the cues that were origi nally linked to movemen ts that led to reward . Without re inforcemen t to protect the sequence of resp onses that once had been re­ warded, increasing n umbers of the new competing responses are linked to

Wa tson and G u th rie

43

situation al cues, and the formerly rewarded sequence gradually vanis he s . This is called associative inhibition, and it is also the b asis for forgetti n g . Forgettin g occurs because of interference , which appears i n the form of new, competing learning. G u thrie, like Tolman ( i n Chapter 5), believed that d rive states p roduce anticipatory responses. These anticip atory s tates consist o f states of actual m us ­ cular readiness to do the behavior formerly emitted i n the presence of the reward which reduced the drive state in the past ( Guthrie, 1935) . These states are p hysical-they are not t he cogn itions of Tolman' s theory . The G u thrie position on reward can b e summarized as a position o f " s t im ulus change a s reward , " wi th i nternal stimuli and respon ses ( acting as s timuli) being changed b y reward . If the effect of reward is to remove the animal from a situat ion and hence to prese rve the bonds t hat were formed in that situation, how d i d G u thrie explai n the effects of p un ishment? Again, h e stated that the animal repeats w hat it h a s d one l a s t in a situation . The aversive stimuli act to pro duce general tension a n d restlessness as well a s movement that eventually removes the subject from the pain. G ut hrie said the animal learns to repeat i ts actions leading up to the pain, as well a s those occurring j us t after the punis hment (Guthrie, 1 935) . This led to his p rediction of the followi n g results, which seem to go against common sense : Ra ts were trained to run i n a long alley . When they almost reached the goal box, their hind p aws were shocked . After t h is experience, t he rats res p onded to the cue of an alley, in which they p revi ously j umped forward a t its end (because of the shock to the ir rear p aws) by running forward faster when they again started up that alley . This result seems to contradict the commonsense prediction that the rats would b ecome afraid to run toward the end of the alley w here they had been shocked . Thus, p un ishmen t is effective or not effective, from the punisher' s point of view, depending upon what i t causes the p un ished organism to do . Pun ishment is effective only when i t results i n a n ew response to the old cues . Punishment changes unwanted habits when it elicits new behavior i ncompati­ ble with the pun ished behavior. Again, learn ing is the result of a change in stimulus con d ition s . Movements condi tioned to aversive stim uli (which are the source of maintaining s timuli) are those that get the s ubj ect away from the stimuli or the stimuli away from the subj ect ( Guthrie, 1 935) . G u t h r i e e x p l a i n ed p he n o m en a s u c h as t h e effec ts of r ewa rd a n d d ri v e states, a n d t he i r red u ct i o n , p u n is h m en t , a n d e x p er i m en t a l e xt i n ct i on i n t e r m s of c o n ti g u i ty p ri n c i p l es r e l at e d t o c h a n g es i n sti m u l u s c on d i t i o n s rat h e r t h an i n t e r m s of r e i n f o rc e m en t .

Applica tions The results j ust discussed are congruent wi th Guthrie' s general s uggestions on p un ishment. G u thrie stated tha t for punishment to be effective, it must cause competing response s to occur i n the presence of cues for the unwanted b ehav­ ior. As an example, G u thrie (1935) s uggested the following treatment for a ch ild who comes home from school and fails to h ang up h is coat: The child should be

44

The History of Learn ing Th eory

told to put his coat on again and should then be sent back outside to repeat the entire sequence leading into the house . Upon the ch ild's reentry, he mus t hang up the coat. Thus, the cues associated with the entry should be bonded to the response of hanging up the coa t . In this example, as in the ap plications to follow, t he emphasis is on connecting specific stimuli wi th specific responses . The punishment of going outside again works b ecause the child is then forced to connect the new b ehavior of hanging up the coat wi th the s timuli (those asso­ ciated with the house and the muscle movements involved in enteri n g the house) that were formerly paired wi th not hanging up the coat. This also illus­ trates ano ther feature of G u thrie's theory : Because connec tions are between sp ecific stimuli and specific resp onses, transfer of training would be expected to occur only to the extent that old stimuli are present in the new situation s . In the example of the child and the coat, it would be exp ected that " coat hanging-up" might not occur if the ch ild were entering someone else's house . Such a method of breaking a bad habit is an example of Guthrie's incompat­ ible response metho d . G uthrie also sugges ted two o ther methods for breaking habits, t he fatigue method a nd the threshold metho d . The fatigue method con­ sists of allowing an unwanted act to be repeated un til i t fatig ues and "not respond ing" becomes associated with the cues tha t formerly elicited the un­ wanted response . An example would be the breaking of a bucking bronco by having the rider remain on his back until the horse is too exhaus ted to buck . The s timuli associated wi th the rider are now assumed to be connected to the re­ sponses of " not bucking . " Ayllon (1 963) successfully used a related method (which he called the method of stimulus satiation) to elim inate towel hoarding by an institutionalized psycho tic woma n . Instead of retrieving the ward ' s sup­ ply of towels fro m the woman' s room, a nurse would enter her room at random intervals throughout the day and hand her a towel wi thout commen t . The woman would hoard the towels handed to her. By the end of the th ird week o f treatment, s he was being given an average of 60 towels daily . When the number of towels kept in her room reached the 625 mark , the patient began taking them out. Before this treatment, the average num ber of towels foun d in her room had been 20. After treatment, only an average of 1 . 5 towels were to be foun d . The third ( threshold) method involves intro ducing the cues which normally elicit the unwanted behavior at such low intensity that no s uch behavior occurs . During this time, o ther responses beco me associa ted wi th these cues . G radu­ ally, then , the intensity of the s timulus is inc reased , taking care that it is below the " threshold" of the unwanted response . Even tually, the subject can be ex­ posed to the full intensity of what had been cues for the undesired behavior wi thout emi tting that behavior. For instance, a bronco could also be broken by first putting a very light blanket on his back, then gradually adding more bla n­ kets and a saddle, and fi nally adding the rider. Wh ile the natural response to the weight of the rider would have been to buck, the weight of a light blanket would not be a strong enough cue to elici t bucking. As the horse gradually gets " used to" the cues of weight on his back, even the s timulus of the rider will be associated wi th "not bucking . " This method is very similar to the tech nique of systematic desensitiza tion , which is an important clinical tool of behaviorally

Wa tson and G u th rie

45

orien ted therapists . In this technique ( d iscussed in detail in Chapter 6), a h ier­ archy of fear cues is presented (beginning with very weak fear cues) in the pres­ ence of cues for the incompatible response of relaxing. G u thrie (1938) suggested that the threshold method is a common feature of everyday human interaction s . For example, a mother wishing to send her d aughter to a n expensive sch o ol might begin by casually mention ing it to her h usb a nd . Initially, discussion about the school is kept at a level that is low keyed enough to not provoke a negative reactio n . When the issue is finally raised i n a direct manner, the father is used to the idea and no violent reaction over the anticipated expenses occurs . In comparing his three methods, G uthrie concluded that all of them i nvolve finding the cues w hich elicit the unwanted h ab i t and then making sure that these cues become s timuli for competing resp onses . All methods are seen as having equivalent res ults ( Guthrie, 1938) . G u t h r i e p ro posed t h ree m et h od s for e l i m i n ati n g bad h a b i ts , a l l based on h i s c e n t ra l ass u m pt i o n t h at b e h av i or i s c o n t ro l l ed b y s ti m u l i . These a re t h e m e t h ­ o d s o f : ( 1 ) i n c o m pati b l e response, (2) fati g u e , a n d (3) t h re s ho l d .

G u thrie's Positions on Major Issu es Natu re /n u rtu re Guthrie, like Watson, was a strong environmentalist: When a man hammers h is thumb we do not explain h is d anci ng movements and vocalization in terms of an a ro used "ego" or aroused "lib i d o , " nor do we say that h is activ ities are an expression of the self- p reservation instinct . It is sim ply that m en who hammer their thum b s usually becom e very active for a time . . . The p roblem of m otives arises when i t is necessa ry to exp lain how b ehav ior becomes d irec ted to certain ends, and this is a problem of learn ing . . . [ G u th rie, 1938 , p . 96]

In this example, t he behavior is seen as environmen tally dependent rather than due to instincts or inherited motive s . The direct i on of behavior is explicitly defined as the res ult of learn ing in the environment .

The how of learn ing

G u thrie was the p urest of the contiguity theorists :

We shall have a much better insig h t into the uses of p un ishment and reward if we a nalyze their effects in terms of association and realize that p un ishm en t is effective only through its a ssociation . . . [ Guthrie, 1952, p. 132]

The zuh a t of learn ing

The association of individual muscle movements with individual stimuli is the basic unit of learnin g . Complex habits represent the net sum of many of these b asic units .

Con tin u ity!noncon tin u ity, use of a n in1 al da ta , a nd de terminism

Leaming always takes place on the first p airing o f a single stimulus and a single response . Skills are built up slowly, however. Guthrie explaine d : Learni ng occurs normally i n o n e associative episo d e . . . . A skill i s not a simple h ab it, but a l a rge collection of h ab i ts that ach ieve a certain result in many and varied circumstance s . [Gut hrie, 1942 , p. 59]

46

The History of Len r11i11g Th eory

G uthrie was a typical behavi oris t in feel ing free to generalize animal data to humans, and he saw be havior as determ ined by even ts in the environment.

Perspective Central to Gu thrie's theory was t he followi ng idea : B ecause we tend to repeat movemen ts when reexposed to the cues associated w i th those movemen ts in the past, envi ronments with unchanging cues should produce s tereotyped move­ ments. Guthrie and Horton (1946) photographed the responses of cats escapi ng fro m puzzle boxes and found that each cat d i d indeed develop a s tereotyped pattern of escape move men ts . Gu thrie would argue that the reason these responses a re s tereotyped is that only t he last response ( the successful one) the cat made before escaping the box was protected from in terference. A d i rect test of the ass u m ption that the last response made in a situation is the only one condi tioned to the cues associated wi th that situation was performed by Vo eks ( 1 948) . She foun d that 56 of her 57 h uman subj ects working at punchboard and raised - reli ef finger mazes per­ formed in ways consisten t with the prediction that the last response made would be the one made again when the subj ect was confron ted w i th the same puzzle . This was true even tho ugh o ther responses had been made more frequen tly. Voeks (1954) also tested Guth rie' s prediction tha t stimulu s - response connections were made in all- or- none fash ion , using the human eye-blink response . Half of the subj ects gave condi tioned eyelid responses on every tri al after their first CR, and few errors were made by the other subj ects . This showed tha t, at least for most subj ects, the CRs were acq uired in a single trial, j u s t as Guthrie predicted . Another cen tral assumption of Guthrie's the ory is tha t reward i n the form of drive reduction is not essential for learn ing to occur . This assumption has been supported by a s tudy conducted by Sheffield and Roby (1950) in which rats learned to lick a water tube for a nonnu tritive sweet stimulus ( saccha rine solu­ tion) . As sacch a rin has no caloric value, no b i olo gical hunger drive is reduced and s tim ulus fac tors alone seen1 to accoun t for the learn ing. In re trospect, Guthrie n1 ade fou r im portan t lastin g con tri butions : The firs t contri bution was forcing psychologists to examine n1 ore extensively than before the role of stimuli in determ ining beh avior and learni ng. The second was ex­ tending t he lifetime of the con tigui ty perspective and s howing a need for a reexa mination of the role of rein forcen1ent by stud ies of the typ e j us t describe d , forcing the rei nforce1n en t-con nection is ts in to 111 ore sop h isticated theorizing . The th ird was the develo p 111ent of the concept of n1oven1 ent- p ro d u ced sti111 u l i . Th is concept has been incorpora ted in n1odified fonn into both H ull's a n d Ski n ­ ner's ex planations o f how a chain of behavior can be held toge ther u n til the orga nisn1 is fi nally in position to n1a ke the tern1 i nal res ponse . The fo u rt h follows from the p robabil istic na tu re of G u th rie' s theory. Beca use G u th rie s a w lea rni ng as occu rring thro ugh the "coll isions" of cues th a t h a p p ened to be in con tigui ty to each other, he fel t that the o utcorne of any given lea rning trial is p a rtly d u e to ch ance a n d hence cannot be p recisely p red icte d . Wh at can be p redicted is the average outcome of n1any trials , and in this sense Guthrie's theory is a statisti­ cal theory . This made his theory an ideal starting point for the d evelo pn1 en t o f a ma thematical model of cond ition ing. A s w e shall see i n Part 2,

Wa tson and G u th rie

47

mathematical-computer model app ro aches t o learn in g have become increas­ ingly important thro u gh the information-processin g school of learning theories . Because G u thrie' s ideas lent themselves to q uantification by William Kaye Estes, G uthrie' s infl uence has been extended to more modem approaches to learnin g . You may now wish t o take a b rief view o f Estes's statis tical version o f Guthrie's theory . O PTIONAL S ECTION Wil liam Kaye Estes (1919-

)

Even though William Kaye E stes obtained h is P h . D . in 1943 from the University of M innesota with Skinner as h is thesis d irector, his theory was p rimarily influ­ enced by the ideas of G u thrie . Estes became a p rofessor at R ockefeller University in 1968 and has continued to develop his theory (Sa hakian , 1976) . In using several of the key concepts o f G uthrie's theory in the construction o f his o wn stimulus sampling theory, E stes had to make several specific assumption s . We will now review the core assumptions o f E s tes's model and see how they lead to p redictions o f b asic learn ing phenomena . As you will see, G u thrie's theory, when developed and "p inned down" to specifics, is m uch more complex than it appears on first reading .

Ass u m p tion

1

All learn ing situations are composed of a large but fini te n umber of stimulus elements. All t he stimuli physically present for any one learning trial are labeled S . Stim uli can be inside (as in t he case of movement­ p roduced stimuli) or outside the orga n ism . 2

All responses are classified as e i ther " ri ght" (labeled A i) or "wrong" (labeled A2) . When E s tes referred to resp onses, he was talking abo u t acts in G u thrie' s terms, n o t small muscle movemen ts ( Hill , 1 977) .

Ass umption

Assu 1nption 3 All elements in S become conditioned ( or attached) to either A i or A 2• That is, all cues b ecome associated through contiguity with either " right" (leading to a successfully completed act) or " wron g" (not leading to a s uccessfully completed act) responses .

Ass u m p tion

4

Ass u m p tion

5

The learner only actually experiences a small p rop ortion of the elements ( cues) i n S on any given trial . At tention is limited . The p roportion of elements sampled p er trial out of all the s timuli p oten tially available is a constant labeled the ta ( 8) . The s ample of cues noticed by the learner on any given trial is assumed to retu rn to S after that tri al . In other words, j us t because you notice a group o f p articular cues o n a given trial d oesn' t mean that you will notice all of those cues on the n ext trial . The cues you notice on a trial are an independent s ample of all the cues you could have noticed, and each sample of cues is indepen dent of p revious samples . 6

If an A i response ends a trial, t he g ro up of cues sampled is conditioned through contiguity to A i . When t he cues are returned to S, t hey rema in attached to A 1 ( the " right" resp onse) . Therefore, the m ore s uccessful (A i) trials that occur, t he higher the proport ion of the elements in S that are con-

Ass u m p tion

48

Tlze History of Lea nzing Tlzeory

d itioned to A 1 • The more cues in S that are attache d to A 1, the h igher the probability of A 1 cues being sampled in a given tri al ; hence the h igher the p robability of future A 1 response s . This increase in the probability of making a correct response as a function of the number of "successful" trials is what Estes labeled le arning.

Assu mp tion

7

The probability of a correct response on any given tri al is predicted on the basis of the proport ions of elements conditioned to A 1 and to A 2 ("wrong responses") . If the proportion o f the total cues (elements) i n S con­ d itioned to A 1 is 75 percent, then the probabil i ty of an A 1 response is . 75 . These p robabilities shift as successful trials condition elements to A 1 and un successful trials cond ition elements to A 2 . The state of the learning system con tinues to change until either almost all of the elements become cond itioned to A 1 (com­ pleted learning) or to A 2 (extinction) . As learn ing progresses, the number of elements available to become newly conditioned to A 1 declines . Thus, this model predicts a negatively accelerated learning curve . That is, learning is usually rapid at first, but considerable time is required for the last errors to stop occur­ ring ( in Hergenhahn, 1 976) .

E s tes's theory can acco un t for many of the b asic p henomena of learn ing . As we have d iscussed, learn ing is seen as increased A 1�cue bonds . Since d uring extinction the trial us ually end s with the subj ect' s do ing something other than A 1 , the cues gradually beco me reconditioned to A2 responses. Generalization is handled in a manner very similar to Thorndi ke' s treatment of it. New situations are seen as having elements in common with situations in which condition ing has prev iously occurred . The extent of generalization is dependent upon the number of stimulus elements the two situ a tions h ave in common (Estes, 1 959) . With add itional assumptions, many addi tional phenomena of learn ing can be predicted or descri be d . The brief d iscussion o f Estes' s mathematical extension o f Guthrie's theory should be suffici ent to in troduce yo u to the basic logic of trying to make learning theory more precise thro ugh application of numerical concept s . As a gradu ate s tudent, the author was once assigned the j ob of predicting various learning outco mes when given s pecific values of the pro portion of cues attached to cor­ rect responses (A 1 , and so on) . Carryi ng out the calcula tions re q uired by Estes' s form ulas gave a value for the number of trials to learn ing at the 90 percent accuracy level and for other q uantities that c an be derive d fro m the data we collected in studies of real rats . Although Estes's theory uses a minin1um number of variables and derives these more from classical statis tical theory than from biology, the second theory in the next chapter ( Hull) represents a more am bitious appro ach to the q uantifi ­ ca tion o f learn ing theory . Estes's model i s l imited in scope, b ut Hull attempts to pred ict the full range of learn ing phenomena . H ull also uses many more vari­ ables and relates them to general events occurring within his learn ing or­ ganisms . One reason Es tes was able to lim it the number of variables in his theory is because, by focusing on stimuli and the ir relationships, he had less

Wa tson and G u th rie

49

need for spec ulation about internal sta tes . This made it easier for him to retain G u thrie' s emp h asis on explaining learning through a few basic principles . For the reinforcement theorists ( to be reviewed in the next ch apter) , mo tivational variables as well as environmental events must be considered . Th is factor co m­ plicates their theories, compared to contigu i ty theories . Chapter Perspective

John Watson introduced the term "behaviorism" and the contigui ty connec­ tionist viewpo in t i nto American psychology . Before leaving academic psychol­ ogy, he abandoned h is laws of frequency and recency in favor of the laws of classical conditioning developed by Pavlov . His concept of muscle-produced cues and the development of an American contiguity conditioning school of p sychology were continued by Guthri e . Guthrie reduced Watson ' s two laws of learning to one-the law of contiguity and a postulate which stated that bonds b e tween individual stimuli and responses were formed i n one trial. G u thrie also further developed Watson's concept of muscle movement cues into his theory of movemen t-produced stimuli . Because Guthrie' s theory was probabilistic, Estes* was able to transform it i nto a mathematical-statistical theory which prefigured modem information-processing theories and thus extended Guthrie' s i nfluence into the present . K e y Terms anticipatory response

law of contiguity

associative inhibition

law of frequency

fatigue method incompatible response method

law of recency maintaining stimuli

movement-produced stimuli one-trial learning stimulus sampling theory threshold method

Annotated Biblio graphy

An excellent cro ss- section of Watson' s thought is p resented in B eha viorism (New York : f'1orton, 1 924) , while the student wanting to savor a brief introduction to Watson' s amusing writing s tyle would find it p rofi table to read the fam o us "little Albert" article by Watson and Rosalie Rayner, " Conditioned emot ional reactions" (Jou rn a l of Experimen ta l Psychology, 1920, 3 , 1 -14) . G uthrie' s views are well p resented in h is The psychology of lea rn ing ( New York : Harper & Row, 1 935) . E s tes' s " n eo- Guthrie" theory is explained well in h is article, "The statistical appro ach to learning theory , " in S . Koch , ed . , Psy­ chology: A study of a science , vol . 2 ( New York : McG raw-Hill, 1959) . Excellent biographical material on most of the learning theorists covered in your text is to be found in D . P. Schultz, A history of modern psychology ( New York : Academic Press, 1 969) . * Estes has recently returned to the development of his statistical learni ng theory, making l ib eral use of com p uter technology . He hopes that his work will poin t the way, b y slow degrees, to the develop m en t of the kind of p recise general learning theory that Hu ll envisioned (Estes, 1 976) .

Learning throug h R einforce m ent : Thorndi ke and H ull

In this ch apter w e will explore the maj or princi ples develop ed by two theorists w ho saw connection s between stimuli a n d responses as resul ting from rei n ­ forcement mech an isms . No tice how these theorists altered their pri nciples to handle potentially disconfirrning results of other researchers' experimen ts as well as how the various laws were used to try to p red ict n ew b ehavior. The theorists presented in the preceding chap ter all believed that learn ing was a matter of the contiguity of stimuli and responses . This view was used in d efense of teach ing through rote repeti tion . The conseq uences of a response to the behaving organism were seen as importan t only i'f they served to ch ange a s timulus situation . In contrast, the theorists presented in this chapter and i n Chapter 4 all believed that the con seq uences of a response were much more important for p ro ducing learn i n g than contiguity alone was . Pleasant conse­ q uences were seen as providing optimal conditions for the formation of a bond b e tween a stimulus and a response . These theories took direct issue with the idea that "practice makes perfect . " Teachers were d i rected to focus on the rei n ­ forcin g aspect o f school situations rather than on rote repetition . Because reinforcemen t plays such a n im portan t part i n these theories, let us examine the mea n ing of this concept . Although all the theorists we are goi ng to discuss used the concept in sl ightly different ways, they all considered it to be somewhat like the popular notion of a reward . Th is is a very differen t mean ing of re in forcement fro m that used by Pavlov . For Pavlov, reinforcen1ent was seen as the confirmation of a CS by a subseq uent US . Pavlov's concept refers to a relationship between signals or stin1uli rather than to a n effect of the responses emi tted by the orga nis m . Yo u should thus be careful to disti nguis h between these two meanings of the term . The firs t theory we will exa n1 i ne is that of Edward Lee Thorndike . From the time of the publication i n 1 898 of his dissertation o n ca ts' escaping fro m puzzle boxes un til the late 1930s, Thorn d i ke had a strong influence on most learning theoris ts i n America . Although Pavlov made no acknowledgment of Wa tson' s theory, he was specific i n pointing out the critical and germin al role of Thorn di ke' s ideas and con trib utions to research . . . . the A n1erican School o f Psychologists-already i n terested i n the co m pa ra­ tive study of p sychology-ev inced a d isposi tion to subj ect the h i g hest nervous

Thorndike and Hull

51

activ i t ies o f animals to experi mental analysis under various specially devised conditions. We may fairly regard t he trea tise by Thorndike, Th e An imal Intelli­ gence (1898) , as the starting point for systematic investigations of this kind. [ Pavlov, 1 960, p. 6]

The gestalt theorists to be reviewed in Chapter 5 gained the attention of the American psychological establish ment largely through their attacks on Thorn dike . Thornd ike was able to gain acceptance for a mech anistic, experimentally orien ted appro ach to the study of learn ing as a replacem ent for mentalis m ( t he use of assumed umind" or mental even ts to explain behavior) wi thout the exce s­ ses of Watson's theory. He made the S-R bond , rather than tho ught, t he focus of learning. Thorndike ' s early w ork wi th cats marke d the beginnin g of an Amer­ ican tradition of investigating the b asic p ri nciples of learning, using animal s urrogates to learn b asic facts which were t hen assumed to generalize to human behavior. Both H ull and Skinner ( to be presented in Chapter 4) also used rats and pigeons almost interchangeably with human subj ects in developing t he ir m aj or principles . They also retained the behavioristic and mechanistic b ias of Thorndike's w ork . Their approaches to developi n g learning theories, however, were as opposite as they could b e . H ull tried to develop theories in t he p attern of the p hysical sciences, b ut after h is death most American learning theorists b egan to tum away from s uch efforts . American p sychology had begun with the philosoph ical theorizing of William James, who, as the teacher of Thorn d i ke , had seen his former p upil tum p sychology i n to a science characterized by d irect observation of behavior and experimentation (Hilgard and B ower, 1 975) . H ull's intention was to be the New­ ton* of learning theory, and to develop a calculus of behavior through applica­ tion of the principles of both formal logic and the experimental method . In spi te of m any years of dedicated and careful work b y H ull and h is follow­ ers, this effort failed . H ull' s failure to develop a theory of learn ing of the preci­ sion of Newton' s theory of m otion was not due to lack of effort or of inspirati on , nor was the p roj ect intrinsically fool is h . Rather, i t was the complexity o f the learning p rocess, as revealed by H ull ' s work, that defeated him . In retrospect, one of H ull' s greatest contributions may h ave been in demonstrating that the s ubj ect matter of the learn ing psychologist is fun d amentally m uch more compli­ cated than the p henomena investigated by Newton and the p hysics of his tim e . Following t he collapse o f H ullian efforts to develop a un itheory of lea rning, learning psychologists retreated e ither into developi n g limited models ab out specific types of learning p henomena or into the stricter empirical appro ach of focusin g on observable S-R relationships, as advocated by the Skinnerians . Hull's infl uence , however, continued t o be felt through the w ork o f his many talented students, who h ave collectively p rovided the maj or behavioristic alter­ natives to the Skinnerian approach . Some, like Spence, p aralleled Skinner in accepting contigui ty a s the mechanism for learning condi tioned reinforcers and * S i r Isaac Newton { 1 642-1727) was an English p hysicist and ph ilosop her . He i s best known for m athematical expressions of h is laws of gravi ty and motion .

52

The History of Lea rn ing Theory

reinforcement as the mechanism for learning overt responses . Others, like Mil­ ler, extended the drive-reduction ass umptions of H ull into new areas ( in M iller' s case, into imitation) . Edward L . Thorndike (1 874 - 1949)

Before Thorn d ike, most conceptions about animal behavior were dominated either by the assumption that an imals reasoned much like human beings, or explanations in terms of instinctual mech an isms . Thornd ike openly despised giving animals human characteristics (an thropomorp h ic proj ections) and sought to explain an imal learning as the result of simple events and principles . He publicly presented this mechanistic replacement for an imal reason with the publication of h is doctoral dissertation resporting the methods by which cats solved puzzle box problems (Thorndike, 1 898; see Figure 3 . 1 ) . After observing the patterns of learn ing to escape from the b oxes demonstrated by h is five felines, Thorndike stated that animal learning is a matter of the gradual "stamping- in" of stimulus- response bonds thro ugh trial and error. If Thornd ike had stopped wi th providing a mechan istic theory of an imal learning, h is i mpact would have b een minor. Thornd ike, however, saw nothing i n his observations to convince h im that h uman learning was in any way qualitatively different from an imal learn in g . With this position , Thorn d ike directly opposed the dualistic doctrine which declared human learn ing to be insightful or an act of getting the " idea , " while beasts were like mach ines controlled by thei r in­ stinct s . He also opposed the doctrine of animal reason (Bolles, 1 975) . By adapting to the field of learning Darwin's conceptio n of a continuity between men and beasts, Thornd ike in tro duced the assu mption now known as equi p otentiality i n to American psychology . Th is concept is based on the belief tha t the laws of learning are independent of the types of stimuli used, of the responses studied , and of the species to which the laws are appl ied . These assumptions provided the rationale for the use of an imal subj ects in the study of the laws of learn ing, and Thorn d ike was the firs t to use ani mals for th is purpose . An imal subjects have the important advantages* of us ually being ava ilable when needed and of not be ing able to express the ir obj ections to shock and food deprivation p rocedures . More critically, if the study of the behavior of animals can tell us about the laws govern ing hun1 an learn ing, then an imal behavior ( and human also) , which can be measu red more obj ectively than human thinking, beco mes the approp riate subject n1atter of psychology. Thornd ike prefigured the practices of modern be havi oral modifiers (see Chapters 6 and 1 0) by h is willingness to generalize fro n1 cat studies to human applications . T h orn d i ke t h o u g h t t h a t l ea r n i n g is u s u a l l y a m atte r of t he a u t o m a t i c stren g t he n i n g of S- R b o n d s a s a res u l t of a t r i a l -a n d -e r r o r e x p e r i e n c e . H e ass u m ed t h at t he l aws govern i n g s u c h l e a r n i n g a re t h e s a m e f o r a n i m a l s a nd h u ma n s .

* Advantages, w e m us t no te, only fro m the point o f vi ew o f the experimen ter.

Thorndike a n d Hu ll

53

Figu re 3 . 1 A puzzled cat in one of Thorn dike's puzz le boxes . Pressing the lever just behin d the cat pu lls the cha in wh ich opens t h e door, allowing th e frus tra ted feline t o escape.

How Learning Occurs : Thorndike's Early Theory Thornd ike' s theory remained essentially unch anged from 1 898 to the early 1930s . The core of this theory was three m aj or law s : The first was the law o f effect, which stated that " responses j us t pri or to a satisfying state of affairs are more likely to b e repeated" and "responses j us t p ri or to an annoying state of affairs are m ore likely not to be repeated" (Thorndike, 1913, p . 2) . Animals were viewed as tending to try to maintain satisfying states of affa irs and not to maintain annoyi ng states of affa irs . Hence, in spite of the subj ective tone of the words " annoy" and "sa tisfy , " Thorndike defined these terms b y the animal' s behavior, without recourse to mentalistic concepts . Satisfiers " s tamped" re­ sponses i n and annoyers " s tamped" them out (L efrancois, 1 972) . These " stamp ­ ings" h e saw as d irect, mechanical, a n d not req u iring consciousness of the learning or awareness of the learn ing . L earn ing he therefore defined in terms of S-R b on d s that are gradually " stamped" i n to t he bra i n . The completed bon d s then function much like i n herited connection s ( instincts a n d reflexes) . This defini ti on is very similar to Pavlov' s neurological speculation s . Thorndike's second law was the l aw o f rea diness, which was s tated i n terms of hypothetical neural units . Th is law stated that satisfaction or annoyance de­ pends upon the state of the behaving organis m . When a conduction unit of neurons is ready, then conduction is satisfying. When the conduction unit is unready, then conduction is annoying . When t he conduction un it is ready and

54

The History of Lea rn ing Theory

no conduction occurs, t hen the organism would be frustrated or annoye d . In a sense, this was much like the expectancy pri nciples advocated by the cognitive theorists, to be d iscussed in Chapter 5 . H is t hird law was the l aw o f exercise and represented a concession to a contigui ty i nterpretation of learning . Thornd ike stated that use of connections acts to strengthen the connections and disuse acts to weaken t hem . The " use" p ri nciple pri marily explains repetitive hab i ts s uch as motor skills and memory of poems . The " d isuse" principle explains forgetting in general . While admit­ ting that contigui ty factors could infl uence S-R bonds, Thornd ike criticized using this principle wi thout including the law of effect ( Hilgard and Bower, 1 975) . Thorndike took exception to the idea that drill alone can produce learning! I n T h o r n d i ke ' s t h e o ry , learn i n g o c c u rs w he n : ( 1 ) a res p o n s e l e ad s t o s at isfac­ t i o n o r the avo i d a n c e of an n oya n c e ( l aw of effect) , (2) the o rg a n i s m is read y to res pond ( l aw of read i n ess ) , a n d (3) t h is l ea r n i n g is en h a n ced by p ract i c e ( l aw o f exerci se) .

Thornd ike also proposed five minor laws, as follows : 1 . The law of multipl e re spon se : Th is law states t hat when a learner faces a problem and the firs t response does not produce a satisfying s ta te of affairs, the learner will try other response s . Th is work ing through a h ierarchy of possible sol utions is the essence of trial-and-error learn i n g . Succe ss, of course , sta m ps in the successful res ponse . A person loca ting lost keys on top of a desk after rum magi ng through his/ her entire ho me will look on top of the desk when t he keys are lost aga i n .

2. The law of set o r attitude : Leam i ng does no t exist independen tly o f the state of the behav i n g organ ism . If you are feeling de pre ssed , you may give up wi tho ut finding a sol ution . Set is also seen as cul tu rally de tern1 i ned predis­ posi tions to behave in specific ways . I f a person ' s cultural reference gro up has taught that the best res ponse to a frus trating si tua tion is s to ic indifference , that person when fru s trated will behave very d i fferen tly fro m the person whose group stresses aggressive reac tions to frus tra tion .

3 . The law of pre potency of el ements : Th is is the ab i l i ty s hown by the learner to respond only to the relevant aspects of a situa tion. I t is like the m odern Russian ( see Chapter 8) analysis of the second signal system as the means by which man can signal hi mself to restrict a tten tion to w ha t is most likely to be im portant in solv ing a proble m . It is al so like the expe ctancies d iscussed in the cha pter on cog n i t ive learn ing the ori es (Cha pter 7) . 4 . The law of res p onse by analogy refers to the ab ility of humans to react to a novel si tua tion w i th the res ponses learned i n a fa miliar si tua tion . Th is sug­ ges ts that responses can be tra nsferred across si tua tions . Thorn dike also says that the degree of transfer is a funct ion of the sim ilari ty of the two situations (in Lefrancois, 1 972) . An example n1 ight be the transfer of balancing and steering skills from rid i n g a b icycl e to ri d i ng a motorcycle . This concept is akin to a generaliza tion of response tactics, or response s tra tegi es .

Thorndike and Hull

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5 . The law of associative shifting : This law refers to a t ransfer of s t imulus control from one cue to ano ther. As such, i t is m uch l i ke classical condit ion­ ing . The firs t cue is l i ke the US and the second like the CS . The p ower of the first cue to control the response, however, is shifted to t he second cue by g radually altering the firs t cue until it becomes the second cue . Thorn dike mainta ined that classical con d i t ioning was a special case of associative shift­ ing (in H i l ga rd and B ower, 1 9 75 ) . A proce d u re of th is type is used in p rod uc­ ing errorless learn ing b y s h ifting cue control from an easy cue d imension to a more d ifficult one ( see t he d iscussion of errorless l earning or fad ing in Chap­ ter 9) .

How Learning O ccurs : Thorn dike 's La ter Revisions Thorn dike made several important mo difications in h is theory after 193 1 . The firs t of these was his repudiation of the law of exercise . Thorndike had never been co mfortable with the idea that practice alone could s trengthen res ponse tendencie s . In 1 93 2 , Trowbridge and Cason rep orted a series of stud ies by Thorn dike i n which practice alone failed to p ro duce learni n g . These studies consis ted of having blindfolded s ubj ects a ttempt to draw a 4 - i nch line with and without feedback about their accuracy . Wi thout feedback, there was no im­ p rovement i n accuracy, even followi ng 1 2 d ays of practice . This author, how­ ever, has used the experimen t as an exercise i n beginning experimen tal p sy­ cholo gy co urses and has found that while Thorndike's basic results are s till obtained , the opportun i ty to watch a subj ect wi th feedback allows the watcher later to show so me improvement wi thout feedback . Thorndike would of course explain th is res ult as implicit rehearsal of the connection leading to an internal "confirming reaction" or satisfier ( Hilgard and Bower, 1 975) . It should be clear by this time that the d urability of Thorn dike's theory was partly due to h is flexibility and willingness to borrow concepts, which prevented h is theory' s e arly obsolescence . Another mo dification of the early theory involved a reduction of the role of punishment fro m that of a direct weakener of bonds eq ual in power to reward, to an indirect infl uence which might lead an animal to change its res ponses when confronted w i th a n annoyer. Thorn dike collected various types of evi­ dence, including testimonials, about the relative efficacy of reward and pun­ ishment from b iograph ies ( Hilgard and Bower, 1 975) . As w ill be seen , this deemphasis of pun ishment in learning is sim ilar to the m inor role assigned pun is hm ent by Skinner . Thorn d ike's revised law of e ffect, with its dee m ­ phasis on annoyers, i s called the trunc ated l aw o f e ffect. Thornd ike was � ware of the attacks on h is ideas by the gestalt theoris ts . I n concession t o their research fin dings, h e added a n organ izational principle t o h is theory ( in Hill, 1971) . This princ iple of belongingn ess sta tes that a connection between two units or ideas can b e established more easily when the two un its or i deas are perceived as belonging together . In human learn ing, th is principle was used to account for the closer connection between the i deas " Davi d , student" than the i deas " s tu dent, beginning" in the sentence: " Davi d is an eager b u t not

56

Th e History of Lea rning Th eonJ

experienced stu d ent, beginning in psychology . " This, in s pite of the fact that " beginning" is closer i n time and space to "s tudent" than to " David . " Thorndike also used the principle of belongingn ess to explain the subj ect's perceptions of the contingencies related to reward and punishmen t . If a student saw a failing grade as due to her personality an d not to her w ork, then the contingency would not " belong" to the work and her work behavior would not change . Arden t feminists, seeing the calculated u se of the p ronoun "her," m i ght see the pronoun as " belonging" with the m ention of fa ilure and might conse­ quently experience the sen tence as an annoyer . Other persons, not seeing a relationship between " her" and " fa iling grade," would experience no emotional reaction. Thornd ike made a third modification that was a direct provocation to the gestalt view of seeing stimulus-response relationships as wholes . The modifica­ tion was to state that S-R relationships were p olarized or unid imensional. This principle would predict that if one learned to translate Jap anese into English , one would b e u nable to translate English into Jap anese with equal skill. Another of his innovations was a principle titled the "spread of effect . " This principle stated that the influence of a s atisfyin g state of affairs acts not only on the connections to which it belongs, b ut on temporarily adj acent connections, both before and following the "sa tisfying connection" (Hilgard and B ower, 1975) . This effect can be thought of as generalizati o n of reward . Thornd i ke evoked this pri nciple to demonstrate the mechanistic nature of the strengthen­ ing of bonds . An example might be developing a liking for a dull sociology co urse which was taken at the same time as a highly reward ing course in psychology, i n which one learned a great deal, earn ed an "A," and was con­ stantly amuse d . Another example m ight be liki n g the p ersons sitting near you i n the psychology class . Thorndike s a w th is effect as taki ng place wi thout aware­ ness . Today , most theorists would explain these examples by the pri nciples of simple Pavlovian conditioning.

Applica tions Thorn dike was no t interested only i n theoretical issues . He p resented n umerous suggestions for the application of his theory to the schoolroo m . He pointed o ut three maj or areas that s hould rece ive the teacher' s attention . These were : j udg­ ing the difficulty wi th wh ich the teacher would be able to apply satisfiers and annoyers to bonds to be formed or broken, identifying the bonds to be formed or broken, and identifying relevan t satisfiers and annoyers . As we will see i n Chapter 10, these areas are maj or concerns of modem contingency managers using the operant or Skinnerian model of learn ing. Thorndike was also concerned with the motivational aspects of the classroom, and he recognized the importance of the pupils' attitudes towards learn ing. He listed five factors which he felt educa tors should be aware of to improve learning (Thornd ike, 1913) : 1 . The pupil's interest in the work 2 . The pupil's i n terest in i mprovemen t in performance

3 . The sign ificance of the lesson for some goal of t he p upil

Th orn dike and Hull

57

4. The pupil's awareness that a need coul d be satisfied b y learning the lesson 5 . The pupil's concentration span or attentiveness to the work

Many of Thorndike ' s suggestions for teachers came from h is mechanistic orien­ tatio n . He believed that transfer was always sp ecific and never general, and that therefore a p upil s ho uld make some connections which would be co mmon to life situation s to be faced after schooling ende d . When transfer occurs between two situations that appear different, Thorndike believed that some of the stimuli of the two situations must appear in both ( Hilgard and B o wer, 1975) . This was known as his " identical elemen ts of transfer" theory (similar to G u th rie' s and E s tes' s explanations of generalization) . This theory led him to advocate the training of specific skills which could be use d in occupational settings rather than in general educatio n . The general pri nciple governing transfer of learning to new situa tions was that of " a ssociative s hifting, " which was discussed earlier. T h o r n d i ke m ad e m an y s u g g e st i o n s for i m p rov i n g teach i n g . T h e s e i n c l u d ed p ay i n g atten t i o n to m otivati o n factors a n d m a k i n g w h a t was ta u g ht as s i m i l a r a s p o ss i b l e t o the s ki l l s w h i c h p u p i l s wou l d n eed after g rad u at i o n .

Th orn dike's Positions on Major Issu es Na tu re /n u rture Thornd ike was a strong environmentalist who was also willin g to incorporate concepts from biologists, such as adaptation to the envi­ ronment . He saw d ifferences in intelligence as quantitative and i nvolving inher­ ited differences in the number of b onds available for "selecting and connect­ ing. "

The how of learn ing

Although Thorn dike ' s early t heory included the con­ tiguity p rinciple of the law of exercise , he l a ter d ropped this law . Throughout h is career, he maintained that the consequences of behavior ( whether it led to satisfiers, annoyers, or no con sequences) are more important in predicting learn ­ ing than the relationships o f s timuli a n d responses .

The w h a t of learn ing

Thorndike was willing to admit the existence of thought and the p ossible mediating role of ideas (as in rewarding yourself by thinking, "Okay , I got it right! " ) , but he did no t think t h at the basic unit of learn ing can be anything o ther than S-R bond s . In the formation of these bonds, he b elieved, the organism' s expectancies can alter which stimuli are selected for connecting, but he did not view thoughts and awareness as necessa ry for learn ing .

Con tin uitylnoncon tinu ity a n d o ther iss u es

Thorndike emphasized that bonds are slowly " s tamped in" or connected in a continuous man ner. He admit­ ted , however, that apparently i nsightful ( noncontinu o us) puzzle solutions can result if the organ ism selected new combinations of p reviously " s tamped-in" connections, or thro ugh the mechanism of " response by analogy" (one of the minor laws) . He felt that s uch insightful- appeari ng beh avior is extremely rare in

58

The Histon; of Leanz ing Th eory

animals and can be explained even in humans i n terms of hab i ts and analogies . Thorndike pioneered the use of animals to explore the basic laws of learning and through this made behavior a central concern of psychology . He w as an ex­ tremely strong determ i n ist and had no use for s uch men talistic concepts as "free will . ' '

Perspective Thornd ike introduced a theory of learn ing based on the mechanical " selecting and connecting" of stimuli and responses . He made animal research and the study of behavior the b usiness of p sycholo gists and, based on h is early observa­ tions of the escape behavior of cc- ts fro m puzzle boxes, he concluded that learn­ ing is essentially " trial and error, " with the satisfaction of s uccess acting to " stamp in" S - R connections . Compared to the radical behavi orists, he was ex­ tremely flexible . As an example , in 1 929 he added a fun d amen tal new principle, belongingness, as a concession to the research findings of the gestalt cognitive theorists . He was highly interested in applications of h is the ory, especially i n the a rea o f teach ing , a n d h e served for many years o n the staff o f Colu mbia's Teachers College . In h is educational theorizing, he s tressed drill , if tied to moti­ vational variables, and the learning of h ab i ts . Thro ug hout, he remained a mech anistic S- R theorist who felt concepts s uch as " un derstand ing" to be hocus pocus . His work has influenced most learning theories, 'both those of his era and more mo dem theories . Along with his other germinal contributions, he firs t made the reinforcem ent approach to learn ing a strong contender to contig uity and cogni tive theories . Clark L . Hull (1 884 - 1952)

Ra ised in rural Michigan, Hull in 1 905 began the study of ma thematics and engi neering ( Hill, 1971) at tiny Alma College. D u ri ng the two years he spent there , Hull was reported to have shown part icular interest in applications of the logical pri nciples of E uclidean geome try to the develop ment of theories . This method of starting with ass umptions and p ro gressing to testable theoren1 s was later i ncorporated into his theory of learn i n g . Striken wi th poliomyeli tis at the age of 24, he resumed h is stud ies th ree years later at the Un iversity of Michigan, where he concen trate d on the study of psychology. He received his Ph . D . fro m the Un iversity of Wisconsin in 1 9 1 8 . I n 1 928, he publ ished a book on aptitude testing after teach ing a course in that s ubj ect at the U niversity of Wisconsin. I n 1929, he accepted a position a t the Institute of Psychology a t Yale University , where he remai ned un til his death (Sahakia n , 1 976) . I n 1933 , he published a book enti tled Hy pnosis a n d S llggcstibility . As the head of the gro up studyi ng the place of learn ing in human affairs at Yale, Hull was able to develop his theori es of learn ing, generate in1mense amo unts of research , and cond uct a weekly se mi­ nar whose members i ncluded Neal Miller, 0. H . Mowrer, John Dollard , and Kenneth Spence . Contributions by this gro up to learn ing theory will be explored in this chapter an d in Chapter 7. H ull was greatly impressed by the E nglish translation of Pavlov' s Con­ ditioned Reflexes ( Pavlov , 1 960) . Initially, he accepted Pavlovia n expla nations of

Thorn dike a n d Hull

59

learning based on contiguity as well as the mechanistic, behav ioristic orienta­ tions of both Pavlov and Watson . Two important events, however, motivated him to develop a theory that d iffered greatly from those of Watson a nd Pavlov . F irst, he was influenced by the work of the cognitive learning theorists . H ull h ad published a p ap er on concept form ation in 1 920, i n which he took the purposes and insights of Tolman and the gestalt theorists ( see Chap ter 6) much more seriously than Watson, w ho saw fit to deny cognitive p henomen a . H is first p ap ers on learning (Bolles, 1975) were attempts to explain purposiveness in behavior by Pavlovi an S-R a ssociations . The second maj or event infl uencing Hull was the revised "law of effect" theory p resented by Thornd ike i n the early 1930s . Hull wrote a long a n alytical review of one of Thorndi ke' s new books ( Hull, 1 935) i n which he accepted and adopted Thorn d i ke's emphasis on rein­ forcement, rather than contiguity, as the primary factor i n learning. Also influ­ enced by Darwin's t heory, Hull saw learn ing as a means for organisms to adapt to their environments i n order to s u rvive. Therefore, h is t heory was designed to show how organisms' b o d ily needs (drives) interacted wi th the environmen t i n the learning p rocess .

The S tru cture of Hull's The ory To h is desire to develop a theory of learning incorpora ting m otivation variables and to explain the complex p henomena of the cognitive theorists in simple, connectionist terms, Hull added a desire to develop a p sychological theory in the mathematical-logical form of Newton' s theory in physics . Hull believed that p sychology could best p rogress by s tarting with specific assumptions about t he relationships between stimuli and resp onses . These assumptions or p ostulates were to be b ased on experimental evidence , however scanty , and in tum to be used as t he basis for deriving (deducing) testable theorem s or laws of be havior. These deductions or theorems were to be sta ted in term s o f concrete, observable behavior . If the t heorems were not supp orted by experimen tal research , the p ostulates were to be modified until they resulted i n satisfactory deductions . This emphasis on formal p rinciples of theory construction indicates that Hull's mathematical and engineering training at Alma College produced a lasting in­ fluence , one which led him into methods of theory construction q u ite unlike those of h is predecessors in p sychology . His early tra ining may also have been responsible for h is a ttempts to s tate his laws of behavior as p recise mathematical equation s . These equation s were developed by observing stimulus conditions (inde p endent variab les) and res p onses (depen dent variab les) and then attempt­ ing to fin d values for the inferred mediating or i ntervening variables congru en t w i th the data . E ssentially, the p rocess w a s one of fitting curves t o the values until a set of constants or values for the mediating variables would successfully predict t he known res p onse variables from the measured stimulus conditions . Hull called h is system "molar behaviorism" because his un its of "what­ was-leamed" are w hole (large- unit or molar) hab i ts rather than b onds between tiny (molecular) muscle movements (as in G u thrie' s the ory) and individual stimuli . The system is rigorous i n that h is inferred constructs a re not hypo theti­ cal neural circui ts or aro used areas wi thin the brain, as in Pavlov's theory .

60

Th e History of Learn ing Theory

Rather, his intern al mediating variables are processes assumed to acco un t for the relationsh ips between externally observable independent and dependen t vari ables, n o t requiring the surplus meaning o f hypothesized ne urological en­ tities . His intervening variables have their effects at two stages : The first, inter­ n al stage involves the organism's reaction s to the indepen d ent v ariables, and the second, internal stage is that of the organism's tendencies to make responses . H ull retained this basic fo ur- stage theory of behavior-with independent, dependent, and two stages of internal variables-from i ts firs t full presentation in P rinciples of Beha vior ( Hull , 1943) to h is p osthumously p ublished second volume, A Beha vior System ( Hull , 1952) , i n spi te of many revisions in the 1952 book . The i ntervening variables of the 1 943 postulate system will now be pre­ sented . The 1 952 revisions of the system of in terven ing variables will be dis­ cussed i n a l ater section of this chapter.

H u l l d ev e l o p ed a t heory of l e a r n i n g bas e d o n t he p r i n c i p l es of f o r m a l l o g i c . T h i s t heory i n corp orates e q u at i o n s re l ati n g i n terven i n g va r i a b l es w i t h i n o r­ g a n is m s to s t i m u l u s c o n d i t i on s ( i nd e p e n d e n t va ri a b l es ) a n d b e h av i o r (d e­ p e n d e n t vari ab l es) . The u n its of l ea rn i n g a re m o l a r h a b i ts .

Major In tervening Varia bles D rive Drive (0) is an aroused state of an organ ism caused either by lack of some needed substance or by painful stimulation . It h as both the specific s timu­ lus properties wh ich Guthrie labeled "maintaining stimuli , " and a generalized energizer function . This latter property predicts th at a hungry an imal who is also th irsty will run faster for a food reward than an an imal who is only hungry , because the h un gry and thirsty an imal has two so urces o f generalized arousal. In the absence of prior learning, the arousal component of a drive causes the an imal under high-drive con d itions to emit need-terminatin g behaviors . Either these behaviors will lead to the reduction of the drive state or the an imal may d i e . Behaviors lead ing to drive reduction become connected both to the in ternal stimuli associated with a specific drive state an d to environmental stimuli asso ­ ciated with drive reduction . These connections between s timuli and responses are called habits . The s trength o f these habits is assumed to increase on every trial on which drive reduction occurs . Succeeding trials a d d progressively less to the strength of the S-R bon d , a phenomenon which is called the princi ple of declining returns. This principle is illu stra ted in Fi gu re 3. 2 .

Ha bit Strength

Habit strength ( S HR) is the strength of the bond con necting

a stimulus with a res ponse . Hab its represent permanent connections wh ich can increase but never decrease in strength , and form the basis of lon g- term learn­ ing. Postulate 4 states that: Habi t s trength increases when receptor and effector act iv i ties occur i n close temporal contigui ty , prov ided their approxi m a tely cont ig uous occurrence is as­ sociated w i th primary or secon d a ry rei nforcement. [ Hull , 1 943, p . 1 78 ]

Thorndike a n d Hull

61

-0 c 0 en a: '

Cf)

0 ..c

......

CJ) c Q) '­

......

Cf)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

R e i nforced T r i a l s

Figure 3 . 2 The h ypothetical s trength of th e S-R bon d goes up most rapidly on the firs t few tria ls a n d then goes up less with each su cceeding tria l. Th e a m o u n t of increment con trib u ted by ea ch su cceeding trial app roach es, but never rea ches, zero .

When H ull developed h is e q ua tions depicting t he variables responsible for developing a ten dency to emit a specific response i n the presence of a specific cue, he assumed S HR always to be i n a multiplicative relationship to D . Thus, either zero S HR ( no p revious connecting of a stim ulus and a response) or zero D would prevent a p articular stim ulus from eliciting a p articular respon se . Hull's ( 1943, p . 253) postulate 7 is summar ized by H ilgard and Bower ( 1975) : " Habit strength is sensitized into reaction p otential by primary drives active at a given time . ''

Reaction poten tial

Reaction potential ( S ER) refers to the total tendency to

make a given learned response to a given stimulus a t a specific point in time . As we j ust s aw, both experience with the resp onse in conj unction with a particular stimulus (SHR) and a mo tivated state (D) are n ecessary for values of SER o ther than zero ( since zero times anything equals zero) . In the 1 943 postulate syste m , S E R w a s also seen as b e in g infl uenced b y o ther intervening variables . We will now examine some of these variables.

Rea c tive inhibition

Responding (whether reinforced or not) requires mus­ cular effort, and such effort leads to fatigue , w h ich is a function o f the amount of effort. Fatigue acts to inhibit further resp onding and causes the b uildup of reactive inhibition (I R) . Reactive inhibition is specific to p articular responses and spontan eo usly d issipates a s a function of time after respondin g cease s . IR is one of the causes of extinction , and i ts d issipation is seen as explaining the spontaneous recovery of responses that appeared to h ave been extinguishe d , after a rest p eriod . Similarly, p erformance of w ell-learned habits m ay i mprove after rest perio d s . This is called the reminiscenc e effect ( i n Hergenh ah n , 1 976) . I R w a s also used t o explain the res ults of experimen ts s uch a s those by Hilgard and M arquis (1935 ) , who found performance to b e s uperior when learning trials were separated by res t periods rather than all given at once ( massed trials) . With distributed trials, t he IR h as more chance to dissip a te . In m u s t be subtracted fro m D X S HR before the e quation can b e used to p redict tendencies to respond .

62

Th e Histo ry of L earn ing Th eory

Condition ed inh ibition

Like IR, con ditioned inhib ition ( S 1R) was hypothe­ sized to subtract fro m the s trength of the tendency for a response to be emitted . Unlike IR , however, S1 R was assumed to be specific to a p a rticular stimulu s and a p articular response. H ull (1943) suggested that prolonged responding, rein­ forced or not, would eventually be painful (resulting in the b u ildup of IR ) . To sto p respond ing would be to red uce the drive to avo id this pain and would be reinforcin g . This tendency to sto p respond ing would be con ditioned to any cues or sti mulus traces "which chanced to b e presen t" at the time the organ ism reduced the drive to avoid the pain and/or fatigue occasioned by p rolonged responding. Thus, the tendency not to respon d is as much a learned habit as S H R and , like S H R, it b uilds u p with each re sponse . Why, then , does the organism normally only stop responding when not reinforced? Hull would an swer that d uring reinforced trials, S E R (the total excitatory po tential) also b u ild s up , and this overcomes the effects of the buildup of S1 R . D u ring extinction , there is no d rive reduction to b uild up S E R and hence the combined influences of S1 R and I R eventually become _greater tha..1 that of S ER , and responding stops . Thus, H ull explained S 1 R as a conditioned cause of extinction , similar to Pavlov's explana­ tion of extinction , which stated that conditioned inhibition b u ilt up as a result of S-R links not being confirmed through the following of a CS by a US . H ull' s conceptualizations of IR and S 1R lead to some p aradoxical predictions. For exam­ ple, since S H R gradually b uild s up more and m ore 'slowly (the principle of d eclining returns) and each trial leads to som e S1 R, continued practice should eventually lead to performance decreases (Glei tm an , Nachmias, and Neisser, 1954) . This suggests that H ull's inhibi tory pos tulates are perhaps one of the weakest parts of his theory . The tendency of extinction to become faster over several separate extinction sessions can now be explained . I u builds up with in each session and d issipates between sessions, leading to spontaneous recovery . S 1R, however, builds up in a continuing fash ion as a function of to tal tri als and hence has a greater inhib itory effect wi th each s ucceeding extinction session . I f a person q uits after several un successful attempts at a task, this would be interpreted as due to the buildup of In. Quitting would reduce the aversive effects of fa tigue and other sources of In and would re inforce the buildup of S 1R . Th is would lead to a reluctance to begin the task later, even thou gh I u has d issipated .

Oscilla tion fu nction

Although Hull had so n1e success in pre d icting the be­ havior of gro u ps of an imals, he fo und that h is dependent variables varied widely over individual anin1als, and even fron1 trial to trial in a single animal. He was holding the independent variables, s uch as hours of deprivation, con­ s tant. Since these independent variables were supposed to determ ine the inter­ ven ing variables, and they, in tu m , to acco un t for the dependent variables, wi de ind ividual varia tion presented a serious problem . To handle th is problem, Hull postulated the exis tence of a "fudge factor, " an oscil lation function or S0R . H e sugges ted that the threshold of respon se emission varies rand omly over time as a function of the a n imal's cond ition (Bolles, 1 975) . Response indeterminancy (S0R) was subtracted fron1 the o ther determinan ts of response s trength , and i ts

Thorndike a n d Hull

63

a mo un t was assumed to follow a normal curve pattern . Thus, when S0R is very large, even strong D and S H R may not lead to a response . When S0R is very small , even weak response tendencies may go over the threshold value needed to p roduce an overt behavior. As wi th other functions described by the normal curve, very large and very small values of S 0R are much less likely than med ial values . S0R was also used to explain which of two e q ually strong competing incom­ p atible responses will be expressed in a given situation . When S0R1 is less than S 0R2 for two e q ual reaction potentials, the lower S 0R 1 will allow its reaction p otential to b e expressed as a response ( H ill, 1 971 ) .

A qu ick s u 1n mary

As we have seen, SER refers to the total tendency to make a given response to a given stimulus . It is the final p ro d uct of all the other intervening variables, as shown in the formula :

I f i t is over the necessary threshold value, then behavi or will occu r . The amount that S E R is over the thre s hold for the expression of a p a rticular respon se will determine the strength of that resp onse or the total values of the dependent variable measures (response freq uency, response amplitude, and so on) . The level of the threshold for a given reaction is called SL R . I n H u l l ' s t h e o ry, d ri v e ( D) i s m u l t i p l i e d b y h a b i t st ren g t h ( S 11 R ) . B o t h t he s e v a r i a b les m u st e x i st at leve l s a bove z e r o to g en e rate a t e n d e ncy towa rd s a g i ven res p o n s e . I n h i b i ti o n g e n e rate d by fati g u e l i ke facto rs ( I R) p l u s c o n ­ d i t i on e d i n h i b i ti o n ( S ' R ) a re s u bt racted f r o m t he res u l t o f t h at m u lt i p l i cat i o n . R a n d o m os c i l l at i on s i n read i n ess t o res po n d ( S0 R ) m u s t a l so b e s u bt racted t o y i e l d t h e f i n a l pote n t i a l f o r res po n d i n g ( S E R ) .

Let us now look at an example of a mo tivated behavior i n H ullian terms . S uppose we were hungry in the middle of our class day ( hi gh 0) . This high D will both make us restless thro ugh its generali zed arous al effect and make us aware that our n eed is for food instea d of water, and so on . Let us suppose that in past times, being hungry under similar circumstances, we were able to ob tain candy fro m a hallway d ispen ser so that the cues of hun gry plus be ing at school were bonded to the response of operating the mach ine . Thus, we form ed a habit (SHR) of machine operation in t he p resence of t he cues of hunger and b eing at school . The last time we tried to get candy, however, the machine had failed to work i n spite of two d imes and three kicks . This experience of nonreinforcement would have built up a tendency not to use the mach ine, or S 1R . In addition , suppose that the machine is d ifficult t o operate a n d we have been asked b y our classmates to get some candy for them . Increasin g the n umber of mach ine­ operating responses, even if rewarded, will build up something like fatigue (In), which will ten d to in hibit further responding following several effortful at­ tempts to make t he machine work p roperly . Of cou rse , this reactive inhib ition ,

64

The History of L ea n1 ing Theory

because it dissipates over time, will have li ttle or no effect if we are hungry aga i n the next d a y . The rewarding effects of reducing fatigue b y s topping will gener­ ate a more permanent type of con ditioned inhib ition (S1R) , wh ich would be learning the habit of no t trying to operate this particular machine . There might also be a generalization of inhibition which would m ake us less likely to operate mach ines which are similar to the uncooperative machine of our experience . Even with low levels of tendencies not to respond (S1R) , h ig h drive (D) related to food deprivation, and a well-learned habit (SHR), we might " simply not feel i n the mood t o use the machine" o n a given d ay . When this i n h ib itory oscillati on effect is high ( S 0 R) , the impulse or action tendency (SER) to operate the mach ine may not be s tron g enough to impel us out of our seats and in to the hall where the machine is locate d . Conversely, if S 0 R is very low the tendency to operate the mach ine may go over o u r threshold for responding (SLR) even when we do not feel especially hungry . I

Hull's expla na tion of beha v ioral ch aining

H ull ' s postulate on reinforce­ ment p resented two corollaries . * The firs t stated that n eutral stim uli repeatedly and consistently associated with the onset of a drive reduction acquire the power to elicit the i ntern al cues associated with that drive . Since these cues make the organism likely to emit the habits that have been related to that drive, the formerly neutral stimuli now serve to create a conditi on of secondary or con­ , ditioned drive . The second corollary stated that formerly neutral receptor i m­ p ulses (stimuli attended to by the organism) w h ich occu r repeatedly and consis­ tently in conj unction with the reduction of either a p ri m a ry or second a ry drive (secondary or primary reinforcing states of affa irs) become secondary reinforc­ ers . As you can see , Hull did not d iscriminate clearly between the cond itions necessary to create secondary drives and those making s timuli effective as con­ d itioned (secondary) reinforcers . This confounding of learn ed reinforcer and learned drive properties of stimuli was carried over i n to Hull's explanation of how organ is m s come to perform a series of responses which u ltimately leads to the reduction o f a p rimary drive such as h u n ger. Let us further examine Hull's ideas about secondary reinforcemen t a n d secondary drive . Hull assumed p rimary re inforcement t o be the res ult o f a red uction i n a drive state-i n o ur example, the drive state of hun ger. Hull realized that although responses made during eating (chewing, s alivating, swal­ lowing, and so on) and the food itself constitute a powerfully re inforcing s tate of affairs, they do no t res ult in a n instanta neous reduct ion of a hunger drive . Why, the n , do the responses of eating (goal responses or R es) a n d the stimul i asso­ ciated with them (goal stimuli or S cs) serve as re inforcers? H ull (1943) suggested that the Pavlovian process of second-order conditionin g could provide an expla­ n a tion for food and eating as re inforcers . S ince cues generated by eating (S cs) are followed shortly by the altered s timulus cond ition of a reduced hunger drive which elicits the unconditioned or primary re inforcing response , the S cs be* Th is postu late and the two corollaries were pre sented formally i n the 1952 postu late syste m . The same assum ptions, w i th minor ( for o u r p u rposes) variations, were p re sented i n a more informal way in the 1943 system as part of Hull's general d iscussion of secondary rei n forcement.

Thorndike and Hull

65

come second-order or conditioned reinforcing cues whic h elicit a "respon se" o f second ary reinforcem en t . H o w , then, d o we account for organisms h avin g the m otivation necessary to learn long chains of preparatory resp onses which would eventually res ult i n food becoming available for eating? H ull thought that organism s beginning a chain of behaviors which would finally res ult i n e ating (or any o ther consum­ m atory response) would tend to make little res p onses similar to t hose made during actual eating. Thus, Hull woul d predict that t he organisms i nvolved in obtaining food would be salivating, chewing, and swallowing at low intensity w hile m aking the initial responses i n a complex chain of behavior that would result i n food . Because these anticipatory responses were like the respon ses m ade i n the presence of the actual goal of food ( Res) b ut "littler , " Hull c alled t hem little goal responses, or res . Since t he res were a ssumed to h ave only a fraction of the intensity of respon se s made to actual g oals (Re s ) , he also called t hem fractional antici p atory goal reactions . Like Res, t he res generate s timuli , whic h Hull n amed s Gs, or r G generated stimuli . Just as t he stimuli (S cs) p ro d uced by goal reactions b ecome secondary or con d i tioned reinforcers thro u gh their associations w i th pri mary reinforcemen t, t he scs j ust before t he fin al goal reaction ( the Re) also become conditioned re inforcers through being p a ired with the Scs . These scs would reinforce t he res and other resp onses occurring j u s t pri or to t he Re. In tum , s cs further removed fro m the goal s timuli and resp onses would become condi tioned reinforcers thro u gh the ir a ssociations with t he more pri mary scs . The process was one of developing a chain of rein­ forcers i n w hich drive reduction is the unconditioned reinforcer, t he Sc is the secondary reinforcer, t he first sc is a third- order reinforcer, the second Sc is a fourth- order con ditioned reinforcer, and so on . This chain o f stimuli was as­ sumed to function much like G u thrie' s movement-p roduced stimuli in integrat­ ing a chain of responses (both overt responses, l ike w orking to gain access to foo d , and the covert res) and in reinforcing t he occurrence of each behavioral link in t he chain . This model c an account for t he reinforcement of the ch ain of responses, but w hat about the problem of accounting for t he s tu dent's m o tivation to begin the chain? Remember H ull' s first corollary to his p os tulate concern i ng reinforce­ men t . This corollary stated that formerly neutral stimuli associated with a drive and its reduction will develop the p ower to trigger secondary or conditioned drives. Thus, the first Sc i n the chain acq uires drive properties fro m being associated wi th the goal stimuli (Scs) , w hich derived their drive pro p erties from being paired with the hunger drive' s red uction . The scs both provide the motivation for overt responses s uch as b ar-pressing to obtain foo d , going to t he feeding mechanism to obtain foo d , and so on, and reinforce both the res triggered by t he drive state and the overt response s . The res, as you remember, generate the s cs, and the " glue" holding the entire chain of behaviors together is the p assing down the chain of the effects of t he final d rive reduction or p ri m ary reinforcin g state of affairs . Because the res are similar to t he actual goal reactions (Res) , t hey are strengthened by generalization every t ime the Re is strengthened by drive re=

66

TJze H istory of L ea rn ing Theory

d uction . Since the re or res closest to the primary goal w ould be learned firs t, they would be more closely associated wi th the effect of " generalization of drive reduction , " making them stronger components of hab its than an ticipatory (or antedating) responses further removed in time from the goal . This suggests that false choices near a goal would be eliminated before false choices d istan t from a goal . Hull also predicted that this effect causes the a ttracting power of a goal to increase as the animal nears atta inment, because the closer res have stronger secondary reinforcement properties . This led H ull to m ake p redictions concern­ ing the relationship of goal attractiveness and d istance fro m the goal , using his concept of grad ient of reinforcemen t, very similar to those made by Lewin (Chapter 6) and M iller and Dollard (Chapter 7) . This mo del would predict that organisms engaged in obtaining food would become more eager (more highly motivated) the closer they came to being able to ea t the food . Also, habits close to eating food (such as grabbing the b i ts of food fro m the fee der) would be learned more strongly than in itial responses, such as bar- pressing to trigger a feeder mechanism, because they have been re inforced by the stronger con­ ditioned reinforcers closer to t he final d rive reduction . Why d id H ull add complex derived mechanisms such as re- S c ch ains? One answer is that by t he 1 940s, a variety of facts about learn ing had been discovered that could not be explained by j u s t the in tervening variables . Primarily , these were demonstrations by t he cogn itive theorists that knowledge of external inde­ pend ent variables such as re inforced (assumed to be d rive-reducing) trials was sometin1es insufficien t in p redicting and explaining the progress of the learning process . The re- Sc concept p rovided H ull wi th a mediating mechanism much like Pavlov' s second signal system or Guthrie' s movement- p roduced stimuli . This mechan ism was useful in expla ining learn ing which was not imme diately revealed in performance . Examples of such hidden or latent learning will be presen ted in C hapter 5 (cogn itive theories) . The rc- s c mechan ism can be u sed both to describe the chaining of extern al even ts (such as series of external cues and overt res ponses) and chain ing occurri ng pri marily wi thin the organism (which is similar to Guthrie's theory) . Today H ull's model of internal mediation is still im portant as a major al ternative to Skinner' s theory of chain ing of stimuli and re sponses (Hergenhahn , 1976) . Son1e problems with the rc-S1.; concept include researchers' fa ilure to find anticipatory chewing, s aliva tion, and other responses ( revi ewed in Hilgard and Bower, 1 975) , and Hull's confound ing of the drive and cond itioned re inforcer properties of Sc;S . Nonetheless, H ull made ingen ious use of the re- Sc conce pt in n1 any ways, includ ing his developn1 ent of the notion of the hab it- family hierarchy. H u l l s pec u l ated t h at org a n is m s e m i t fract i o n a l responses si m i l a r t o t h ose e m it ted i n t h e p resence of a g oa l ( s u c h as food ) w h e n i n a d r ive state . T h ese f ract i o n a l res g e n erate i n te r n a l cues (s(;s) w h i c h a c q u i re both second ary d r ive and c o n d i t i o n ed rei nforcer p ro pert i e s . T h e re- Sc c o n c e p t was evo ked to ex­ p l a i n l ea r n i n g c h a i n s of respo nses l ead i n g to g o a l s .

Thorndike a n d Hull

67

Habit-fa m ily h ierarch ies

The habit-family hierarchy is a p ri nciple a t the derived or interm ediate level in the same sense that the p ri nciple of " generaliza­ tion of d rive reduction" was derived from m ore p rimary p rinciples related to drive and habit. H ull used intermediate-level principles much like first- order p rinciples to predict depen dent variables and to generate further deductions, s uch as the p ri nciple that gradien ts of reinforcement operate as a function of distance fro m a goal . Similarly , the "hab it-family hierarchy , " w hich p redicts t he time a t w hich shifting from one habit to another will occur i n a p ro blem- solving situation, is deduced from more b asic principles . The habit-family h ierarchy principle is, i n tum , t he basis for further deduction s . A common observation i s that w e d o n o t always obtain a given goal i n the same way . From food getting to sex ual satisfact ion, we tend to learn alternative ways of moving from a start ing point to the satisfaction of a given n eed . These alternative habits m ake up a "family" of similar responses which a re inferred to be integrated by a common mechanis m . This mechanism is the fraction al an­ tedating (anticipatory) goal reaction ( re) , which leads to the goal stimulus (Sc) to which all behaviors are conditioned . The degree to which each response forms a connection with Sc is determined by the gradients of reinforcemen t . For exam­ ple, long routes through a maze, which are more remote fro m reinforcement (fo od ) , form weaker bonds than s hort rou te s . The result of this p rocess is that easy and q uick methods to obtain drive reduction are favored and less efficient responses appear only when the more efficient ones are blocked . This order of p referred alterna tive habits is the habit-family h ierarchy . H ull further deduced (Hilgard and B ower, 1975) that if one member of a habit-family hierarchy is reinforced i n a completely new situation , other members of that family (by association) will gain in reactive p o tential and may i n the future b e evoked by that situation . This deduction of response equivalence i n new situati ons offered H ull a means to explain non - trial - and-error, or insight, learning . An example of this p ri nciple might be a s tu dent's wri ting a paper . When a particula r tho u gh t is blocked, the s tudent goes to a similar one with the n ext h ighest associative value . Similarly, if students are unsure of a particular alter­ native on a multiple choice exam, they m ay select the answer with the next h ighest associative value, despite the second answer' s lesser pairing with the original information . H u l l s u g g ested t h at a l te r n ate sets of hab i ts re lated t o reac h i n g a p a rt ic u l a r g o a l a re a r ra n g ed i n a h a b i t-fa m i l y h i erarc h y . I f t h e so l u t i o n h i g h est i n t h is h i e ra r c h y i s i n effect u a l i n a g i ve n s i t u ati o n , t h e n e xt m o st p ro b a b l e r e s p o n s e c h a i n wo u l d b e e m i tted , a n d so o n .

Ch a nges in the Theory fro1n

1 943

to

1 952

Hull made several changes in the t heory p resented in 1 943 when he wrote A B eha vior System (1952) . One typ e of chan ge was the a d d i ti on of several new intervening variables . The two most important of these were K , or incentive motivation, and V, or stimulus intens ity dynamism.

68

The History of Learn ing Theory

Hull added the variable of K (K stands for Kenneth Spence, who was one of H ull' s coworkers [ Sahakian, 1 976] ) as a result o f a classic study by Crespi ( 1 942) . Crespi measured the run n in g speed of three gro ups of rats receiving d ifferent numbers of food pellets in the goal box . It was foun d that running speed was directly rela ted to the number of p ellets given . Th is result could have been explained as a function of greater amoun ts of reinforcement lead ing to a stronger habit through i ncreased drive reduction, which manifested itself i n faster run­ ning . The second part of this experiment, however, pro duced res ults that could not be so easily explained in term s of drive (D) and habit strength (S HR) . In the second part of the experim ent, Crespi gave all three gro ups of rats the same number of p ellets formerly given to the m iddle group . Under these condi­ tions, rats who had form erly received a small amount of food very rapidly increased their running speed , while those who had formerly received a large amount of food equally rapidly d ecreased their running speed . Since these shifts were much more rapid than the origi n al learning of the runn i ng respon se, Crespi concluded that amount of drive reduction alone cannot accoun t for learn­ ing, b ut it i nstead affects perform ance thro ugh som e type of motivational factor. Th is motivational variable, which is related to the organ is m' s experience of the amount of food encountered on the previous trial, was labeled K, or incentive motivation, by Hull . Hull thought that K is a function of the i ntensity of re (the fractional anticipatory goal response) which would be 'greater when the grea ter drive reduction prod uced by a larger reward generalizes down the respon se ch ai n . Greater res would produce stronger ses, which , of co urse , both induce secondary drive and have second a ry reinforcin g (drive - reducing?) p roperties . Thus, greater K was assumed to result in stronger stimuli conditions, which lead s to faster run ning . K was postulated to multiply wi th D a nd S 1 1 R to produce SER. It should be noted that the effect of K is on the excita tory potenti al (SER) and not on the strength of the S H R bond . H ull would use K to explain a p erson' s spending more effort preparing a meal if he were working with particularly desirable foods, or someone' s expending more effort i n tryi ng to date the more attractive of two possible d ating choices. V, or the intensity of the evoking stimulus, was a variable i nvented by H ull to explain greater res ponse rates wi th stronger stin1 u l i . V, l ike K, was assu med to multiply wi th D and S "R to produce S ER . A grea ter tendency to seek food after being exposed to a stron g odor of a desirable foo d compared to exposure to a weak odor of the same food might be an exa n1ple of the effects of V. As these and other intervening variables were added to expla i n poten tially disconfirm ing results, Hull's system became capa ble of explaining a wider ra nge of data, at the cost of beco ming increasin gly unwieldy. The basic outli ne of H ull' s variable system i n simplifi ed forn1 is shown in F i gure 3 . 3 . This fig ure outlines the rela­ tion sh ips of the variables, i nclu d i n g V and K . Another important change was in the nature o f D . The 1 943 theory had defi ned pri n1 ary (as opposed to secondary or condi tioned) reinforcement as dependent upon a reduction in the strengt h of D . The revised theory (Hull, 1 952) defin ed reinforcement as a process ei ther of the red uction in the stimuli pro-

Thorndik e and Hull

Independent Vari ables Hours of deprivation Aversive

D 1 ( D rive)

·

i s obta i ned

Size or I nten sity of R esponses

x

v (St i m u l u s i ntensity dyn a m ism) x

sti m u l i

N u mbe r of t r i a l s i n wh ich rei nforcem ent

STAGE II

STAGE I

(pa i n f u l)

Amount of rewa rd

Dependent Vari ables

Interven ing Vari ables

>

K ( I n ce n tive motivation)

�

x

�� =

SH R

� ( H abit strength) ·

-

( IR

+

_......-. sI R ) �

t

69

E S R

/

is t e r m i n ated . . (ext i nction response)

� Rate o r number

� '---- (Tendency not to respond-

( R eactive Tota l t r i a l s _. i n h ibition- l ike

or latenc ies

Responses given � after rei nforcement

(1ien d ency to respond to a cue)

Speed of responses

of responses

conditioned i n h ibition)

fatigue)

Figu re 3 . 3 The basic form of H ull's system . Th e indepen den t variables influ ence firs t-s tage in terven ing variables, w h ich determin e th e value of secon d- stage in tervening varia bles, whose effects will be m easu red from dependen t varia ble m easu res . A p lus or minus sign m eans tha t the effects of a particular in terven ing variable shou ld be a dded or sub tracted from o th er in ter­ v en ing variables in p redicting the fina l ten dency to respond. An " x " sign means that the variables so con nec ted must b e m u ltip lied by each other.

duced by a drive or of a decrease i n the strengt h of the anticip a tory g oal s timuli (sc) , produced by "little re, ' ' the fractional anticipatory g oal response . In addi­ tion , the amount of drive reduction occ u rrin g on each trial was no longer p ostu­ lated to i nfluence habit strength . Instead, only the number of tri als in which drive reduction occurred w a s considered . Amoun t of drive red uction per trial is of course dependent upon the m agnitude of the reward received by the animal on the p revious trial (K or i ncentive mo tivation being gre ater with greater reward s) . In h is 1 952 work, H ull remains a behaviorist only i n the sense that he assumed that his intervening variables h a d p roperties like those measu rable from overt behavi ors . M o st maj or p rinciples from 1 943 he revised to conform with new information . H u l l m ad e several i m p orta n t c h a n g e s i n h is t h e o ry b etween 1 943 a n d 1 95 2 . T h e s e i nc l u d ed add i n g t h e i n te rv e n i n g vari a b l es o f i n c e n t i ve m ot i vat i on ( K) a n d st i m u l u s i n te n si ty d y n a m i s m (V) a n d rev isi n g t h e d e f i n i ti o n of rei nforce­ m e n t f ro m t h e res u lt of a red u ct i o n i n d r i v e stre n g t h t o t h e resu l t of a red u c­ t i o n i n t h e i n t e n si ty of t h e sti m u l i asso c i ated w i t h a d r i v e ( e i t he r p r i m ary o r c o n d i t i on ed ) .

H ull's theory was also modified by the efforts o f h is followers and students . Miller' s n eo- H ullian theory will be reviewed i n Chapter 7 . Spence p roduced a

70

The H istory of Learn ing Theory

rev1s1on of H ull' s theory which follows H ull's method of theory cons truction very closely . Th is revised theory illus trates the process by which the followers of maj or theorists change those theories to make them more flexible and move them toward s the mainstream of learning theories . We will now review so me of Spence' s contrib utions to the Hullian tradition .

Spence's Con trib u tions to Hullia n Theory S pence is perhaps the best known of the neo-Hulli an s and the most closely identified with the H ullian approach , characterized by the derivation of inter­ vening variables which are organized into equations designed to p redict re­ sponse variables . Spence' s work helped sh ape H ull's 1943 theory, and Spence' s later suggestions can be seen in some of the ch anges in H ull' s 1952 theory . Spence wrote the foreword to the 1952 volum e, and in 1 956 was still working wi thin the H ullian tradition (Sahaki an , 1 976) . L i ke H ull, Spence attempted to reduce the complex phenomena described by the cognitive theorists to basic mechanisms . This reductionis tic emphasis can b e seen in two classic papers (Spence, 1936, 1937) in which Pavlovian principles of conditioning, extinction, and stimulus generalization were used to explain both discrimination and " relational" or transposition al learning . Essen tially, Spence argued , when a stimulus is reinforced , it builds up an exci tatory ten­ dency, while an inhib itory potential builds up around un rewarded stimuli, thus producing discrim ination learning . Both these excitatory and inhibitory tend en­ cies h ave generalization gradients (this whole argument is very similar to Pav­ lov's theory presented in Chapter 1 ) . If an animal is trained to choose the larger of two circles and then is tested with a n ew pair of circles in which the smaller circle is now the same size as the formerly reward ed circle, the animal will us ually choose the new, larger circle and ignore the form erly reward ed circle . Cogn itive theorists claimed that s uch results p rove the animal learned the " idea" of larger . Spence demurred , cleverly demons tra ting that the Hullian appro ach co uld handle s uch res ults as follows : Assume that b oth of the origi n al circles produce generalized reaction tendencies-one excitatory and the other inhib itory . Tendencies to emit or inhib it responding form general ization gra­ dients, with the tendencies being directly proportional to the extent to which new circles are similar to the origi nal circles in size (the organism would show maxi mal exci tatory and inhib itory tendencies to the ori ginal rewarded and un­ rewarded circles, respectively, wi th lesser tend encies to new circles very similar to these in size and still lesser tendencies to more dissimilar ci rcles) . Further assume that the inhibi tory generalization gradient of the un rewarded circle overlaps that of the rewarded circle. As a fi nal assum ption, assume that the generaliza tion o f excitation associated wi th the rewarded circle leads to a ten­ dency to respond to circles still larger than the form erly rewarded circle. Then , if the s um of the inh ibitory and exci tatory potentials for the formerly rewarded circle was less than the generalized excitement for the new larger circle, the anin1 al would choose the larger circle. The hypothesized relationships of the generalization gradi ents are shown in Figure 3 .4 ( H ilgard and Bower, 1975 ) . S pence was also ins trumental in pers uading Hull to adopt the incentive mo tivation construct, or K . Even tho ugh Hull's 1 943 theory was based on habit

Thorn dike a n d Hu ll

71

+-'

c (1)

+-'

0 a.. >. .._

0

>---->.---

+-'

..0 ..c c

N et exc itatory potential to t h e fo r m e r S +

.._

0 >. .._

0

+-'

>-»---

ro

+-'

() x w

N et exc i tato ry potent i a l to t h e new c i rc l e

s+

ro

�

C i rc l e Area

Figu re 3 . 4 The hypoth e tica l gen eralization gradien ts for inh ibitory (dark lin e ) and excit­ a tory (dotted lin e ) ten dencies for th e formerly un rewa rded circle (S ) , the form erly rewarded circle (S + ) , and net excita tory ch a rge for th e n ew circle (S n ) . Th e inh ibitory p oten tia l is shaded. -

and drive as the determiners of response tendencies, Spence postulated that an incentive or "eagerness for the goal" variable was i nvolved in control of perfor­ mance . S pence was also the first to relate K to the fractional an tici patory goal­ respon se (re) variable, which was seen as the classically conditioned response causing the animal's excitement at an early point in a long instrumental re­ sponse chain . In postulatin g his K variable, Spence moved away from H ull's d rive reduction position stated in the 1943 theory and i ncorporated contiguity as an important element in the development of a condi tioned response . In Spence' s word s : The h ab i t s trength ( H) o f the instrumen tal response, i t i s i m portant to note , is assum ed to be a function of the n u mber of occurrences of the response ( NR) in the situation and to be q ui te in dependent of the occ u rrence o r non-occurrence of a reinforcer. Thus, if the response occurs there will b e an increment in H regard ­ less of whether a reinforcer does or does no t result. Th is assumptio n , it is apparent, makes this formulation a con tigu i ty and not a re inforcement theory . And yet the theory, a s is clearly evi dent, i mplies tha t the exci tatory strength (E) of the response i n such in stru mental learning situations does d epend u pon the occurrence and p roperties of the re inforcer. [Spence , 1960, p. 96]

This change fro m Hull' s p osition meant that the basic eq uation for the tendency to respond must be d ifferent. Spence' s formula became

as compared to H ull's

Thus, for Spence, the p resence of either an incentive or a d rive s tate co uld lead to the performance of a response . For Hull, both drive and i ncentive were neces-

72

The History of Learn ing Theory

sary . Another difference in Spence' s equation (Sahaki an , 1976) was the new inhibitory variable of IN, which was a frus tration variable res ulting from non­ reinforcement rather than H ull's fatigue-like I R . IN requ ired previously rein­ forced trials to occur and could also be b uilt up fro m delays in re inforcement. Spence's changes in H ull's theory put Spence in the p osition of a con tiguity theorist on learn ing, a reinforcement theoris t on performance, and an almost Tolman-like cognitive theorist on anticipation and frus tration . This movement towards a more eclectic theoretical base was typical of most of the neo- Hullians . B y maki ng his changes, Spence extended the viab ili ty o f the H ullian approach after Hull's death .

Hull's Positions on Major Iss ues Na ture/n urture Hull accepted the assumption that there are some inborn tendencies to respond in specific ways to drive s tates (B olles, 1 975) and Darwin ' s ideas about the importance o f adaptive mechanisms . In spite o f this, h i s theory is strongly b iased towards seeing learn i ng thro ugh environmen tal influences as more important than innate factors .

The ho1v of learning

Hull was adamant in h is later theorie s i n insisting t hat no learning could occur without reinforcement. The critical variable in learning, he held, is the number of reinforcing trials . Re inforcemen t is a process of drive reduction (1943) or of a reduction in the intensity of s timuli associated with a drive (1952) .

The 1vh a t of learning

Although Hull was a connectionis t, he d id not see the b asic un i t of learn ing as that of connecting tiny muscular twi tches to s timuli . H ull was a " molar" be haviorist; h is basic unit of learn ing w as the complex habit. H ull never discussed cognition d irectly, but he did attempt to explain co m­ plex " insight" learn ing by his " p ure stimulus acts, " or re and sG variables, w hich provide a type of anticipation mechanis m . The habit-fa n1ily h ierarchy offers an explanation for using past experience in new situations wi thout direct trial and error. In spite of these complex v ari ables, Hull was as mech an istic as Thorndike and as connectionist as any behavioris t.

Contin uityln onco n tinuity , use of a ni111 al da ta , a nd deten11 inis111

H ull saw habit s trength as b uilding up gradually as a function of the number of re inforced trials . He freely used data from an imal studies, and he saw be havior as deter­ mined by environmen tal events and the state of h is intervening variables within the organis m . Near the end of his life, he voiced so me reservations about so me of h is laws derived " fro m the study o f hun gry ra ts" being fully applicable to human be havior ( in Bolles, 1 975 ) .

Perspective H ull began h is work with a strong background in human research . His origi nal plan had been to write three maj or books on learn ing : a volume on primary principles, a volume on indiv i dual nonsocial behavior, and a conclud ing vol­ ume on social or gro up behavior and applications (Sahaki an, 1 976) . As we have

Thorn dike a n d Hull

73

mentioned, H ull died shortly before the second volume was p ublished . With h is dea th went the hope of the application of h is principles to com plex human problems in the rigorous experimental manner characterizi n g the developmen t of h is p rinciples . O ddly, for a psychologist who had initially concentrated on human research , H ull tested h is 1 943 theory mainly on rats . In contrast to Thornd ike, who spent much of h is career suggesting uses for h is principles in schools, Hull died before he felt h is the ory had been completed to a level appro ­ p riate t o the advocacy of extensive human applic a tions . On a molar level of explanation, however, Hull's cons tructs have some value i n explainin g co mplex phenomena such as insigh t . When he tried to predict specific q uantita tively measured outcomes for individual organisms, i t became apparent that h is sys­ tem was generalizable for only a few types of rat experiments . In h is attempts to measure precisely units of motivation ("mots" ) , and hab i ts ( " h abs") on a cen­ tigrade scale, he los t sight of the larger task of general learning theory develop­ ment and application ( Hilgard and Bower, 1 975) . Too many parameters had to be measured, and too much arb itrary assignment of values to the intervening variables was necessary . While many o f H ull's constructs, s uch a s "little rc- sc" a n d the habit-family h ierarchy, have continued to be useful, other key principles have not survived the test of experimental analysis . The findings by Sheffield and Roby (1950) that rats would work for sacch arin ( a sweet nonnutritive substance) even though no drive reduction resulted s truck at the heart of the concept of all reinforcement as dependent upon reduction in the cues associ a ted with a drive . H ull coun tered, however, by suggesting that because swee t tastes had in the p a s t been asso­ ciated with drive reduction, swee t taste could h ave become a sc w h ich , through i ts secondary reinforcing properties, reduced hun ger tension cues for a brief period ( H ull, 1952) . Perh aps Hull's theory m ust be evaluated on term s other than considerations of accuracy and generalizability . Perhaps it might better be evaluated in terms of i ts infl uence on the thinking of o ther learning theorists . Hilgard and Bower (1 975) report that in the Jo u rn a l of Exp erim en tal Psych ology and the Jou rn a l of Co mpara tive a nd Ph ysiological Psychology in the years b e tween 1 941 a n d 1 950, 70 percent of all studies in the area of learning and motivation referred to Hull's books and papers . M any of the dominant figures in the field of learn ing, i nclud ­ i n g Miller, Mowrer, Amsel, Spence, and Hilgard, were either Hull's s tudents or associated with him at Yale (Sahakian, 1976) . No one else in the h is tory of learning theorists has s timulated so much research and so much pro d uctive theorizing ! Chapter Perspective

Today, the work of Thorn dike is of interest p ri marily for i ts infl uence on the developmen t of more recent theories, and the work of H ull can be interpreted a s a grand , if somewhat futile, blind alley i n the h is tory of trying t o unders tand learn ing . The work of the theorist to be reviewed in the next chapter ( Skinner) is current, controversial, and compelling . Skinner i ncorporates an environmen­ talism almost as radical as Watson' s, an ingen u i ty in developing experimental

74

Tlze History of L ea rn i ng TJz eonJ

appara tus perhaps exceeding Pavlov' s, a propensity for s u ggesting applications as great as Thorn dike's, and a co mmitment to research as great as H ull' s . Key Terms belongingness

independent variable

m ol ecular

conditioned inhibition (S 1 R)

intervening variable

oscil lation function (S 0 R)

law of associative shifting

p ostulate

law of effect

r e -generated stimulus (s c )

law of exercise

reactive inh ibition (I R )

law of multiple response

rem iniscence effect

law of prepotency of ele­ ments

stimulus intensity dynamism (V)

law of readiness

surplus meaning theorem

goal response ( R e )

law of response by anal­ ogy

g oal stimulus (S c )

law of set (attitude)

habit-family hierarchy

mechanistic

habit strength (S 8 R )

mentalism

dependent variable d eclining returns drive

(D)

equipotentiality excitatory p otential (S E R ) fractional anticipatory g oal reaction (r c >

incentive m otivation

(K)

transfer trial and error ' truncated law of effect

m olar

A nnotated Bibliogra p hy

Although ideally one needs to read several of these theorists' works to cover the changes in their thinking, the followi ng sources should be helpful : ( 1 ) E . L . Thorndike, Edu ca tion a l psychology: Th e psychology of learn ing , vol . 2 ( New York : Teachers College, 1913) . (2) C . L . Hull, A b e h a vior syste m : An in troduction to beha vior th eory concern ing tlze individual org a n ism ( New H aven , Conn . : Yal e U n i­ versity Press, 1 952) , somewhat hard readin g but no more so than any other of H ull' s writings; (3) W. F. H ill, Lea rning; A s u rvey of psycho logica l in terpreta tions, 3rd ed . (New York: Thomas Y. Crowell Com pany, 1977) , a good seconda ry source that is easier reading than the previously ci ted pri n1ary so urces .

Skinner : R einforce m ent or O perant Conditioning

Today, Skinner' s operant theory of learn ing has become to reinforcement theory what Pavlov's work was to con tiguity app roaches-a blueprin t of learning ex­ p ressed as experimentally verifi ed laws which provide the basis for a wide range of practical applications . Yo u will read abo u t Skinner' s experimental metho d s, his incorporation of classical conditioning pri nciples i n to his theory, h is basic p ri nciples, and h is critical work on the effects of different p a tterns of giving reinforcemen ts . Just as most of the basic terms and principles Pavlov developed remain importan t to understanding s ubsequent connectionist theories, so are Skinner' s principles essential to un derstan ding the current appro aches to rein­ forcement theory to be presented in Part 2 of the text . Especially, you should understand the effects of the four basic types of schedules of reinforcement on b o th rewarded p erformance and on performance duri n g extinction . The control of behavior by rewarding or reinforcing circumstances, the pattern ing of re­ w ards to infl uence the frequency and intensity of responses, make up the maj or emphasis of Skinner' s theory about learn ing . B urrhus Fre deric S kinner (1904 -

)

Bro ught up i n Susquehanna, Pennsylvania in a clo se , devoutly religious fam i ly, Skinner earned his B . A . i n English at nearby Hamilton College . He went on to write short stories that earned the praise of the poet Robert F ro s t and moved to Greenwich Village, an artists' a rea of New York C i ty . Six months l ater, Skinner determined that the ideas expressed i n h is wri ting were trivi al com pared to the ideas of Pavlov in Conditioned Refiexes (1960) and of John Watson, as discussed by Bertrand Russell . Deciding h is writing was nothi n g b ut "penci l craft, " he went back to college ( Harris, 1971) . He was admitted i n to Harvard , studied under p sychology's foremost h istorian , E dwin B oring, s ub mi tted a thesis on reflexes, and was granted a Ph . D . i n 193 1 . He b egan teach i ng a t M innesota, moved up to the chai rmanship and professor ran k a t Indiana in 1945, and in 1948 return e d to Harvard and never left (Sahakian, 1 976) . In 1938, Skinner p ublishe d a book on the empirical descri ptive laws of learn ing as observed in rats and p igeons ( The Beha vior of O rga nisms ) . In 1 948, he extended these laws to the b ehavior of persons and societies in h is novel Wa lden Two (written in seven weeks) . He presented h is p ri nciples in a more scholarly format in S cience a nd H u m a n B eha vior (1953) . Although the b asic laws rem a in

76

The Histon1 of Lea rn ing Theory

essentially unchanged from that time, he has extended their applicati on in The Tech nology of Tea ching (1 968) and has explored the theory of his " nontheory" in Con tingencies of Reinforcement, A Theore tica l A n a lysis (1 969) . In 1 971 , he clarified h is essential philosophical assumptions wi th Beyon d Freedom and Dignity and summarized his work and replied to his critics with Abou t Beha viorism i n 1974 . In a sense , he completed the process of beginning with general l aws, progress­ ing to prediction of individual behavior, and finishing with a wide range of human applications which Hull had tried and been unable to finish . Skinner then went on to explore the philosophical implications of his the ory . Skinner h as been consistent in h is d islike of i nner causes ( such as motives, ego states, habit strength, and so on), and today argues about and applies h is ideas wi th intensity and clear prose . He use d his invention of the air crib ( a temperature-controlled enclosed crib) i n raising h is daugh ter and , through ap ­ plication of o perant learning principles to h is own behav i or, h as maintained h is own enormo us writing productiv i ty ( Harris, 1 971) . Skinner was infl uenced towards painstakin g exp erimentation by Pavlov and was introduced to radical behaviorism by Watson . He beli eves in science as a set of a ttitudes which facilitate observation and experimentation ( instead of accepting the ideas of so-called authori tie s) . Th is philosophical stance carries over i nto h is strong emphasis on obj ectivity and the accep tance of exp erimental data, even when it is contrary to one' s own wishe s . His atheism is part of h is general rej ection of seeing causation as the result of unobservable inner forces . I nstead, he has committed himself to tryin g to de termi ne forces in the environ­ ment which control behavior. Skinner does not deny that inner forces m ay sometimes control behavior or that the ten dency of all sciences to seek inner causes has son1etimes had useful results . Ra ther, he has sought to avoid such theorizing himself, on the gro un d s that unobservable events may tempt the scientist to assign properties and functions wi tho ut adeq uate j ustifica tion . He note s : "The motion of a rolli n g stone was once attributed to its vis viva [ ro ughly , life force] . . . " (Skinner, 1 953 , p . 27) . I n his advocacy of an obj ective scientific methodol o gy, Skinner was follow­ ing Watson's rej ection of inner agents and d irectly attacki n g Hull' s (and others') appro aches of tryi ng to predict and un derstand behavior on the basis of inferred internal processe s . He dev iated from the views of Wa tson, however, in his willingness to accept thought and other private behav i ors as so urces of data, insofar as they are revealed through verbal and other objective res ponses . In this respect, his views are not in conflict with the phenomenological appro ach of trying to unders tand inner behavior by as king s ubj ects about the ir experiences (Day, 1969) . It was only inner causes that Ski nner avo ided inves tigating or theorizing about, on the gro un d s tha t the ultimate cause of inner behavior could be traced to environ mental infl uences . Th is rationale for h is " black box" or "empty organ ism" appro ach to the study of behavior was directly opposed to the pract ice of sp eculating about hypothetical constructs or intervening variables wi thin organisms . One of the reasons Skinner decided to focus on environmen tal rather than on inner events was the richness of i nform ation ava il able for a scien tific analysis of the de ter-

S kin ner

77

minants of behavior. This type of i nformation induded b oth variables p resent in the organism's immediate environment an d variables related to the or­ ganism's h istory . Skinner felt that these types of independent variables could b e investigated using the usual tools of science. He conceded that such variables might influence behavior in subtle ways but believed that no adeq uate accou nt of behavior could be p ossible witho u t inves tigating them . H is goal was to develop a method o f a n alyzing the function of environmental events in deter­ m ining and pred ictin g t he behavior of organisms . Skinner' s method o f investigating t he external variables controlling behav ­ i o r w as w hat h e called a causal o r function al a n alysis . H i s d ependent variables were the effects of these external variables or the changes in behavior caused by them . His goal, thro u gh this method of analysis, was the prediction and control of the depen dent (behavioral) variables . For Skinner, the l aws of behavior are the cause - an d -effect relationships between his independent vari ables (extern al environmen tal events) and h is resp onse (dependen t) v ariable s . He believed that a synthesis of these laws in q uantitative terms yiel d s a comprehensive pictu re of organis ms as behaving systems . This approach to t heory b uilding was very d ifferent fr om that of Hull and others, which postulated that caus ation also i nvolved the i nternal mediating variables assumed to exist w i thin organisms . Skinner h ad no n eed for variables such as drive and i ncen tive m otivation be­ cause he saw speculation about such variables as simply unnecessary to a sci­ ence with the goals of p redicting and controlling behavior.

S kin n er's Approach to the Con tiguity /Reinforcen1ent Issu e Although Skinner was radical i n seeking caus ation i n the environment, h e w as flexible i n h is p osition on the hows of learning. He w as very familiar wi th Pavlov's research and with the principles of classical con d itioning. Rather than rej ecting a contiguity mechanis m of t he type described by Pavlov , he postulated that two distinct types of learning exist. In the first or Pavlovian typ e, a previ­ ously neutral stimulus acquires the p ower to elicit a response which was ori gi ­ n ally elicited b y another stimulus . The change occurs when the neutral stimulus is followed or " re inforced" by t he US . Skinner saw this type of condi tioning as important in modifying visceral (gut) and o ther p rimitive responses of smooth muscle and glan d s . Since these p rimitive response systems are so i mportant i n emotion and motivation, Skinner made this type of condi tioning (classical con­ ditioning) the means by w h ich new stimuli could come to elicit emotional or motivational sta te s . This was i ncorporated into h is theory as the basis for t he power of sec ondary or conditioned rein forcem ent. His use of association p rinci­ ples in explaining second ary reinforcement is very similar to the approach taken by Spence and m akes Skinner's theory of learn ing a two- factor t heory . In spite of his reluctance to postulate unobservable inner events as c ausing behav i or, Ski nn er explained working for delayed reinforcement or completing long re­ sponse chains in terms of inner responses leading towards a goal and generating stimuli which b ecame classically conditioned to p rimary reinforcers . For hu­ mans, such inner cues and responses " are cert a in verbal consequences supplied

78

The History of Lea rn ing Theory

by the man i tsel f . . . " (Skinner, 1 953, p. 77) . Conditioned reinforcers paired with more than one primary rein forcer he labeled generalized re inforcers, m ore powerful than any cond itioned reinforcers tied to only one type o f deprivation s tate . . . . if a cond itioned reinforcer has been pa ired wi th reinforcers appropriate to many condi tions, at least one appropri a te s ta te of d eprivation is m ore likely to preva il upon a la ter occasion . A response is therefore more l i kely to occur . When we reinforce wi th money, for example, our subsequen t control is rel atively independen t of momentary d epriva tions . . . . We are automa tically reinforced , apart fron1 any particular depriva tion , w hen we successfully con trol the physical w orld . Th is may explain our tendency to engage in skilled crafts, in artistic creation , and in such sports as bowl ing, billiard s , and tennis . [Skinn er, 1 953, p . 77]

Thus, Skinner uses a contiguity principle to provide a p owerful explanatory device for behaviors which seem unrelated to immediate reinforcemen t . Skinner s a w classically conditioned respon ses as elicited b y environ men tal cues in an automatic fashion . Hence, this type of condi tioning he also labeled respondent or type S (stim ulus - type) conditioning . According to Skinner, " the respon ses and attitudes evoked by pretty gi rls, babies, and pleasant scenes m ay be transferred to trade n ames, products, pictures of pro ducts, and so on" (1953 , p . 57) . (Herein lies the explanation of J ohn Watson ' s s uccess at advertising with h is "L ucky Strike green has gone to war. ") While paying due respect to Pavlov's methodology and principles, Ski nner saw respondent or typ e S conditioning as of l i m i ted i n teres t. His primary con ­ cern was wi th overt behavior that h a d an effect on the s u rro und ing world . I n this type o f behavior, the conseq uences of the be havior " feed back" i n to the organism and m ay modify the probability that the behavior which pro duced the conseq uences will be repeated . When a conseq uence acts to i ncrease the proba­ bility of the reoccurrence of a response, i t is said to act as a reinforcer and the act of del ivering that conseq uence is called reinforcement. In Skinner' s theory , a re inforcer is anything that increases the probability of the reoccurrence of a response; h is defini tion is m ade entirely in terms of be havioral operations and does not involve in ternal entities s u ch as drive or mo tivation . This type of condi tion ing is called opera nt conditionin g because the organism operates on its environn1ent, or instrumental conditioning because the responses are instru­ men tal in bringing about a conseq uence . Opera n t cond i tion ing differs from responden t (classical) condition ing in that most responses are not con sid ered to be el icited by stimul i . From Ski nner' s p oint of view, the alleged " s timulus" for an operant is sim ply no t observable in n1o s t case s . O perant behavior is thus considered to be spon taneously e mitted by the be having organ ism . Th is ap­ proach avoids a ttemptin g to identify an1b iguo us stim ulus events . Recall the d i fficulties, d iscussed in Chapter 1 , encoun tered by Pavlov in creating research condi tion s under w hich he co uld be reasonably confiden t abo u t the " true" CSs and USs . An opera nt m ay, however, and often does, acq uire a relationship to a p ar­ ticul ar stimulus, a nd its occurrence may even be partly controlled by that s timu-

S kin ner

79

lus . In these cases the s timulus is called a discriminative stimulus ( 5 0 or S + ) ; this stimulu s serves t o signal the organism when re inforcemen t for the emission of a specific operant is h ighly probable . S i nce the S0 is now t he signal for t he occasion for the operant behavior, the operant is referred to as a dis c rim inated operant . The stimulus, however, does not elic i t the appearance of the respon se , a s in the case of a Pavlovian reflex . S0s serve to g ui de behavior; a n d will b e further d iscussed in a later section on fixed ratio schedules a n d response chain s . They are also the basis of d iscrimination learning when combined w i th stimuli (S - or S cr Q) .._

Soc i a l a t t r a c t i o n s

+-' .._

+

0


ut the effects of ins tructions on influencing cogn itive sets conducive or noncon ducive to the d evelopmen t of helplessn ess . Seligm an found that helpless stu d en ts d i d not change their ratings o f the expectancy of success in problem situ a tions as the result of either s uccess or fa ilure . They see med to have learned tha t they could � ei ther predict success nor create it. This was in terp reted by Seligman as showing that the studen ts had learned that there were no con tin genc ies between the cues (CSs?) ava ilable to the studen ts and feelings of success (USs?) . This led Seligman to conclude that si tua tions in which the subj ec t could not predict USs from CSs were not situ a ­ tions i n whic h no cond itioni ng takes place, as postulated b y R escorla . Rather, he thought that the subj ects learned tha t they were helpless even to predic t o u t­ comes, let alon e con trol them . Vi ewed in this light, Rescorla's posi tive predic­ tion dogs had learn ed to predic t s hock durin g Pavlovi an cond i tioning. After learn ing, they could so metimes escape shock in the shu ttle box train ing situa­ tion ; they were able to s how those adaptive res ponses in the presence of the CS whic h signaled shock during the critic al tes t day . The dogs in the negative pred ic tion group had learned when not to expec t shock ( learn ed safety) , and they respon d ed to the CS on the cri tical test day by reducing hurdle j umping. The dogs in the " truly random" con trol group , however, had learned tha t the ir responses were in depend en t of shock (learned helplessn ess) and so did not alter their ju m p ing ra tes on the tes t d ay . Sel i gman suggested ( 1 969) that the dogs in the " truly random" control group should have been experienc ing the most anx­ iety, or arousal, as a result of learn ing tha t they were helpless . In examin ing dogs given t he " truly random" procedure, Seligm an ( 1 975) found evi dence for ulcers and chron ic fear reac tions . Seligman ( 1 975) has proposed a general model of learned helplessn ess in *

O nce the con d i t i oned n e u rosis w a s e s t a b l ished , Pa vlov's d ogs beca m e u n a b l e to make d is ­

cri m in a t i on s th a t once were easy for them . A s i m i la r e ffect h a s been o b served b y S e l i g m an h el p l ess d ogs .

( 1975)

in

Advan ces in Classical Con ditioning

213

w h ic h cues provide informa tion abo u t con tingencies ( positive pred iction , nega­ tive prediction, or no prediction), whic h then interact with the subj ec ts' expec­ tancies (or beliefs or learn i n g about how helpless they are in a given type of sit uation) . This, i n tum , determines if and how they may respond . He h as also proposed a general theory of how to deal with learn e d helplessness (and the depression which usually goes with i t) in a w i de range of organ ism s . He sug­ gests (and has conducted research supporting th is v iew) that prior experience with successful control can "immun ize" organ isms against the h armful effects of con d i tions tha t usually produce learne d helplessness . He has also suggested that once learned helplessness develops, it can be reversed by forcing the subj ect to control o utcomes success fully . For example, he was able to reverse learned helplessness in dogs by dragging them over the hurdles of a shuttle box to escape shock, although from 25 to more than 200 draggings were necessary before the animals learn ed to respond on their own . Seligman has proposed that classical conditioning procedures can be distin­ guished from operant conditioning procedures by the fact that subj ects are unable t o control their exposure t o CSs and U Ss in classical conditioning. Learned helplessness occurs when t he subjects generalize their learned lack of control to situations where t hey could learn adaptive responses.

The issu e of n1edia tion

A s Seligman's a n d Rescorla's work h as made clear, the q uestion of the " how" of classical condition ing is still unresolved . Rescorla thinks that subj e c ts learn about the con tingencies relatin g the CS to the U S , and Seligman has suggested that subj ects learn expectanc ies or beliefs . W hen vari­ ables such as beliefs act to influence the process of learn ing, they are said to mediate between s timuli and responses . Many researchers h ave trie d to investi­ gate the role o f such me diating variables, whic h can be operantly cond ition e d skeletal m uscle responses or cognitive variables . L e t us now exam ine, i n some detail, a few studies which h ave investigated mediating variables, to show you the methods employed and the problems involved in in terpreting the results . W hitehead, Ren ault, and Goldiamond attempted to address d irectly the problem of medi ating variables . To con trol for cogn itive mediation , the subj ects were asked to think of various things, and measurements were made of stomach acid secretion during various types o f thoughts suggested by the experimen ters . To evalua te skeletal m uscle mediation , the electromyographic potential (EMG) o f the m u scles over the stom ach ( diaphragm m u scles) was record e d . By using a DRH ( differential rei n forcement of h igh rates) sche dule with money reward in a biofeedback p aradigm , they were then able to i ncrease acid secretion threefold i n three o f their four subj ec ts . When the schedule was switched to a DRO ( differential reinforcemen t of other than h i gh secretion) sche d ule, the three suc­ cessfu l s ubj ects were a ble to brin g secretion rates back to b asel ine ( pre­ b iofeedback) levels . The DRO schedule was much more successfu l than simple extinction proced ures . One subj ect m a in tained the threefold increased level of secre tion even after 1 1 d ays of extinction . The problem with interpreting these results as showing pure ins trumen tal cond i tion ing of a response m e d ia ted by

2 1 .J

lv1 o dcnz Con ten ders

the au tonom ic n ervous system was that both striate m uscle (voluntary m uscle) and thought p atterns wer� correlated with the changes i n secretion rates . The au thors noted that the patterns of correlations varied o ver subj ects; within sub­ j ects, they varied over time . Whitehead and colleagues (1975) concluded that they had demonstrated true operan t con trol of an autonomically controlled re­ sponse, but that their subj ects were l ikely to "b ring into play a variety of physio­ logical and other mech anisms that help m ain tain and prod uce the response required for the rei n forcer to be delivered" (Whitehead et al. , 1975 , p. 155) . Since subj ects' verbal reports on the cogn itive strategies employed were re­ ported as inconclusive, it appears possible that the results were produced by mediating mechanisms rather than by true instrum en tal cond ition i n g . While the research o n the issue of demonstrating th a t both instrum ental a n d classical cond itioning occur through contingency (rein forcem ent) m echanisms rem ains equivocal, what of the issue of awareness of contingencies raised by Rescorla's pred ictive hypothesis? Two recent studies by Biferno and D awson on autonom ic cond itioning in human subj ects have strongly supported the cogn i­ tive, or expectancy, aspect of the predictive hypo thesis . These researchers h ave worked with i n the fram ework of the psychophysiological orientation . " Psychophysiological observation is as old as the first youn g m an who noted a women's blush . . . . A men tal state was in ferred from a well defin ed physi o­ logical change (increasin g blo od flow to the face}"' ( H assett, 1978 , p. 1 ) . Psychophysiology is the science o f stu dying the effects o f m an ipulating behav­ ior (its independent variables) on chan ges in physiological states (its dep en d ent variables) . H assett (1978) notes that since the body us ually responds as a u n i t, some sort of medi ation is to be expected in cond itioning physiological states . Thus, this d iscipline would be expected to be oriented to investigating the iss ue of mediation i n classical con ditioning. In the first study revi ewed , Biferno and Dawson (1977) fo und that classical conditioning of the first component of the skin con ductance response (com ­ monly referred to a s the galvanic skin response, or GSR , b y n1 ost psychologists and as the electrodermal response by psychophysiologists) occurred only a fter their college stu d ent s ubj ects reported awareness of both the positive (CS + ) and negative (CS - ) contingencies . In all the ir subj ects, signs of cond ition ing of the first component GSR appeared suddenly, consis tent \-Vi th the cogn i tive interpre­ tation of the CSs acqu iring its pred ictive power as a result of an insigh t process . Controls employed by the authors included embedding the con d itioning para d igm with in a m asking task to d elay the onset of awareness so tha t pre- and postaware trials could be analyzed , and using th ree ways for subj ects to report awareness (this was to con trol for the possibility that the appearance of the CR was in so me way an artifact of the report ing procedures) . Reporting proced ures used were a spring-loaded d ial with seven buttons labeled with varying degrees of certain ty of when the subj ects expected the occurrence or omission of the US (a lou d noise) as well as verbal reports of expectanc ies, including "why" the subj ects expected the US or its omission . Du ring extinction trials, extinction occurred only in subj ec ts expressing their expectation tha t the CS would not

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occur. There was a p oten tially importan t complication, however . The a uthors also measure d a secon d , longer-latency "secon d component" skin conductance response . (An importan t contribution of psychophysiologists and o thers inves­ tigatin g the responses normally condi tioned using a Pavlovian paradigm has been to s how that most such responses consist o f different components whic h may be affected in different ways during cond ition ing . ) For some subj ects, this "second com ponent" appeared suddenly with awareness ( d iscontinuous or i n ­ sightful learn ing) , while for o thers, i t app eare d slowly as a function o f the number o f pa irings of CSs and the USs . Thus, the apparent contra d iction be­ tween the results o f Furedy and Schiffmann ( 1973) , wh ic h d i d not support the Rescorla hypothe sis, and the m aj or trend of Biferno's and Dawson's ( 1 977) find ­ ings m ight be explained by suggesting t h a t some components o f the GSR are more l ikely to be cond itione d due to contigu ity fac tors and tha t others depend u pon cogn itive , expectancy- based mediation . The secon d study by Biferno and Dawson ( 1 978) supports the view j ust expressed , that the Rescorla hypothesis m ight hol d for most au tonom ically con ­ trolled responses a s well a s for skeletal muscle responses con trolled b y the cen­ tral nervous system . In this stu dy, subj ects were informed of the relationship be tween color of l ights turned on for 7 seconds (one color the CS + and another the CS - ) and the US (shock occurrence or omission) . Halfway through the con d itioning trials , a ligh t of a th ird color was turned on . Half o f the subj ects had p reviou sly been informed about th is novel s timulus and h al f had not. After this light was turned on , the uninformed subj ects reported greater uncertainty about the contingencies between the CS and the US . This was accompanied by a decrease in their long-latency (secon d component) cond itioned skin con ­ d uctance responses, which is congruen t with Rescorla's ( 1966) report o f a l ack o f con d itioning i n his " truly random" control group, where the dogs were pre ­ sumably uncertain o f the contingencies between C S and U S . N o such changes, however, were observed in conditioned vasomotor resp onses ( p ulse volume act ivity recorded from the Ii ttle fingertips o f the subj ects' left hands) . F urther, the short-latency ( first com p onent) skin response increase d on the first uncer­ tain ty cue trial for the u n i n formed subj ects, showing that u ncertainty i tself may serve as a US for some autonom ically m ediated resp onses ( perhaps as part of an orienting or arousal reflex to n ew informa tion) . As we noted i n the d iscussion of Seli gman' s work, uncertainty by i tself may be stressful and may result i n learned helplessness rather than the learning expected . Stress a n d arousal, whic h have been implicated as important variables in classical con dition ing in some physiological s tu dies on animals, may operate as m e d iating variable s . Wilson , Simpson , DiCara, a n d Carroll (1977) foun d removal o f t h e a drenal glands of rats (whic h are the glands presumed to chem ically media te anxiety or stress related resp onses) facilitate d both simple and d iscrim inated Pavlovian con d itioning of reduced heart rate s . These results support the theory that arousal-related variables may con found interpre tations o f Pavlovian cond ition ­ i n g . Further, as was mentioned in several o f the s tu dies reviewe d , and as con­ cluded by H all ( 1 976) in h is extensive d iscussion of ap propriate controls to u se

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in classical con d itioning experiments, what were once seen to be unitary URs and CRs may actually have several componen ts which m ay be affected d i fferen­ tially by the Pavlovian paradigm . We have now come to the close of this presen tation of American con tribu­ tions to the discovery of n ew p henomena and rein terpretations of Pavlovi an theory . If nothing else , we hope to have s hown tha t the end result of the research p rocess on what was once considered a simple form of learn ing (classical con di­ tioning) has been to discover how complicated this learn ing may actually be. Our conclusion , therefore, is that we are still wa iting for a theory about the mechanisms underlying classical con dition in g which is adeq uate to predict pre­ cisely what sort of con d ition ing will occur in the various situa tions in which the Pavlovian parad igm may be applied . This l ack of an adeq uate theory to explain the principles govern ing classical cond ition ing has not, however, preven ted sign ificant a dvances in developing appl ica tions b ased on the Pavlovi an paradigm . In some cases, as we shall see , these advances h a ve even been related to basic research .

Recen t In nova tions i11 the App lica tion of tlze Pavlovia n Pa radign1 to Clinical Psy ch ology Ap plications of Pavlovian learn ing theory date back to the pion eering work of Mary Cover J ones (1924) , but they were largel y eclipsed by Freud ian psychoan alysis and other " insight" approache s . This situation was reversed when Wolpe's techn ique of systematic desensitization (reviewed in C hap ter 6) began to be employed in the late 1 950s . Wolpe b ased h is treatment on the P avlovian principle of rec iprocal inhibition, or coun tercon d i tion ing of con ­ d itioned avo idance responses ( p hobias) . In his view, cogn itive p rocesses were en tirely second ary to subcortically (usu ally au tonomically) mediated con d ition ­ ing of the p hysical responses assoc i ated with anxiety . As we have seen i n the work reported from Razran to Selign1 a n , however, it h as become apparen t that most classical cond ition ing processes m ay be in fluenced by cogn i tive variables . As a result, some of the new techn iques m ake allowance for variables such as se mantic gen eralization and the pred ictive values of cues (in Lazaru s, 1 977) ; few behavior mod i fiers see the ir therapy as simply automatic ally cond ition ing vis­ ceral correlates of fears . J ust as radical behaviorists are an almost va n ished bree d , so are rad ical behavior rno d i fiers who believe that n1ost phobi as are acqu i red by d irect cond i ti on ing of the type experienced by the u n fortunate "little Albert" at the hands of Wa tson and Rayner . Rimm and colleagues ( 1 977) investigated the origins of fears in 45 p hobic fem ale college studen ts . S ixteen subj ects could indeed recall a fri ghtening direc t experience, fou r became p hobic after verbal i nstruction from sign i ficant others (such as p arents ) , and three be­ came fearful after seeing someone else experience a frighten i n g even t (vicarious experience) . Combining subj ec ts who first reported feeling fearfu l in situ a tions not related to their phobias (nine subj ec ts) with subj ects w i th no recall about the origins of their fears ( th i rteen subj ects) , it can be seen that only abou t a third of the subj ects had first become p hobic as a result of a d irect con dition ing experi­ ence . Seven thought they had become p hobic as a result of a cogn itive

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learn ing event ( the verbal and vicarious subj ects) , and about half could not relate their phobias to any specific learning event . It m ight be assumed that these latter subj ec ts had acqu ired their fears through more abstract m e d i a tional mechanis m s . As we saw in our review of the literatu re on the role of mediating variables, the m aj ori ty of stud ies su pport the view of the i mportance of som e typ e of mediating m echanism, b u t simple Pavlovian pairing of cues cannot be ruled out. This would s uggest tha t the most effective behavioral modifica tion procedures would take into account both contigu ity and mediational factors . O ne theorist who has done this is Peter Lang ( 1 969) , who sees p hobias as poten tially h aving three types o f components : ( 1) verbal or symbol ic acts, such as saying, "I feel afraid , " or an u nw illin gn ess to push a bu tton th a t triggers the appearance of a slide p icture of the feared obj ect, (2) instru m en tal response acts, such as approach ing a feared obj ect, and (3) a visceral or autonom ically medi­ ated componen t . He has d eveloped au tom a ted procedures w h ich act on one or more of these components (and wh ich greatly reduce the boredom experienced by therapis ts when slowly p resenting a l is t of fear c ues) . O ne a dvanced device* i nclud e d not only a button (symbol ic act) allowing the subj ect to control the rate of progress through a series of sl ides depicting obj ects at d i fferent levels of the syste ma tic d esensitization fear h iera rchy, but also a m echanis m includ ing elec­ trophysiological recording d evices to sense the onset of visceral or sympathetic n ervous system arousal . The outp u ts of these devices go to a computer, whic h resets the slide presentation of fearsome cues to a level t h a t the clien t can tolerate w h ile au to ma tically turning on a tape-recorded voice giving ins tructions to relax . The effectiveness o f this a u tom a ted sys tem is reported as somewh at h igher than that of flesh a n d blood therap is ts, whic h is assumed to result from the m ach ine's greater consistency. This work also s u pports the contention of Wolpe and o thers tha t their results represent true coun tercond itioning and not placebo or therapist e ffects. Schandler and G rings ( 1975) h ave exp erimented with u sing electromyq­ graph ic (EMG) biofeedback techn iq u es to increase the depth of relaxation . When compare d to the tra d itional pro gressive (Jacobson- type) relaxation procedures u sed in most systematic desensitization , the EMG biofeedback d i d p ro duce greater decreases i n heart rate and res piration rates, and these changes p ersisted longer than changes created by progressive relaxation . Progressive relaxation , however, was more effective i n red uc ing psychological tension (base d on verbal reports a n d responses to tes ts of anx iety) as well as fron talis (forehead) and forea rm m u scle tension( ! ) . One is reminded of the results of basic research re­ ported earlier wh ich seem to s how tha t s keletal m u scle responses are more l ikely to be affected by procedures w ith grea ter cogn i tive- and/or contingency-based m e d iators . Control subj ec ts told to "j ust relax" showed no changes in tension or physiological functioning . Even though Wolpe considers the m ec hanism o f countercond i tioning to underlie the success of systematic desensitization , is it not possible th a t a sim -

* W hich he call e d " D A D , " or Device for A u tomated Desen sitization .

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pier explanation m ight suffice ? Remember that Rescorla's dogs in the cond ition where the CS (CS - ) pre d �cted the nonoccurrence of the shock showe d red uce d avoid ance behavior? The process by which an organ ism learn s that a CS no longer signals the occurrence of an aversive US is a form of learn ing not to be afraid of a cue or, m ore technically, of classical extinction of the fear-elic iting properties of the C S . This suggests that if a phobic person could be kept in the presence of phobia-related cues with nothing b a d h ap pen ing to them , their fear CR would eventually extinguish without the necessity of relaxation procedure s . Such forced extinction p rocedures, based o n s tud ies b y Solomon and Wynn e (1954) of traumatic avoidance learn ing i n animals, h ave been described b y Stampfl and Lewis ( 1 967) a n d are offered as alternatives to systema tic desensiti­ zation . The obj ect of such procedures is to te ach p hobic p ersons that no con ­ tingency exists b e tween the phobic cues and aversive events .

Forced extinc tion pro cedures

Stampfl and Lewis (1967) labeled their tech­ niques implosive therapy. Most authors (Marx and Bunc h , 1977) also call this technique flooding. Rim m and Masters ( 1974) , however, d istingu ish these two labels as correspond ing to som ewh a t different approaches to forcing the extinc­ tion of the phobic C R . I n theory, and somewhat in actual procedure, i mplosive therapy i s si m ilar to flooding, or response-prevention techn iques . . . . There are several d i stinct d i fferences, however. I m plosive therapy is based upon clearly specified assump­ tions concerning the p sycho-dyn a m ics of the i n d ividual under trea tmen t . Ear­ l ier, we noted that childhood trau m a is proposed to be the sou rce of most avo id ance beh aviors . Typ ically, in implosive therapy, scenes of avo ided behavior and s t i m u li are presented i n a hierarchical fashion, beginning w i th the less anxiety- provok ing i tems . . . . Flood ing or res ponse- prevention techniq ues requ ire that i m ages rel ated to s pec i fic beh avioral problems must be presen ted for suffic iently long periods of time to a llow the d i ssipation of anxiety . [R i n1 m and Masters, 1 974 , p p . 334-335 ]

Floo ding a n d implos io n therapy are two similar forced extinction techniques for relief of phobias . Both involve imaginin g a graded series of fearful s i tua­ tion s un til the fear res pons e has exti nguished.

While the passage j ust quoted would seem to im ply that i m plosive therapy rests on a M iller and Dollard type of theoretical base (combining Freud with learn ing theory) and flo od ing rests on the explanations of anxie ty presen ted by M iller and Dollard, Mowrer, and Pavlov, what happens in both cases is forced exposure to aversive i mages . The goal is always to force the client to face fear- or anxiety-arousing cues un til these cues become ineffectual through extinction of their con d itioned re inforcer properties . In Pavlovian terms, what happens is that num erous (or lengthy) exposures to a C S for a fear C R wi thout con firm ation by the original US ( the traumatic event) will lead to extinction as a result of the irradiation of inh ibi tion b u ild ing up through nonconfirm ation . The original

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p ersistence o f the CS may be explained through either M iller's and Dollard's or M owrer's models of the two stages involved in fear-drive learning. Forcing the subj ec t to confront the CS p revents him or her from escaping or avoiding, thus causing h is or her exposure to extinction contingencies . There is the d an ger, of course , that the subj ects may be so terrified that they will break down com­ pletely (which Pavlov would explain as the p athological result of a clashing of the excitation generated by the CS with the second sign al system cues that the CS is h armless) , or they may thwart the therap is t and continue their avoidance or escape beh avior. Barrett (1969) found that implosive therapy, whic h interprets the fear o bj ect and exten ds the extinction process to "symbolic ally" related obj ects, was effec­ tive in rem oving symptoms in only 45 p ercent of the tim e requ ire d with syste m ­ a tic d esensitization . The implosive therapy subj ects, however, showed consid­ erably greater variability in results than the s ystematic desensitization subj ects . Tha t is, while many were improve d , som e others were m ade m uc h worse . This is, of course, understandable w hen you consider the amount of fear encountered in facing a dreaded situation (such as imagin ing having snakes crawl all over your b o dy) . In the flooding p rocedure , no surplus m eaning is a ttached to the ima ges o f feare d h a p penings . The s ubj ect i s simply exposed to those im ages or, i n som e cases, t o t he actual obj ects . The procedure is m u c h l ike G u thrie's forced expo ­ s ure procedure . An example m ight be visualizing yourself getting b a c k o n a m o torcycle after an accid en t . You m ight b egin with visualizing looking at the bike, then sitting on it, then driving slowly, and fin ally driving between lanes of stationary autom obiles on the freew ay during rush hour. Flooding has been found to be q u icker than systematic d esensitization b u t less effective (Rim m and M a s ters, 1 974) . There a re several conflicting stud ies on exactly how effective either of these m e thods is . Except for possible savings of time , both appear to o ffer greater dangers and , at best, e ffectiveness equal to systematic desensitization (where the gradual progression through the fear hierarchy combined with relaxation enables the subj ect to face the phobic cues w i th little anxiety) . W hile K rapfl ( in Rimm and Masters, 1 974) fou n d that m any subj ects were helped w hen hierarc h ies of fear cues began with the most fear­ som e and avoidance was prevente d , dropout rates (a form of unavoid able avoidance , from the therapist's p oint of view) were m u c h h ig her than w i th conventional systematic desensitization procedu res . A recent s tu dy has carefully investigated the relationship between client satisfaction and e ffectiveness in reducing psyc hological and physiological signs of phobic anxiety using b oth the floodin g p rocedure and sys tema tic desensitiza­ t ion (Rudestam and Bedrosian, 1 977) . Cl ients h aving specific p hobias* rather than general anxiety in social situations s howed much greater reductions in t he p hysiological signs of arousal to the fear CSs . The social p hobics s howed som e ­ what less G S R a n d heart rate signs o f arousal after treatment b y flooding than with trea tm ent by systematic desensitization . But although flooding was found * Such as fears o f s n akes, dark places, w a ter, an d so on .

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to be more effective i n reducing the au tono m ic ally media ted com ponent of the fears, significantly m ore subj ects reported them selves as i mproved after syste m ­ atic desensitization ; this w a s most true o f the specific phobic s . Not only d i d the self-reports o f the subj ects contrad ict the ch anges in the physiological signs of arousal m e asure d , but the ir therap ists also rate d them as m ore i mproved after syste m atic desensi tization . Clients treate d by both meth­ o ds, however, were rated on the average as successfully treated both by the m ­ selves and by the ir therap ists . These results show, if noth ing else, that Lang is probably correct in considering a phobic reacti on to be compose d of multiple elements . In a sense , this conclu sion agrees with that reached in the basic re­ search literature : What were formerly considered u n itary responses to CSs have been found to be composed of several responses, not all of which respond in the same manner to a given cond itioning proce dure . The discrepancy between cog­ nitive system s (beliefs about the effectiveness of treatm en t) and actual m easure d con dition ing o f physiologic al m echanisms d iscussed in the previ ous study h as direct relevance to the top ic we will now exa m i n e .

Aversion therapy

Even though most pati en ts who come to a therapist do so for the purpose of gaining relief fro m fears an d bad feelings, so m e clients m ay be treate d with the therapeutic goal of inducing fears and anxietie s . Th is is usually the case in wh ich the client wishes (or som e referrin g agency wishes) to stop som e speci fic behavior dee m e d m aladaptive . The cond i tioning of fear re­ sponses to the CSs associated with cigarettes, pretty l i ttle c h i l dren , * overeating, and alcohol ism is the goal of aversion therapy . A US (usu ally shock or a n au sea­ in ducing drug, for treatmen t of alcohol ism ) is p aired w i th the obj ect or situation to be avo i ded or a graph ic representation of the obj ec t or situ ation . Even tually, the situation acqu ires cond itioned aversive properties and becomes capable of eliciting the fear response . Unfortunately, unless a classically cond i tion ed re­ sponse is strongly con d itioned, it may extingu ish q u ickly . Thus, an i mportant problem faced by the aversion-cond i tioning therapist is the i mpermanence of many of the "bad habit phobi as" so p a i n fully condi tioned " into" h is clien ts . Why i s i t that "n atural phobias" ( w h ich R i m m and colleagues, 1 977, have shown to be d i rec tly , let alone tra u m a t ically, con d i tioned in only about a th ird of their subj ects) are so resistan t to extinction? It is at th is point that the auto­ matic S-R condi tion i ng approac h to pathological behavi or i s m ost clearly shown to be inadeq uate . As Rudes tan1 and Bedrosian ( 1 977) de term i ned, cogn itions (beliefs) and the results of measurable cond i tioning m ay not always be co m ­ pletely congruent. Following the trends o f the basic research l i terature revi ewe d earlier in this chapter, the answer n1 ay lie i n an analysis of the client's expectan­ cies about the contin genc ies in the envi ron n1en t . P hobic clien ts may escape fro m un pleasant tasks or g a i n syn1 pa thy and atten tion (secon dary gain) for the ir pathology . During the au thor's counseling prac ticum ; he had a client who was a social worker and hated her work . S he appeared at the agency where the au thor worked becau se of a phob i a o f s mall elevators (found in m any of the build ings

*

T h i s is d i rected towards sex offen d ers, n o t poten t ial paren ts.

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she was requ ire d to visit) and of d irty p eople who m ight g ive her d isea ses (like some of her clients) . S he reported no d irect experiences with aversive conse ­ q uences o f b e i n g in sm all elevators or o f catching strange d isease s . It i s n o t h ard to see , in a situation like this, how cognitive variables related to her d islike of some aspects of her j o b m ight mediate the resistance to extinction of such p hob i a s . O n t he other hand , the client referred for aversive therapy usually likes doing the thing he or s he is suppose d to learn to fear. The expectancies of p ositive contingencies rel ated to resum ing the 0 m aladaptive" behavior and CSs conditioned to t hose posi tive con tingencies m ay confl ict with fear elicitation , resulting i n what appears to be rapi d , P avlovian extinction . The s timuli faced by the subj ect when tem p ted to perform the "m alad ap tive" behavior i n the real world would be compound stimuli consisting of CSs h a ving positive associa­ tions with the " m aladaptive" behavior as well as CSs having negative associ a ­ tions acquired through the aversive con d i tioning procedure. I n these situ ations, t he strong CSs related to positive a ssociations m ay overshadow we aker fear­ related CSs in the compound , and the subj ect will behave as if the fear CR had been extingu ished . Such competing processes m ay be illustrated by the following exam ple . The au thor was once i nvolve d as an assis tan t in a dm in is terin g aversi on therapy to an alcoholic j uvenile delinquen t w i th a h is tory of e ight years of im prisonm ent . He was given unl im ited quanti ties of swee t red wine in a b aby bottle to w h ic h was added gradu ally i ncreasing amounts of vinegar . W hen he at last became ill, he was cleaned u p and urged to drink m ore until he strongly refu se d . Following this treatment, he remained dry for over three month s . At this time a visitor to the halfway hou se facility smuggled a bottle of beer i n to the presence of our subj ect. Althoug h reportedly reluctant, the subj ect did succumb , and from that point onward he began to drink an i ncreasing variety of alcoholic beverages, beginning with t hose least like swee t red win e . Six m on th s after treatment, he woul d drink anything except wine a n d two years after treatmen t he would drink anything except swee t red wine-the sm ell of whic h continued to make him nauseou s . In this case i t is possible that even though the odor and taste of beer may have resembled that o f swee t r.e d wine to some extent , m ost of the CSs associated with beer were positive ones, and only a few ( perhaps secon d signal system cues related to alcoholic beverages i n general) were associated w i th nause a . Therefore , the p ositive associations oversh adowed t he effects of t he negative CSs presen t in the total stimulus situation , and he showed be havior whic h was m isin terprete d as extinction of fear CRs to alc o hol . A m ore conventional treatment for alcohol ics is to give them t he drug apom orphine, whic h i nteracts with alcohol to create a severe n a u sea and stays in t he body for up to two weeks . A reformed alcoholic enrolled in a sem inar in alcohol ism with t he au thor told him that w hen h is alcoholic friends felt a s trong need to resume drinking, they \.Yould s top taking t he ir apomorphine and then wait t he week or two requ ire d for the drug to become ineffective . In the absence of the US (nausea) , extinction of any con d itioned nause a to the smell and taste o f alcohol was rapi d , wi th each succeeding drink red ucing their con d i tione d anx­ iety and aversion . Raymond (1964) d iscusses the inadeq u acy of apomorph i n e

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cond itioning as a sole means of treatm en t . He notes that the treatment is usually only effective once the pqtien t has accepted the fact that alcohol is a serio us problem in h is life and he has agreed to u n d ertake the treatmen t volu ntarily . I n this form o f treatment, patients receive several da ily pairings o f alcohol and nausea (which is ind uced by the influence of apomorp hine) . The treatment con ­ tinues for a week to ten d ays, within the confin es of a " therapeutic commun ity" in a treatment cen ter. They are allowed to drink only a little, since to beco m e drunk allevi ates the nausea a n d allows n o con d i tion in g t o occur. B efore leaving treatment, patients are repeatedly warned of the hazards of alcohol an d tol d they will now be able to live withou t it. After leavi ng treatmen t, if possible, p rovi­ sion s are made for fam ily an d/or employers to check on patients' continued consumption of the apomorp h i n e . It should be clear from this report that effects of the aversive cond itioning are supplemented by a wide range of cognitive mediators . The selection of appropriate CSs illustrates a m aj or problem in learning. For many years it was thought that all poten tial CSs were equal in conditionability (the principle of equipotentiality discussed earlier) and that the law s of learning a p plied equally to all situations . Pavlov (1960) considered each type of sensory experience to be processed by different cortical analyzers . This suggested that CSs which were similar to the USs would be m ore easily conditioned since s horter connections in the brain would be req u ired . L ublin (1968) and L ublin and Joslyn (1968) found that the types of C Ss requ ired to produce lasting aver­ sive cond itioning varied as a function of the spec ific USs involved . They re­ ported that u sing electric shock as the US was effective prim arily through attac h­ ing anxiety responses to formerly attractive visual stim uli . If anxiety is the goal in therapy , this m ay be the o ptimal therapeu tic s trategy . Feldman and MacCul­ loch ( 1968) fou n d that hardcore m ale hom osexuals becan1 e anxious in the pres­ ence of nude or sexy males after s hock therapy and reported the ir lives to be happier a s a result (through avoidance of harassment) . There are im portan t l im itations to this approach , however . If shock is strong enough to prod uce long-lasting anxiety, these anxiety effects 1n ay generalize widely . " We do not wis h our former smokers to have to give up the ir smoking friends along with their c igarettes" (Lubin, 1 968, p. 78) . I nstead of s hock, which conditions anxiety, Lublin advocates n1 ore explora tion of o ther types of aversive stimulation . He has reported success in usi ng the olfactory cue of stale cigarette smoke in a negative practice paradigm* to stop cigarette s m oking without elic it­ ing general izable anxiety . Another advantage o f the use o f a nonshock US is that such cues are more d ifficult for the s u bj ect to d iscrim inate from natu rally occurring cue s . Mowrer (1938) reported that shock-con d i tioned autono m ic responses in humans disap­ peared as soon as the electrodes were d isconnected . Stale cigarette sm oke is much more d ifficult to d iscrim inate from ord in ary cigarette smoke than s hock

*

I n t h e nega tive practice para d ig m , t h e s u b j ect i s forced to i n d u lge i n t h e form erly enjoyed

habit until i t becomes aversive . I n L u b l i n ' s exam p l e , su bj ects were req u i re d to smoke to the count of a m e tronome u n t i l their eyes and l u n gs fe l t a s i f they were b u rn i n g . A few hardcore s m o kers see m e d to thrive o n th is proc e d u re , b u t m os t lost t h e i r de sire to smoke .

Adv a n ces in Classical Conditioning

2 23

situations are from nonshock situations . The taste of adulterated sweet red wine is also not that differen t from the unadulterated version of the same product. Powell and Azrin (1968) reported that 1 7 out of 20 subj ects in an experimen t involvin g severe shock for smokin g quit bein g experimental subj ects rather than q uit sm okin g . Summarizing his assum ptions about effective USs, L ublin relates : A short while ago , p u rsu i n g m y i ntere s t i n aversive stimulation, I was a guest on the Joe Pyne TV sho w . Mr. Pyne asked this q ues tion : "If you wan ted some­ one to hate tomatoes, I suppose you'd sock h im i n the face with a tom ato a few times . " My answer was, " N o . Tha t would be a good way to teach a person to h ate m e . If I wan ted h i m to hate tom a toes, I ' d feed h i m pu trefied tom a toes every day for a wee k . " [ 1968 , p . 80 ]

Lublin ( personal comm unic ation) h as also suggested some ingen ious ways to implemen t h is suggestions about u sing CSs on the same stim ulus dimensions as h is USs. For example, he claimed that telling overweigh t people to use toilet p ap er in stead of n apkins at m eals was an effective behavior modification technique . Aversive U Ss such as shock and nausea-inducing substances are used in aversion therapy to condition phobias of stimuli related to maladaptive behav­ ior, such as overdrinking.

All the therapeutic a pplications of classical con dition in g m ak e a fun d am en ­ t a l assumption consistent with the views of Ivan Pavlov. This assumption i s that p a thological behavior is b ased on the same laws of learn ing as normal behavior and that p athological behavior, therefore , results from bad learning experienc e s . This view assumes that a reord ering of the environ m ent o r recon dition ing o f disordered beh avior i s n ecessary in therapy rather than an "understan ding" of Freudian dynamic processes . However, Pavlov ( 1960) also recognized in d ivi d­ ual differences, to the extent of describing ind ivi duals dominated by excitation and those domin ated by inhibition , which is a recogn ition not held by all beh avior modifiers . Consistent with recent recognition of the complexity of the classical condi­ tioning paradigm an d a greater a pp reciation of the role of cogn itive mediators in s uch learning, behavioral modification in the P avlovian tradition has also moved from i ts strict behaviorist ori gins . Mahoney ( 1 977) , com m enting on the growing momen tu m of this cogn itive learning trend in p sychotherapy, con­ cludes that while the P avlovian experim ental p aradigms are still u seful, the form erly simple theoretical b ases are now outmoded and such techniques should be u sed with cogn itive procedure s . A recent example o f such a trend is the d evelopm ent of covert or imaginal aversion therapy, in which the subj ect internally visu alizes being n au se ated or shocked (the U S s) after imagin ing the CSs to be avoided .

App lica tions i n S ex Therapy Although most of the techniques u sed in the new sex therapy h ave already b een presented in this chapter (such as d esensitization) , the effectiveness an d recency

22.J

i\ I odcn1 Co11 te11 ders

of the extension of Pavlovian princi ples to th is cli n ical area warran ts a brief survey of such procedures . In a d d i tion, many of the techn i q ues have been adapted for " i n vivo" home use by couples . "In vivo" means " in l ife, " or in t h is case, actually fac i ng anxiety - arousing si tu ations " in the flesh" rather than co­ vertly visuali z ing them in a therapist's office. Because of the very nature of sexual dysfunctions, actual practice of sexual acts w i th a partn er is often req u i re d . Even i n th is l iberal age, such practice i n the therap ist's office would raise serious q uestions of privacy, as well as eth ical-legal issues . Let u s now look a t spec i fic techni q ues used for speci fic sexual dysfunctions, as rep orted in Helen Singer Kaplan's book, The Nezv Sex Therapy (1974) .

Male Dysfu nctions Inzpo tence Impo tence is the con d i t i on of erectile dysfunction . 1 n a sense, all the c auses of i mpotence del i n eated above involve faulty learn in g . The patient ren d ered impoten t by Oedipal con fl icts learned to fear sexu al ex­ p ression as a child; the u n happy husband learns to c ircu mvent the anxiety engen dered by the des tructive i n teractions w ith h i s w ife by avo id ance of all sexuality. However, spec i fic sexual pho bias may also play a rol e in so me cases of impotence . For example, some i mpotent men are phobic of the w o n1an's gen i ­ tals . [ Kaplan , 1 974 , p . 261 ]

Kaplan suggests that the sexual reflexes are primarily con trolled by exc i t­ atory centers i n the s p inal cord . When cues related to sexu al function ing become asso c iated with uncond i t ional stimuli w h ich e l ic i t sym p athetic ( fl ight-fight sys­ tem) arousal, anxiety , and i n h i b i tion of parasym pathe t ic don1 inance (wh ich is essential for pen ile erection) , however, these sexual cues may becom e con ­ d it ioned i n h i b itory stimul i . Therefore , the primary therapy for many sexual dysfunctions is d isinhibiting the i nh i b i ted spi nal reflexes to let sexual behavior occur "naturally . " One approach is to i n h i b i t anxi e ty by a negative re i n force­ ment approach . K a plan reports a case i n wh ich a man had a pa tholog ical fear of female gen i tals, leading to complete impotence . Therapy consiste d of shocking the man for avo i dance and tern1 inating the shock for approach . Along w i th the obvious operant elemen ts of this tre atn1 ent, it was assumed that the associ a ti on of female gen i tals (the cond i tioned s t i � uli) w i th the US of s hock term ination would eventually elic i t a CR of relief and hap piness . Therapy was su ccessful . A less dramatic and more pre ferred approach i s to have the couple practice a series of "nondemand" pleasuring tasks at hon1 e . These are of the type first develo ped by M asters and Johnson . The tasks begin wi th gen tle nongen i tal caresses and are followed by genital caresses but wi th co i tus proh i b i te d . The man is instructed to proceed sexually at h is own pace and to back up to an earlier point in the progran1 if the i n teractions become too threaten i n g . He is told to pay atten t ion to h is own sensations ra ther than worryi ng about pleasing h is wife , to reduce the demand character is t ics of the s i tuation and h is fears about failure . Only after he obta ins a rel iable erection does the couple move to i n tercourse . Kaplan recon1mends th at t h is begin with the w ife above an d w i th the man concen tra ting on sexual fan tasies . Until the man has confi dence i n the staying power of h is erection, in tercourse does not con tinue to ej aculation .

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225

This l atter appro ach is, of course , a specialize d variation of systematic de­ sensitization , or rec iprocal i n h ib ition . Origin ally , cues associate d with coitus are cond itioned stimuli for anxiety an d inhibition of t he erectile reflex . As com p are d to the desensitization procedures use d in the treatmen t of p hobias, pleasurable stim uli related to sexual behavior are used as the countercond ition­ ing stim uli rather than the stim uli associated with muscle relaxation . By intro ­ ducing t actile stimula tion in ways that are less l ikely to trigger the anxiety response, these cues resume their norm al roles as u ncon d i tioned stimuli for t he erectile and pleasure URs . G ra dually, a non fe arful response to coit al activity is s haped by keeping t he i nteraction at the level where it is pleasurable and not stressfu l .

Pre111 a t u re eja c u la tion

In a sense , this problem is the opposite of impo­ tence . W hile the problem i n impotence is to d isinhibit the exc itatory erectile reflex, in prematu re ej aculation an o verexcite d reflex m u st be partially inhib­ ited . O ne basic techn ique (the "stop-go" proce dure) a ttem p ts to cond ition those cues form erly associated with the a pproach of org asm , to inhibition of ej acula­ tion and often p artial loss of penile erection . Th is is done by h aving the male with draw h is penis from the vagina of the fem ale as soon as he experiences tho se cues signaling the approach of an ej aculation . H e does no t reen ter u ntil both t he urge and h is u rgency are gone . Before treatment, t hese warn i n g cues were excitatory con d i tioned stimu l i associated with the uncond itioned stim uli of the "s tage of inevitable orgasm . " As such , they were assumed to trigger the ej aculatory reflex (whic h is then a con d i tioned reflex) prior to the time it would otherwise h ave occurre d . G ra d u ally, the time to ej aculation would get s horter and shorter u n til, in some extreme cases, it was reported to occur as soon as t he penis tou c hed the vagi n a . After treatment, the warn ing conditi0n ed stimuli have been recon d itioned to inhibition of t he ej aculatory reflex . Even though this i n h ibition extinguis hes rap idly , each " s top-go" exercise retards the course of ej aculation u p to several m in u tes; by occasional " booster" exercises of the pro­ cedure , the man may develop alm ost com plete control over the tim ing of h is ej aculation . A more dras tic treatment for prem a tu re ej aculation is t he Seman's tech ­ n iq u e , whic h depends upon the fem ale's squeezing t he penis of the m ale a s soon as h e reports a n u rge to ej aculate . Done with s u fficien t force , this squeezing no t only inhibi ts ej aculation and red uces the erection but also pairs the urge for rapi d ej aculation with a highly p ainful and aversive stimulus. As this aversive cond itioning m ay generalize to the partner, m any fem ales are reluctant to u se this appro ac h .

Fe1n a le Dysfu n c tions Frigidity (gen eral sex u a l dysfu n c tions )

Kaplan. assumes tha t a female's failure to experience arousal d uring intercourse is the result of the association of aversive experiences (which would be inhibitory unconditioned stim uli) w i th sexual stim uli . These then become recond itioned to act as cond itioned inhib itors of sexual reflexe s . As with im p otence, the p rimary treatment is a modification of system atic desensitization, c alled t he "sensate focus" or

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pleasuring approach . In th is version, the woman sets the pace; intercourse occurs only when the woman feels rel axed and arouse d a fter nonco ital stimulation . Ka plan also sta tes th at women who voluntarily hold back their orgasms may become frigid . In th is case, the cues of holding back act much l ike the cues of inhibition of ej aculation exper ienced by the male trying to recon d ition premature ej aculation . Eventually , the stimuli formerly a ssociated with the onset of female orgasm develop into con d i t ioned inh ibitors . If this allows the woman to control herself in an anxiety- provoking situation , a reinforcement element may be a d d ed to the development of classically con ditioned inh ibition . Ka plan (1974) sees many female sexual dysfu nctions as resulting from involuntary overcontrol of the orgastic reflex . She also assumes that the female orgasm is easily conditioned and easily inh ibited . Wha t once started as voluntary inhib ition rap i dly becomes involuntary .

Vagin ism us

"Vaginismus is a conditioned response which proba bly results from the association o f p a in or fear with attempts at or even fantasies of vaginal penetration . The original noxious stimulus may have been physical p a in or p sychological distress" (Ka plan , 1974, p . 414) . The actual response is a rapid constriction of the m uscles surrou n d in g the vagi n a so that i nterco urse becomes painful and d i fficult or even impossible . This constrict � on is a normal UR of the vaginal area to pain or acute anxiety . It is only when the cues associated with sexual activity become conditioned stimuli wh ich elicit th is response as a con ­ d itioned reflex that constriction is pathological . Treatm ent consists of insertion of a series of gra d uated rubber or glass catheters, with each left in place until it can be tolerated w ithout d iscomfort. The last ca theter is the size of an erect pen is and is o ften left i n place overnight to facilitate the d econdi tioning process . The husband may be asked to in sert the catheters so that h is value as a con d itioned cue for the vaginal spasm s will be reconditioned . It is essential to procee d slowly so that the ca theters do not become CSs for the va gin ismus response . To deal with phobic elemen ts o f the wom an's fear of in tercourse, she may also be asked to v isualize successive scenes of her husband's approach , in con­ j unction with the Jacobson exercises, as in conventional covert d esensitization . To m i n i m ize the reestabl ish men t of the phobic reactions, i n i tial intercourse consists of the husband's entering and ren1aining n1 otionl ess unless otherwise signaled by h is wife . In itial thrusting is slow and gentle, and th rusting to orgas m is usually deferred un til the wife is able to be relaxed and unafrai d . This is to preven t cues related to her husband and in tercourse from being pain ful and hence retriggeri ng the vagin ism us re flex (Kaplan, 1974) . G entle reassuring con­ versation n1ay help by adding second signal systen1 s timuli which are incompat­ ible with s tress and fear . In many ways, th is approach is sim ilar to that taken in d ealing with the fear and tension associated with ch ildb irth . Chapter Perspective

Several signi ficant innovations in techn iq ues h ave been d eveloped by workers with in the orthodox Pavlovian tra d ition . While more ba sic princ iples have been added, however, understand ing of the mecha n is ms beh in d existing princ iples

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227

has not s hown a corresponding advance except to show that what appeared to be a sim ple form of cond ition ing is actually very complex. Many basic concepts derived from the work of Pavlov and o ther inves­ tigators of stimulus-type con d itioning h ave been applied in a wide range of problems . These applications include most of the types of behavioral modifica ­ tion i n which a one-to-one relationship with the therap ist i s stressed . The users of these applications typically report that such learn ing-theory - d erived methods are sign i ficantly superior to more conventional approaches . Critics h ave pointed out, however, that the bridge between the rigor of the laboratory and real world application is often s ha ky . In m any cases, only a few of the concepts or laws of learning theories are applied , and these loosely . In a d dition , cri tics have been reluctant to accept glowin g reports of success from those ind ividu als having a vested i nterest i n said success . Although application of stimulus-typ e or classical con d i tioning learn i n g theory i s widespread, most applications i n clin ic al psyc hology h ave been within the tradition al framework o f therap is t and client. Large-scale ins titu tional set­ tings h a ve b een more likely to use the principles of reward-based con d ition in g, the operant model of con ditioning developed most fully by Skinner and h is followers . I n C hapter 1 0 we shall exam ine these applica tions . Key Terms autonomic nervous system autoshaping aversion therapy blocking phenomenon central nervous system conditioned emotional re­ sponse (CER)

electromyographic poten­ tial (E M G )

negative practice paradigm

exterocepti ve

overshadowing

flooding forced extinction imaginal aversion therapy

Pavlovian paradigm predictiveness hypothesis psychophysiology rule of force

implosive therapy

semantic conditioning

conditioned suppression

interoceptive conditioning

semantic transfer

contingency

l earned helplessness

sensory preconditioning

Annotated Bibliography An excellent review of e arlier post-Pavlovi an R ussian work can be fou n d in G . Razran , "The observable u nconscious and the inferable conscious in current Soviet psycho physiology : I n teroceptive conditioning, seman tic con d itioning, and the orientin g reflex" (Psychological Review, 1 96 1 , 54, 357-365) . More cur­ rent and m ore compre hensive glimpses of tren ds in Soviet psycholo gy m ay be fou n d in S . Cole and M . Cole, "Three giants of Sovi e t psychology, Conversa­ tions and sketches" (Psychology Today, M a rch 1971 , 4, 43-98) a nd L. Rahmani, Soviet p sychology: Philosophical, theoretical and experimen tal issues ( N ew York : Intern ation al Universities P ress, 1 973).

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Rescorla's views about classical con d i t ion in g are given in R . A . Rescorla and R . L . Solomon , "Two- process learning theory: Relationsh ips between Pavlovi an con d ition ing and instrumental con d i tioning" (Psychologica l Revierv, 1 967, 74, 151-182) and R . A . Rescorla an d A . R . Wagner , " A the ory of Pavlovian con d i ­ tioning: Variations in the effectiveness of reinforcemen t an d nonreinforcemen t , " in A . Black and W. F. Prokasy ( E ds . ) , Classical condition i n g II: C u rren t theory and resea rch (New York : Appleton-Century-Crofts, 1972 ) , 64-9 9 . Seligm an' s theory of learned helplessness and classical con d i tion ing mechan isms is well presen ted in M . E . P. Seli gm a n , Helplessness : On dep ression, development, a nd death (San Francisco , C a . : W. H . Freeman , 1 975) . An excellent secondary source covering recen t work and theory related to classical con d itioning is J. F. H all, Cla ssica l conditioning and instrumental lea rning, A contempora ry approa ch (New York : J . B . L i pp incott, 1976) . The li terature on applic a tions of classic al con d i tion ing to psychotherapy is too vast to do more than sugges t a few s am ple readings . A very good second ary source, wide in scope , is D . C . Rimm and J . C . Masters, Beh a v ior therapy: Tech ­ n i q ues and empi rical findings (New York : Academ ic Press, 1 974) . Readable and historically important is M . C . Jones, "The elim i n a tion of ch ildren's fears" Uou r­ nal of Experim enta l Psychology, 1 924, 7 , 382-390) . An amusin g article about tech­ nological innovations in behavi or therapy is P. J . Lang, "The on-line computer in behavior therapy research" (American Psychologist, 1 969, 24, 236-239) . An article on recen t cogn itive trends in behavi or therapy is A . A . Lazarus, "Has behavior therapy outlived i ts usefuln ess?" (A m erica n Psychologist, 1 977, 32, 550-553) , and behavioral tec hn iques in sex therapy are d iscussed in H. S. Kap­ lan , The n e w sex therapy: Active t re a t m ent of sex u al dysfu nction s (New York : Brunner/M aze!, 197 4) .

R e cent D evelop m ents i n the Study of R ei nf orcem ent- R elated L earni ng

As we saw i n the last chap ter, m any new princ iples h ave been a d de d to the body o f knowledge about cond itioning contributed by Pavlov, an d several n ew theories about the mechan ics of such learn ing h ave been s uggested . There has been a p arallel a dvance in our u n d erstanding of reinforcemen t and of the types of learning norm ally associated with reinforcem ent m echanisms . The effects of reinforcement, the province of operan t or instru m en tal learn ing theories, are the emphasis of this chapter. Altho ugh the emphasis in the Soviet Union has b een on research using the Pavlovian p aradigm or some refin emen t of it, learning psycholog ists in the Unite d S tates h ave excelled in developing principles b ased primarily on the reinforcem en t p aradigm , or from procedures combining i n ­ s trumen tal and classical cond ition ing procedu res ( as in the work of Rescorla) . Two of the traditions reviewed in the first h alf of th is text have made the greatest contributions to understand ing cond ition ing-type learn ing . These are the Hul­ lian a n d the Skinnerian traditions . Though , as we s hall see , those theorists represen ting or closely identified with Skinner's b asic mo del of behavior h ave been most concerne d with develo p ing applications of connec tionist principles, m uc h valuable work has been accomplished by the neo-Hullians in developing instrumental theories of learn ing. Following our sequence of d iscussing H u ll an d Spence b efore Skin n er, we will briefly review some important contributions in the Hull i an tra d i tion . Then we will review three types of trends with in the Skinnerian mode accom panied by key critical treatments of some of the p rima r­ ily Skin nerian , or operant, school's explanations of central points ab out reinforcemen t-based learn i n g . This, in turn , l eads into C hap ter 10, whic h re­ vi ews princ iples a n d examples of the widely used behavioral modification prac­ tices based upon the Skin n erian or n eo-Skinnerian view of learn ing and behavior . Let u s now turn to selected develo pments w i th in the n eo-Hullian or instru­ m en tal learning approach to learn i n g theory. As you will d iscover, these con ­ tin u e H u ll's in terest in m otiva tional variables (for H u ll , drive and incen tive motivation) and are m uch more likely to develop mo dels of in ternal processes than theories developed within the avowedly atheoretical Skinnerian mol d . In reading the m aterial presented in th is chapter, you should focus on maj or new concepts such as the frustration hypothesis, errorless learning, modeling, and the Prem ack principle, as well as a ttem pts to use new concepts in explain ing

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pheno m ena such as the partial reinforcement effect . You should also beco m e fam iliar with new knowledge about the effects of controll ing behavior through use of aversive consequences. Contributions to Reinforcement Theory in the N eo-Hullian Tradition We have already revi ewed the con tributions m ade by several of H u ll's stu den ts (Spence, M iller and Dollard, � owrer) . The Hull ian tra d i tion does not end there, however. M any workers, either i n fluenced by Hull or H ull's studen ts, h ave generated a d d i tional hypotheses on the natu re of the reinforcem ent process . Many o f these hypotheses are related to Sp ence's I :\ or fru stration- induced- by­ nonrein forcemen t variable, and it is to these we shall tu rn first.

Ho1v Expos u re to Ll11 re1ua rding Exp eriences Influences the Effects of Re1v a rd Frus tra tion as a so u rce of n1o tiva tion One of the first of these m o d els of rnotivation was proposed by A m sel, a stu d en t u n d er Sp ence at the U niversity of Iowa . H e saw frustration as an acqu ired , aversive drive wh ich resembles pain exce p t that, unlike p ain, it is acqu ired as a res ult of the nonreinforcemen t of a form erly reward ed instru m ental response . When reward is delayed or not forthcom ing, the feeling of fru stration or the emotion o f anger resu lts . Am sel classified three typ es of cond ition ing events : reward , punis h m ent, and fru stration . Frustra tion arises from the absence of reward when reward is expecte d . This primary frustra tion becom es con ditioned to cues occurring before its elicitation (through classical condi tion ing processes) ; these conditioned cues beco m e aversive and gain drive properties . The an tic ipa tory fru stration responses to these cues becom e linked wi th cues as a fractional anticipatory frustration (r F-S F) m echan isn1 (like Hull's fractional an tic ipatory goal responses) , wh ich mediates behavior rela ted to expected frustra tion . This motivates the organ ism to show avoi dance of situations in which nonreward m ight be expected (Amsel, 1 958) . Amsel noted tha t the vigor of frustration - driven responses w as proportional to the d egree of anticipation of reward, w i th h igh degrees of a n ticipation producin g hi gh a mounts of frustration , high drive, and vigorous behavior. Wa gner exten ded this n1 odel to sugges t that the effects of frustration in­ duced by nonreward and those e ffects in duced by nontraun1a tic p u n is h m en t rn ay b e sim ilar. Much punishment is followed b y a res u n1 ption of the pu n ished response (which is maintai ned by sorn e sort of reward) , so that the p u n is h m ent i tself may beco m e a cue tha t reward is forthcon1 ing. I f the organis m then delib­ era tely seeks the punishrn ent (wh ich has becon1 e a condi tioned reinforcer) , one would be j us tified in speaking of cond i tioned masoch ism . J ust as the response decren1 ents prod uced by son1 e pun is h m ent situations are uns table and imper­ n1 anent , so are the response d ecrem ents produced by frustra tion that is subse­ q u ently followed by reward . For example, the stu dent who, by a m ighty effort, gets a good grade in wh at initially seemed an impossibly d ifficult course may s u bse q u ently enroll in even m ore difficult courses . Wagner ( 1966) notes that

R einforcem en t- Related Lea rning

23 1

depressant drugs which reduce the d istressing emotional effects associated w ith frustration or p u n ishmen t. u sually induce a n i ncrease i n the frustrated or p u n ­ ished response . By reducing the aversive e ffects of the frus tration o r p u n ish­ men t , the drugs permit the con d i ti oned re inforcement effects to act with full force . I t m u s t b e noted tha t in these models o f the effects o f frustration , the analy­ sis of the learned drive properties of frustration is very similar to M ill er's and Dollard's analysis of how fear acquires the properties o f a l e arned drive . M os t of the frustration drive models, however, suggest a contiguity mech a n is m (classical con d i tioning) , wh ile M iller a n d Dollard invoked a drive-reducti on mech a n ism . Amsel and others have postu lated that the frustration which is created by lack of an expected reward may become a conditioned motivator as the resu lt of drive redu ction on su bsequ ent trials or may lead to conditioned avoidance if su bsequ ent trials are not rewarded. Conditioned frustration can have both sti mulus and drive properties.

The p a rtial reinforce1n en t effect

Amsel h as used his frustration v ariable to explain the partial reinforcement effect (PRE) , in which occasionally rewarded resp onses become m ore resis tant to extinction . Amsel prop osed tha t the frac­ tional anticipatory frustration experienced in t he presence of the nonrewarded trials is followed by rewarded trials . Eventu ally, the drive properties of the frustration b ecome conditioned to the eventual reward and add to the drive properties generated by reward . The organism learns to work in the presence of fru s tration -generated cues, and, when experiencin g these i n ternal s timuli dur­ ing extinction, reacts to them by continuing to respon d . Rats wi th a h istory of consistent rei nforcemen t never learn to respond when frustrated; hence, the r F generated b y nonreward competes during e xt inction with tendencies t o respond . Capaldi developed a n alterna tive t o the frustration theory explanation o f the partial reinforcement effect which he called the sequential hypothesis . First, he suggested tha t performance during extinction is a better measure of the PRE (and s trength of learning in general) than acqu isition measures . (It must be noted tha t using extinc tion as a measure of learn ing is contrary to the view that losses of performance during extinction reflect m o t ivational decrements rather than losses of associative strength as such . ) He then u sed this measure to com ­ p are p erformance following tra i n ing w i th differen t types of sequences of re­ warded and nonrewarded trials . He found tha t two m aj or types of seq uence variables influenced the magnitu de of the PRE measured during extinc tion . First, transi tions fro m nonrewarded to rewarded trials produced greater PRE than transitions from rewarded to nonrewarded tri als (Capaldi , 1971) . This was influenced by the n u mber of nonrewarded trials occu rring before e ach rewarded trial and by the regulari ty w i th wh ich a particular number of non­ rewarded trials preceded reward when the number of nonrewarded trials was varied in the course of a p articular experiment . Capaldi (1967) predicted tha t greater experience with a specific n u mber of nonrewarded trials before re-

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warded trials would lead to greater PRE . He s uggested the following explan a ­ tion of w hy greater PRE resulted from nonreward t o reward transition s . Assume that, following a nonrewarded trial, the animal remembers the experience of nonreward and that this produces an intern al s timulus s tate characteris tic of nonrewar d . When the following trial is rewarded, the s timulus characteris tics resulting from t he p revious experience of non reward become a ssociated wi th the stimulus characteristics produced by the rew ard (such as reduction i n h unger drive) . Therefore , the stimulus characteristics of nonreward become conditioned to the instrumental response and acqu ire con trol over it. When the tran sition is from reward to nonreward , there is no associa tion of cues related to nonreward with drive reduction because the nonrewarded trial is no t followe d by drive reduction . Therefore, the experience of nonreward does no t acqu ire secondary drive or secondary reinforcer propertie s . This is why the specific sequence of nonrewarded to rewarded trials, not the total percen tage of rei n ­ forced trials, i s respon sible for t he PRE (Capal d i , 1971) . Capaldi (1958) has also conducted research on the effects of the predictability of reward fro m particular experiences with nonrewarded trials . He compared regular alterna tions of reinforced and nonreinforced trials to irregular alterna­ tions of such trials and found resistance to extinction was greater wi th irregular alternation s . This could be explain ed as due to the circum stance tha t the rats exposed to irregular al ternations h a d learned tha t any 'nonrewarded trial m ight be followed by a rewarded trial . C a pald i's theory assumes tha t the rat has the memory capacity to remember seq uences of reward and nonreward . He suggested tha t the form ation of such memories (or in tern al s ti m ulus states) begin s on the first trial and could be mod ified by a sin gle trial . That is, the rat can modify i ts behavior on the basis of what happened to it (reward or nonreward) on the trial j ust previ o u s . This prediction of the rap i d acqu isi tion of the factors leading to the PRE is o pposed to Amsel's pred iction tha t frustration responses are acqu ired grad ually over many trials and that frustration gradually acqu ires secondary drive properties through i ts associa tion with subsequent reward and drive reduction . Amsel, Hug, and Surridge (1968) tried to explain away the results of studies which had supported C a paldi's notion that PRE can be acqu ired in a small n u n1 ber of trials . Noting that these studies had used m ultiple food pellets, they s uggested that what appeared to be only one trial was, in reali ty , a situ ation in whic h the ra t made multiple approaches to the food cup. Hence , there were really many trials for t he frustra tion effects to develo p . Going fu rther, An1 sel (1967) sugges ted that per­ h a ps there were really two types of PRE : One wo uld develo p with massed trials and would be dependen t upon s timulus aftereffects (since massed trials are closer in time to each other, the men1 ory capaci ties tha t Capaldi's theory re­ q u ires would be more plausible) . The other would be a PRE that develop s with longer in tervals be tween trials and re flects conditioned frustration variables . Capaldi and Wargo ( 1 963) , however, have demonstrated tha t even wi th 20minute in tervals between res ponses, rats exposed to series of single al terna tions of non rewarded trials w i th rewarded trials showed grea ter resistance to extinc­ tion than rats given rewarded and nonrewarded trials in a random order with

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fewer nonrewarded to rewarded transitions . This suggests that the s hort- term memory capacity of the rat for seq uences m u st be at least 20 m in u te s . Thus, Capaldi's theory is a cogn itive theory to the extent tha t the rat's memory o f sequences and expectancies about sequences d e termine subsequent behavior. A stu den t w hose q uestions in class are only acknowledged part of the time may become more persistan t as a result, which may reflect a PRE e ffect. Capaldi referred to this effect as intertrial reinforcement and suggested that performance on each trial was regulated extensively by re inforcement associate d with e arlier trials . An example might be someone who goes to discos and receives several rej ections before being rewarded with a desirable d ance partner. With time , longer and longer intervals of rej ections will h ave less and less effect, o r the person will become increasin gly persis ten t (and accept some ratio of bad experi­ ences to good experiences as the normal price to be paid for the goo d experiences) . The P R E (partial reinforcement effect) , which is the increased resistance to extinction resu lting from intermittent reinforcement, created problems for early learning theori es, which said response strength was a direct fu nction of the nu mber of rei nforced trials. P R E has been explained by both frustration (Amsel) and sequ ence (Capaldi) variables.

The p artial reinforcement effect depends on chan ges from a rewarded to a nonrewarded s tate over sequences of rewarded and nonrewarded trials . If the total elimination of reward som e times has such a powerful e ffect on behavior, what would be the effect of increasing or decreasing the amoun t of reward after a series of trials? The answer is that increasing the amou n t of reward (or its desirability) sometimes inc reases the in tensity or rate of respon ding, and de­ creasing the a mo u n t of reward (or i ts desirability) u su ally decreases the inten ­ sity and/or rate of resp on d in g . These chan ges in respon d i n g resulting fro m changes in reward situation s are called contras t effects, a n d the organism's ex­ pectancies about reward in p articular situ a tions is calle d incentive motivation . Let us now examine research and theory relate d to these topic s .

Hozv Ch a nging the A 1n o u n t or Kind of Reward Influences B eh a vior Rezv a rd con tras t effects Another effect which is nicely explained by the frustration hypothesis is the type of contrast effect c alled negative contrast, w hich takes place w hen either the amoun t or the desirability of a reward is reduce d . Amsel ( 1958) suggested that a red uction in reward elicits a primary frus tration re sponse whic h in terferes with the organ ism ' s previous learnin g . H all ( 1976) h as p ro vided a n extensive summ ary o f stu dies o n the e ffects o f e ither reductions of reward or increases in reward . In most cases, a red uction in reward is followed by decre ases in response rates or in tensity of the responses . I n the first s tu dy of this type, Crespi ( 1 942) fou n d that re d uctions in amount of reward obtained by rats run n i n g down a runway resul ted in a red uction in running spee d . C respi also fou n d a p ositive contrast effect, in whic h increases

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i n the available amount of reward increased run n ing spee d . H all (1976) notes that this l atter effect has only been found by about h alf of the investigators testing for it; if one assumes that such an effect ex is ts, its mechanism must be other than frustration . A plausible explanatory m echan is m is that of the incen tive motivation variable (K) developed by Hull (1952) and further specified by Logan ( 1970) , w hose work will be revi ewed i m m ed i ately following this d iscussion of con trast effects . It has been the author's experience, for example, that the e ffects of a raise in pay on work perform ance in m ost j ob situations is, at most, a transitory increase in the amount of work perform ed . C onversely, t he effects of a reduction in pay or even receiving a sm aller raise than was expected u sually result in considerable emotional effects and reduced work outp u t . It m ay be suggeste d that posi tive contrast effects are usually weaker and m ore transitory than negative contras t effects . A student m ight i ncrease his or her rate of question asking in class if tol d by another member of the class that the q uestions were a valuable contribu tion ; this is an example of a posi tive contrast effect. Negative contrast i s the effect observed when amount o r desirability of reward is reduced. The effect is one of decreas ed response intensity or response rates . Some researchers have also found weaker positive contrast effects ' where increases i n amount or desi rability of reward leads to increases in response intensity o r res ponse rates.

A general m odel which could account for con tras t effects might pos tulate that the organism's expectancies about the amoun t an d desirability of reward influence the organism's incentive motiva tion . You may re­ call that one of the variables added by Hull in the 1 952 version of h is theory was K, or incentive motivation. L ogan h as refin ed this concept and defin ed it in a Tolman ian way: " Incen tive motivation, the i n d ivi d ual's expectation of reward for a given behavi oral response, is to be d is tinguis hed from the goal per se . It is a pull or motivation toward a goal . The goal is re inforcing, but the principle of re inforcement is a perform ance principle, not a learn ing principle" (Logan , 1 970, p . 1 92) . This focus on expec tancies is sim ilar to that of Tol man, who demonstrated through latent learn ing s tu d ies that learn ing could occur without food reward but faster ru nning time to the goal box appeared only after the rats had come to expect food to be there . Li ke Tolman, Sp ence, and some other theorists, Logan accepted a d is tinction between learn ing and performanc e . For example, a student may learn from classroom lectu res but m ay never d iscuss what was learned with professor or peers . Once the incentive is made available (such as course credit to be e arned by passing a tes t), however, the p revious learn i ng may be translated into perform ance. Logan also s aw incentive motivation as determ i n ing how responses were to be made. If a teacher reinforces verbose answers to essay test questions, stu ­ dents will couch their answers in flowery l angu age with long discourses on the material covere p . If the teacher m akes clear tha t b revity is preferred , the same

Incen tiv e nz o tiva tion a n d q u a n tita tive aspects of resp onding

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information may be written in a terse and telegraph ic format. Logan refers to such situations, in whic h. the reward is at least p artially d epen dent upon the n a tu re of the r€s ponse , as involving correlated reinforcemen t . Logan (1970) ex­ plained the decision p rocess in conflict situations as a function of the net incen­ tive motivation which results from s ubtractin g expec tancies about aversive events from expectancies about rewarding events . This m ay be seen in a study by R achl in ( 1972) in wh ich pigeons an d rats were trained to k ey- p eck or bar­ p ress, resp ec tively, for foo d reinforcement. This foo d reinforcemen t con tingency remaine d in effect throughout the experiment. A shock mechan ism was then activated so that every response would increase the level of s hock delivered to the subj ec ts (levels of shock declined bet\veen response s) . All subj ects con ­ tinu e d to respond a t a level lower than preshock b u t j u s t sufficien t t o main tain a constant shock inten sity . Logan would explain this "critical rate" o f respond in g as reflecting the net incentive m otivation resulting from subtracting the effects of shock from the effects of obtain in g foo d . This type of analysis could also be exten ded to expla in conflict behavior of the approac h - avoidance type described by Miller and Dollard, withou t evokin g the theoretic al constructs of goal gra­ dients . Logan saw incentive as d istin gu ished from reward in three ways : (1) incentive is learn e d , ( 2) incentive is not directly proportional to differences in the amount of reward available, and (3) incentive reflects the organ ism's expectan­ cies of reward rather than the actual con tin gencies . Logan saw the q uan titative aspects of respon d in g as determ ined by net incen tive motivation . Workin g too h ard increases the n e gative incen tive m otiva­ tion occasion e d by the punis hin g pain of fatigu e . Workin g too slowly decreases the expectancy of the amount of reward to be obtain e d . Therefore, the precise type of response made or the effort expended is usually carefully tailored by the respon d in g organism to yield the maximal n e t expected reward or incentive motiva tion . Logan's model can h a n dle the data on the relationship of reward amoun t to effort expen ded . We h ave already noted that som e researchers have fou n d increases in res pon se effort accompanying incre ases in reward durin g the course of an experimen t . The incen tive m otivation concept would also seem to apply to the data on the effort expen d e d by d ifferent groups of subj ects ex­ periencin g d iffering amoun ts of rewar d . H all ( 1976) has summarized 29 such studies; in all b u t six, effort was in dee d higher for subj ects in the groups receiv­ ing the h igher amounts of reward (or more d esirable rewards) . Most of the studies d i d not fin d the aspect of reward m an ipulated (taste, number of p ieces of foo d , amount by weight o f reward) to be directly proportional to the increases observ e d with " more" reward . This supports Logan ' s postulate that incentive is not d irectly proportional to the amount of reward a va ilabl e . There m ay also be time-base d factors, as when the h igh levels of reward obtain ed under large­ reward- per-trial con d itions lead to faster satiation (which red u ces the incen tive value of the reward) . Like many of the neo-H u llians reviewe d in this text, Logan has provided u s with a theory about som e detailed aspects of instrumental respond in g, whic h , b y includin g some cogn itive variables, fits n icely with m any of our in tu i tion s about motivation an d b eh avior. H is an alysis o f response discrimin ation , which

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views quantitatively d i fferent behavi ors as d i fferent res ponses, is congruen t with many a stu d en t's exp erience of carefully gauging h is or her amount of study effort to tha t required for an acceptable grade in each course . If you recall from Chap ter 4, Skinner ( an d the n eo-Skin n erians) foun d schedule variables to be better pred ictors of respon se rates, resis tanc e to extinc tion, and sati ation than the variables related to exp ectancies abou t typ e and amount of reward studied by the neo-Hull i an s . While m any o f the n eo - Hullian concepts h ave been useful in explaining a variety of behavioral p henomena in h u m ans and infrahuman organisms, the Skinnerian approach, with i ts greater emp h asis on m e asurable environm en tal determ iners of behavior (such as schedules of reinforcemen t rather than expec ­ tancies or such mediating variables as incentive motivation) , h as generated more real world applications . We will now turn to an examin ation of develop­ ments in neo-Skinnerian theory and research . Contributions to Reinforcement Theory in the N eo-Skinnerian Trad ition

Skin n er m ay well be the best known of living American psychologists, a n d researchers iden tified with h is operant con d i tioning approach to learning m ay be the most influential an d productive of any current school of learn ing theory . Among operant learn ing psychologists, at leas t three distinct trends can be identified : (1) extensions of Skinn er's approach retaining Skinner's emphasis on positive reinforcement, (2) extensions examining the effec ts of aversive conse­ quences (or the annoyers of Thorn d ike's first law of effec t) , and (3) m odels incorporating cogn i tive variables . Al though the assu mptions abou t learning held by workers operating within each of these three tradi tions are not entirely the same, all these offs hoots of the operant learn ing model have generated appli­ cations identified as part of the behavi oral modifica tion m ovemen t . The behav­ ioral modifica tion m ovement's operan t learn ing branch and i ts ties to o pera n t learn ing theory will be d iscussed in C h apter 1 0 . Among the extensions of opera n t theory emphasizing the role of positive reinforcement, we will focus on the work on d iscrimination learn ing by Skin­ ner's stu d ents, Reynolds and Terrace, and on contributions to new theories of re inforcement by Premack and by Ti n1berlake and Allison . These researchers have developed new principles within the o peran t n1odel and have s ugges ted some modifica tions of Skinner's emp irical laws and hypotheses about the nature of reinforcemen t . The second group of theoris ts have been active in developing empirical laws p ertaining to the effects of aversive contingencies; so me of them h ave suggested gu idelines for the development of applications using such contingen­ cies . In doing this, they have devia ted from Skinner's views . Skinner accepted Thorn d ike's later ( truncated) law of effec t, wh ich stated that the effects of pun­ ishmen t were both weaker and more unpredictable than the effects of posi tive re inforcement . Reading Skinner's wri tings on the subj ec t of aversive conse­ quences, the author p erceives that h is conclusions are b ase d on som ething less than extensive investigations of punishment. Skinner's argu m en ts against the

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use o f pun ishmen t d ep end heavily on pure theory and have a moralistic flavor . H e spent far less time investiga ting the effects o f aversive techni q u es than in conductin g research on the effects of positive reinforcemen t . C hapter 1 2 of Sc i­ ence and Human Behavior ( 1953) is titled : " Punishmen t: A Q uestionable Tech­ n iq u e . " This chapter begin s : The c o m m onest techn ique of control i n modern l i fe i s pun ishmen t . The pattern is fam il ia r : if a man does not behave as you wish, knock h i m down ; if a child m isbehaves, spank h i m ; if the people of a cou n try m isbehave, bomb the m . Legal and pol ice systems are based upon such pun ishments as fines, flo gging, incarceration , and hard labor . Religious control is exerted through pen ances, threats of exc o m munication and consignment to hell- fire . . . . The fact that p u n ishment does not permanently red u ce a ten d ency to respond is in agreemen t w ith Freu d ' s d iscovery o f the survivi ng activi ty o f what h e called repressed wishes . [Skin ner, 1953 , p p . 182-184]

fur Skin n er to evoke the n a m e of Freud instead of the results of controlled experiments is, to say the least, surprisin g. This bias against research on the functions of aversive s timulation has been severely critic ized by Solomon ( 1964) , who blames Thornd ike, Skinner, and Freud for originating "unscientific legends" abou t presumed ina dequacies and undesirable e ffects of aversive control . Solomon , S idman ( 1960) , Azrin ( 1967) , and o thers have attempted to correct this state of affairs by con d ucting a series of carefu l investigations . The models of learn ing whic h have a ttemp ted to synthesize operan t and cogn i tive principles are best known through the work of Albert Bandura ( 1969) . Along with M ischel ( 1973) and other so-called "social learn ing" theorists, he has succeeded in provi d ing a vi able altern ative to rad ical (Skinnerian) behaviorism whic h conform s with the experimen tal orientation of the behavioristic view . Social learning theory has combined aspec ts of M iller's an d D ollard's emphasis on the importance of in d irect or im itative learn ing, Skinner's emphasis on rein­ forcement, and Tolman's use of subj ective expectancies as a basic u n i t of l earn ­ ing. As a form o f cogn itive behavi oris m , social learn ing theory has con tinued the Tolm anian-function alist tradition of combining laboratory researc h with " m en talist" variables . As with all behaviorisms, social learning theory, as i ts name implies, is focused on environm ental d eterm in ants of behavior .

Contrib u tions of Neo-Ski n n eria ns E 1nph asizing Positiv e Re inforce1n e n t S tim ulus control of a tten tion in discrimina tion learn ing

The first s tep in d iscri m i n ating one cue from another is to p ay a tten tion to the releva n t cue dimen sion . If the organ ism is to learn to tell red lights from green lights, i t m ust first focus on color and not on other stimulus d im ensions such as brightn ess or shape. Reynolds ( 1975) has introduced the term superordinate stimuli to d escribe the class of stimuli whic h serve to d irect the s ubj ect's a tten tion towards a particular property of a si tuation . As such, they act to focus p ercep tion . For example, when a stu d en t is told that research fin d in gs will be s tressed more than theories on a test, s he or he will focus on learn ing and discriminating salien t

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features of research fin d ings . Hence, superordinate stimuli are a spec ialized subclass of d iscriminati ve stimuli (S 0s) wh ich tell the organism that reward is more probable if it pays attention to particular aspects of a complex array o f stimuli. They also tell the organism when a particu lar c u e i s l ikely to b e important i n a particular con text (as when a specific sched ule of reinforcemen t is likely to be in effect) so tha t the organ ism can focus on relevant rather th an i rrelevant S 0s . These stimuli determ ine wh at is figu re as opposed to ground as well as what types of cues can elicit the OR (orienting reflex) . Pigeons can learn to respond to the shape of illuminated figures when a red cue ligh t is on and to the color o f the figures when a green cue ligh t is on . The cue lights function as superordinate stim u l i . This concept is usefu l in explaining why a particular stimulus may be a cue for action in one context, a cond itioned reinforcer in another, and ineffectual in a third . Cues which direct a t tention t o the salient stimulus fea tures of a discrimina­ t ion learning situation are superordinate stimuli. They tell the organism which other stimuli t o focus on.

L e a rn ing to discrinz ina te the condi tio ns of reinforcenz en t

We m en tioned in the previous d iscussion that superordinate stimuli ca,n tell the s ubj ect when a particular schedule of reinforcement is l ikely to be in effect . Let us now exam ine material on the learn ing of o ptimal response pa tterns for particular con d itions of reinforcemen t . We have already d iscussed the p ositive a n d n ega tive contrast effects created by changes in the amount o f reward available for ins trumental responses . There is a sim ilar p henom enon generated by sh ifts in the type of reinforcement use d , o r of the schedules of reinforcement used (including sh i fts t o extinction sched­ ules) , called b ehavioral contrast by o p eran t learn ing theorists . Reynolds made behavioral con trast a s tand ard term in the operant vocabu­ lary, although the p henomenon he d escribed was first d iscovered by Pavlov and later investigated by Skinner . Behavioral contras t may best be described as a change in response rates in a d irection opposite to that expected from the opera­ tion of gen eralization . Reynolds sta tes : We h ave an exam ple o f generalization w hen a c h ild's unruly behav i or ext i n ­ gu ishes m ore slowly t han usual a t h o m e because i t i s re inforce d o n t h e play­ gro u n d ; we have an example o f behavioral con trast w hen t he ex t i nc t i on of u n ruly behav i or at home makes for increasi ngly frequ ent u nruly behavior on the play­ groun d . Contras t see m s t o depend o n t he rela tion between the rei nforcing cond i ­ t ions asso ciated w i t h t h e two s t i muli . W hen t he conseq uences of a response beco m e less re i nforcing i n t he presence o f one s t i 1n ulus, we can expect t he frequ ency o f the response to increase i n t he presence of a no t her s t i m ulus where i ts conseq uences remain rei nforc ing. [ 1 975 , p . 50]

The concept has been extremely important in explaining some of the effects o f punish ment in the real worl d . The respond ing person learns to d iscri m in ate where and from whom p u n ishment is l ikely to originate. The result of this is that

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responses suppressed by the p u n ishing are acted ou t in a safe environm en t . The h igh rate of rec i d ivism among incarcerated felons may illustrate th is p rincipl e . The an tisocial responses th a t are suppressed b y punishmen t in the prison envi­ ronm en t are emitted ( an d often rein forced) once the former felon graduates to the streets again . The principle of behavioral contrast can also be used to explain the effects of con trasti n g two schedules of reinforcemen t . When an organism is o ffered the c hance to e arn reinforcem en ts on a schedule that is "richer" (more reinforcem en ts/response) than i ts training schedule, the rate of respon d in g to the new, rich schedule will be h igher than for subj ects begin n i n g with th at schedule . In add ition , the rate of resp on d i n g to the old, lean schedule will drop far below training levels . Th is only applies when the cond itions under wh ich each schedule is to be in e ffect are clearly m arked by S 0s . In gen eral, the term "contrast" is used whenever rates of respon d in g to two d ifferen t stimuli or con d itions move in o pposite d irections . When there is beh avioral con trast be­ tween the compon ents of complex or multiple schedules, the in teraction effect of the schedules results in d ivergence of response rates . Waite and Osborne (1972) were e arly demonstrators of th is e ffect. Un der controlled con d itions, they exposed ch ildren to two types of multi ple schedules. In the first case, the components of the multiple schedule were as follows : Variable i nterval schedules were presented successively . In these, the chan ge fro m the first independen t schedule to the second in d epen d en t schedule was marked by a d iscriminative stimulu s . Response rates to each schedule were eq ual , showing the absence of contrast effects . The second multiple schedule h ad a variable in terval schedule as its first component and an extinction sche d ­ u l e (signaled b y an S � , as before) as i ts secon d componen t . As the ch ildren were exposed to altern ating s uccessive presentat ions of these two com pon en ts, a re­ ciprocal p attern emerged : Response rates to the variable in terval component increased as resp onse rates to the extinction schedule d ecrease d . Th is d i­ vergence of response rates to the two components illustrates the phenomenon of su stained behavi oral con trast, an effect wh ich can be compared with the momen ta ry con trast e ffects obtained when a subj ect is sh ifted to an extinction schedule that is not part of a m ulti ple or complex schedule paradigm . These momen tary extinction e ffects usu ally consist of short-lived increases in the rate, vigor, an d variety of responses emi tted (Staddon and Simmelhag, 1971) . Behavioral con t rast occurs when t he orga n ism discrimin ates between rein ­ forcin g con ditions in two or more situation s (or two or more S ns ) . In con trast t o gen eralization , respon se rates t o t he stimuli sign aling reinforcemen t i n ­ crease as respon ses t o the cues sign aling n on reinforcemen t decrease ; in ot her words, response rates in t he two situa tion s " move away from each other. "

Learn ing discrin1ina tions zuith o u t errors

Although behavioral con trast il­ lustrates one way in wh ich organ is ms maximize positive effec ts fro m the en vi­ ronment and m i n i m ize aversive or unreward ing effects, our n ext topic is a

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procedure w hich elim inates unreinforced respondin g . This is the errorless learning or fading techn ique developed by Terrac e . Several early discrim ina tion learn in g s tu dies (reviewe d i n Hall, 1976) found that subj ec ts (which ranged from rats to monkeys to children) given exposure to incorrect cues and making incorrect responses (unrewarded responses) in the presence of those cues learned d iscrimin ations faster th an subj ects only exposed to the cues sign aling reward or given m in imal exp osure to the cues signaling nonreward (S - s) . These results suggested that presentation of the S- and respon d ing to it were importan t in learn in g simple d iscrim in ation s . Therefore, Terrace ' s demonstration that discriminations could be learned without any incorrec t responses at all has considerable theoretic al importance in understan d­ ing discrimination learning. Before Terrace's development of h is errorless learning tec h n iq u e , i t was widely believed that discrimin a tion learn ing depended u pon a process in which the organ ism made some errors and failed to obta in rein forcement following those errors . This was thought to weaken the tendency to make such responses; thus, by the process of elimin ation, the subj ect would be more l ikely to emit the correct response , wh ic h would then be followed by reinforcement. The rein ­ forcement would strengthen the tendency to repeat the correct response, an d , through a process o f classical con dition in g, cues assoc iated with the reinforcer's occurrence would become CSs or d iscrim in ative sti m uli (S 0s) . The c ues asso­ ciated with nonoccurrence of the reinforcer ( the US) would become CS - s or, in o perant terminology, S �s . Terrace (1963a) was able to s how that errors were not an essential elem en t in discrimination learn in g . Using pigeons as subj ects, he demonstrated such learn ing in the absence of nonreinforcemen t of the S - . He began by lighting up the S 0 pecking key, m aking it an in vi ting target for pigeon p ecking, * and no ted that his subj ects began imn1 ediately to emit these correct responses . Terrace then gradually incre ase d the intensity of the light behind the S - key (whic h had originally been com ple tely d ark) , un til it was as bright as the S n key. Still the pigeons con tinued to peck only a t the S 0 key ( the correct key) . Thus, a completed discri1n ination was achieved wi thout the element of error, whic h would have resulted in nonreinforced tri als . Terrace describes his proce­ d ure as follows: Responses t o S - ("errors" ) are no t a necessary con d i t ion for the forn1 a t ion o f an opera n t d iscri m i n a t ion of color. Errors do not occ u r if d iscri m in a tion tra i n i n g beg i n s early i n con d i t ion i n g a n d i f S + a n d S - d iffer w i th respect t o brigh tness, d u ra t i o n , and wavelen g th . A fter tra i n ing starts, S - ' s d u ra t io n a n d b r i gh tness is progress ively i ncreased u n t il S + and S - d iffer only w i th res pect to wavelen gth througho u t tra i n i n g . Perforn1ance fol low i n g d iscr i n1 i na t ion learn i n g w i tho u t errors l acks three c h a racterist ics tha t are fou n d foll o w i n g learn i n g w i th errors . O nly those b irds tha t learned the d iscr i m i n a t i on w i th errors s howed ( 1 ) " e m o t i on al" responses i n the presence o f S - , (2) a n i ncrease i n the ra te (or d ecrease i n the la tency) of the i r response to S + , a nd (3) occasional bursts of res pon ses to S - . I l 963 a , p . l ]

*

The tend ency of the p igeons to peck a t the l i g h t e d key w i t ho u t extensive shap i n g m a y be an

ex a m p l e of the a u to s h a p i n g pheno m enon d iscu ssed i n C h a p ter 8 .

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Terrace (1963b) extended this learn ing without errors over two d imensions in a proced ure whic h b egan with a d ark circle ( the S - ) and a bright red c ircle ( the S o) ; gra dually, a green ligh t was faded in for the S - (S 11 ) . After s timulus con trol had been s hifte d from brigh tness to color (wavelength ) , a geometric shape was a d ded to the brigh t red S 0. Another shape was then gradually faded into the S- and the colored lights were faded o u t . At the end , the s ubj ects were making perfect shape d iscrim in ations without e ver havi n g m a de errors ! Schus­ terman has replicated these res ults in the Cal i forn ia sea l ion (1966) . (In some respects, this procedure has much in common with sensory precon ditioning; color and brightness are originally p a ire d without special contingenc ies for re­ sponses to color, and color is then shown to have acqu ired the p roperty of being a S 0 thro ugh i ts association with brightness as a S 0. ) Skinner has developed a version of this procedure , labeled vanish ing, as an aid for teaching ch ildren to draw the letters of the alphabet. I n th is procedure, the c h ildren are given letters which they are to trace on sheets of paper . The paper u sed has been chem ically treated so th at errors show up as bright yellow . In add ition , the concentrat ion of the dye decreases from the top to the bottom o f the page , so t h a t a t the end the children are tracing the le tters without the extra feedback of the d ye . Another techn ique presents m aterial to be learned (usually i n a p rogrammed text) with som e of the letters of the answers to questions printed in the blanks where the answers are to be written . Such promp ts are gradually red uced or faded out as the program progresses (Skinner, 1 968) . I once con d ucted a research proj ect in w h ic h fad ing techn iques were used to teach elementary school c hildren to d iscrim in ate sym m e trical figures from nonsym­ metrical one s . Unfortun ately (from the perspective of developing useful educa­ tional techniques) , although significan t d ifferences were fou n d , they favored traditional d iscri m in a t ion tra ining over the fading p rocedures ( S1.venson , 1 969) . By design ing a procedure which eliminates the aversive effects of frustration related to making errors (wh ich are nonreinforced responses) , Terrace has m oved behavioral technology one s tep closer to Skinner's i deal of learning envi­ ronments devoid of aversive failure experiences . Terrace developed a method of errorless learnin g or fading which in volves s hifti n g s timulus con trol from a highly salien t cue which always s i gnals the availabili ty of reinforcemen t to a more di ffi cult s ti mulus dimen s i on . If thi s is don e gradually, the organism en ds up always respon di n g correctly on the more diffi cult problem without ever having made errors .

The effec ts of p rior discrilnin a tion learning on genera liza tion

H anson (1961) found tha t when pigeons were tra ine d to peck a key illum inated with a part icular wavelength of light ( the S n) and not to peck the key when it was illum inated by sim ilar h igher and lower wavelengths (S 11s) , a very steep gener­ alization grad ient was found . This generalization gradient was much steeper than that obtained from p igeons in the con trol group that were only exposed to the S 0 (reinforced cue) . If only a single S 11 was u sed in the d iscrim ination tra i n ­ ing, t h e p e a k of the generalization gradient was shifted away from the S 0. This peak shift phenome non was also found by Terrace (1963a), except when he u sed

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errorless learn ing procedures . Th is suggests that the organism does not develo p any tendencies to avoid the potential S � when it never exp eriences the presum ­ ably aversive event of respond ing to the S � an d no t receiving reinforcemen t for the respon se . In errorless learn ing, therefore, the organ ism only learn s to re­ spon d to the S 0 and does not learn what not to respon d to . G eneralization gradients after d iscrim ination train ing with one, two, and no ( errorless learning or con trol groups) S �s are shown in Figure 9 . 1 . Note that the peak of the one S � group is shifted towards the left away from the sin gle S � ' wh ile the generaliza­ tion gradient is flatter for the control or errorless learn ing gro u p . Pri or discri minati on traini ng in which the S0 is " su rrou nded" by S�s res u lts in a steeper generalization gradient. I f the pri or traini ng involves a si ngle s� on one si de of the S0, the peak of the generalization gradi ent will " shift" away from that s�.

Of the phenomena related to discrimination learn ing that we have covered in th is section of the chap ter, only the errorless learn ing techn ique has directly generate d real world applications, although all these phenomena may have im­ portant implications for ap plications . The work of Davi d Premack, the first learn ing researcher we will examine in the following section , has gen erate d m any useful applications . These applications, along with others derived from the operan t approach to learn ing, will be reviewed in Chapter 1 0 .

Reinforce n1 en t a s t h e opport u n ity to respond

David Premack h as con tri b­ uted two important hypotheses to the psychology of learn in g : the prepotent theory of reinforcement and the reversib ility (transitivity) of rein forcement. These concepts have been useful in formulatin g a d efin i tion of reinforcement that is not contradicted by experimental data and th a t also happens to be more specific than Skin ner's defin i tion . Breger an d McGaugh ( 1 965) , cri ticizing Skin­ ner for fa iling to provide a specific lis t of rein forcers, have s u gges ted that h is defin ition of re inforcem en t in tern1s of behavioral consequ ences is noth ing but a circular defin ition (tau tology) . While Skinner's view, that a reinforcer is any­ th ing w h ich can increase the probability of the reen1 ission of a response, is in the tradi tion of Thornd ike's sta ten1ent th at a satisfier is anything the organism see ks to prolong, such staten1ents only penn i t the identifica tion of a reinforcer after the behavi oral event. Pren1ack's hypo theses o ffer a way to predict effective re inforcers in a dvance, without aban doning the a theoretical- fu nctional ap­ proac h to specifying the emp irical law of e ffec t . Note that in Pre n1 ack's theory (and in the modifica tion of tha t theory proposed by Ti n1 berlake and Allison) , re inforcers are responses (or the opportu n i ty to en1 i t responses) ra ther than things, as in n1 ore conventional views . The pre potent theory of reinforcen1 ent allows Premack to pred ict wh ich events w ill serve as rein forcers rela tive to specified ins tru mental behavi ors . He states th is theory as follows : "Any response A will re inforce any other response B, if and only if the ind ependent ra te of A is greater than th a t of B" (1959, p . 220) . I n most cases, these ra tes are measured using a paired b aseline techniqu e .

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Wave l en g t h s of L i g h t U sed to I l l u m in a t e t h e Peck i ng K e y i n N a nometers

Fig u re 9 . 1 Idea lized gen era liza tion g ra dien ts for gro ups of pigeons tra i n ed to p e ck a t a S 0 illu mina ted by lig h t of 550 n a no m e ters a nd also giv e n experience wi th th e key lig h ted (or a n ­ o ther key ligh ted) ·with either t w o s u rro u n ding wa velengths ( two S � gro u p ), one other wa ve­ leng th sho w n as 540 n a no m e ters in this figu re (on e S � gro up ) , or no effective S � (errorless lea rn ing or con trol g ro u ps ) .

This technique consists of simply collecting baseline data o n the " free operan t" rates with whic h two behaviors are emitted . The behavior which has the h igher operan t level can be u sed as a con seq uence (reinforcer) if access to i t is m a de contingent u pon the organ ism perform ing the l ess likely (lower operan t level) response . Today this modern version of mother's m e thod of behavioral control ( " Ea t you r spinach and then you can have ice cream") is called the Premack principle. Premack also a dvanced the hypothesis of reversibility ( tran sitivity) o f rein­ forcemen t . This hypothesis s ta tes that reinforcers are relational or relative to the rates with whic h they are emitted d urin g baseline con d itions, compared to specific altern ate behaviors . Thus, a given response may on one occasion be more probable than another response and serve as a reinforcer for the second response . If con d i tions were to be chan ged to make the second respon se more probable than the first response, then it would be the second response which would be the rein forcer. This reversibility o f reinforcemen t hypothesis gives rise to so m e surprising prediction s . If Prem ack is correct, then l icking water from a drinking tube (at least for a rat) is rein forcing b ecause l ickin g is a h igh proba bil­ i ty response rel ative to other behavi ors, such as bar-pressin g . G i ven that tissu e d eprivation associated with thirst i s n o t reduced immediately a fter drinking, and given that most organisms will emit instrum en tal responses to gain access to nonnutritive but tasty liqu ids, such a resp onse- probability theory of rein­ forcemen t may be more effective in p redicting behavior than e i ther Skinnerian d efin i tion s o f what a reinforcer is or drive - reduction defin itions . For example, P remack's hypotheses predict (as would most defin itions of reinforcemen t) that

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water deprivation could cause a rat to learn to run on an exercise wheel for purposes of ga in ing access to water . Premack, however, would also predict th at by restricting access to the exercise wheel and allowin g free access to drinking, a situation could be created in which "wheel - running" becomes the h igher­ p robability response during paired-baseline m easurement; hence, it s hould be an effective reinforcer for increased drinking ( 1 962) . Premack was able to de m ­ onstra te that rats deprived o f opportu n i ties t o o perate the exercise wheel would drink water to gain access to wheel-running even when they h a d consumed a normal day's ration of water. These results support both the prepotency hypoth­ esis (wheel-running becam e the more p otent or probable response when its occurrence was reduced below baseline m easure levels by the wheel-running deprivation procedure) and the reversibility h yp o thesis (in most situations, drink ing would have been the rein forcer and wheel-run n in g the ins trumental response) . The Premack principle h as importan t implications for the design of contingency management system s; in these, behaviors m ay be used as reinfor­ cers ra ther than physical rewards (such as food or toys) . Examples of con­ tingency management-based behavior modificat ion programs wh ich utilize the Premack principle will now be p resented . Homme and col leagues (1963) u sed th is principle in controlling " acting out" (screaming, running around the room) behavi ors in three three-year-old sub­ j ects. After baseline measures had been made of " act'ing out" beh aviors (h igh probability) and of sitting q uietly in a chair an d lookin g at the blackboard (low probability) , the researchers began the procedure of waiting for the few in­ stances in wh ich the low- probability beh avi or was being e n1 i tted . They would then ring a bell and give the instruction : "R un and scream . " The subj ects would leap to the ir feet and run around the room screa m ing un til the sign al to stop was given . Wi thin a few d ays, ra tes of " acting out" were grea tly reduced and "sit­ ting q u ie tly an d watchin g the bl ackboard" greatly increase d . The authors note that they had achieved good behavioral con trol without the necessity of using any aversive consequences . At a later stage , the children were able to earn tokens for em itting low- pro bability beha viors; these tokens could be exchange d for the opportun ity to engage in h igh- proba bility activi ties . Todd (1 972) used a covert type of Pren1 ack pri nc iple to pron1ote the devel­ opmen t of self-es teen1 in a depressed won1an . The won1 an was instructe d to write down all the posit ive th ings about herself th at she could think of (a very low- probability behavior) ; with con siderable pron1 pting from the therapist, she was a ble to fin d six such s ta ten1ents . These w ere printed on a card that was tri n1 n1 ed to fit inside the cellophane wrapper of a cigare tte package . Since smok­ ing was a h igh-probability behavior for her, she was instructed to read one or two of the items and to th ink posit ive thoughts about herself before tak ing a cigare tte fron1 a pac k . Within two weeks she reported feeling be tter than she had in years, and she had added 21 p ositive items to her lis t . You can also use the Premack principle to d irect n1ore of your time towards s tu dyin g . If yo ur first act in the morn ing is to brush your tee th or make a cup of coffee , try making the perforn1ance of these higher-p robability behav iors contingent upon the comple ­ tion of a few· pages of study material (a low-probability b e havior a t that t i m e o f d a y for most o f us) . Premack's hypothesis (that the differen tial probabilities o f

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245

responses determ ine what will be effective as a reinforcer) brings us a long way from conceptualizations of re inforcement, ei ther as " s atisfiers" or " annoyers" or a s the result of d rive- reduction mechanisms . It also represents a n advance over the d e finitions of reinforcement p resented by Skinn er and Spence . These theorists i gnore speculations about p rediction i n favor of a m ore p rag­ m atic defin ition of " re inforcers" that is couche d in post hoc terms (that is, some responses are emitted at higher rates following specific e nvironmental events) . These empirical law of effect d efin itions not only fail to predict i n a dvance whic h events w ill i ncrease or decrease instrumental behaviors, they are also u n able to handle the reversibility-of-reinforcement effects found by Premack . Premack's princ iple p redic ts the outcome of contingencies between two events previo usly defin ed as reinforcers and also predicts the failure of a satiated rat to continue working for a food "re in forcement. " Timberlake and Allison ( 1974) note that reinforcement is usually seen as s trengthening tendencies to respond (or as driving a learn i n g process), an d that b oth this strengthening o f learn ing view of reinforcement and the empirical law of effect are derived from Thornd ike's original law of e ffect . These authors point out, however, that the strengthen in g process is intuitive : "The process itself is a mystery" ( 1974, p . 1 49 ) . As we saw in our discussion of research by Rescorla and others on classical cond itioning, the processes of that apparently simple learn ing are still unknown, are debatable, and m ay be multipl e . Timberlake and Allison ( 1974) note that p henomena such as all-or-none learning, latent learning, and p artial-reinforcem en t effects suggest the i nvolvemen t of similar multiple pro­ cesses in what h as usually been seen as the unitary p henomenon of instrumental (or operant) learning . In the ir attempt to clarify the natu re of reinforcemen t in instrumen tal learn ing, these authors revi ew some of Premack's data and focus on an i nteresting anomaly. In the ir 1 974 study, Tim berlake and Allison demonstrated that simply de­ priving rats of access to performing the less probable response (as defin ed by paired b aseline measures) makes this response (whic h Premack defines as the instrumental response , b ase d on h is differential probability model) effective as a reinforcing contingen t response . For example : rats spend m ore time licking tubes w h ich give them . 4 p ercent saccharin (a non n u tritive swee tener) under paired b aseline meas urement con d itions than licking for . 1 p ercent saccharin . Premack would pred ict that the rate of l icking for . 1 p ercent s accharin s hould increase if this is made the instrum ental response to gain access to . 4 p ercent s accharin . While acknowledging that this does occur, Timberlake and Allison (1974) further demonstrate that deprivin g the rats of the opportunity to lick for . 1 percent s accharin res ults in their lick ing the . 4 p ercent saccharin tubes for longer d urations than measured d uring the b aseli n e period (in o ther words, the . 4 percent s accharin tube l icking h as now become the instrumen tal resp onse and the . 1 p ercent saccharin tube licking has become the re inforc ing event) . They therefore conclude that while the Premack theory is a sign ificant advance over the strengthening of learning theory of re inforcemen t and over the e m p irical law of effect, it is still inadeq uate to explain all aspects of instrumen tal learn i n g . They offer their adaptive m o de l a s a m ore adequ ate theory .

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The adaptive model focuses on the responses* used by an organ ism in gaining access to conseq uences (whic h ultim a tely lead to situations con ducive to the survival of the organsim , such as chew ing food) . The theory s ta tes that these responses are more likely to occur when the organ ism is deprived of the o ppor­ tun ity of access to some consequence . The conseq uences can be appetitive be­ h aviors, which would norm ally be part of a cha in of responses term inating in consummatory behavior (such as drinking), or they can be consumatory re­ sponse s . Hence , reinforcement is a function of depriving the organ ism of the o pportunity to perform a given response at b asel ine (or free operan t) levels . Rather than pre dicting reinforcin g properties on the basis of the d ifferential probabilities of two res ponses as measured by the pa ired baselin e procedure, the response deprivation model bases its predictions on the relative d eprivation from those rates of responding measured durin g the p a ired baseline phase . The power of a re inforcer, so defin ed, is produced by the organ ism's con flict between i ts "need" to emit a respon se which in the pas t h as provided access to conse­ quences, and the lack of opportun ity ( in duced experimen tally by the res ponse depri vation procedures) to emit that response a t basel ine ra tes . I n n ature , the end result of this mechanism is that the organis m is placed in a position where it is likely to survive by either satisfying tissue needs (through eating, drinking, breath ing, and so on) or by escaping aversive conse q uences (such as a bloody encounter with a predator) . The adap tive value of the response deprivation mechan ism may be seen in the following example: A wild cat has to catch small moving things (which are usually rodents and birds) to s u rvive . If prey is scarce, there may be no appropriate targets to elicit the "leaping at moven1en t" instrumental response . The respon se deprivation theory would pred ict that as the cat is deprived of the opportun i ty to em it leap ing and catc h ing res ponses, it will become more likely to engage in other behaviors (such as movi ng to another section of its hunting grounds) to "earn" the opportun ity to indulge in leaping and catching. If such " traveling" behaviors put the ca t in a place where it can emit leaping and ca tching responses (which should result in its catching ed ible prey) , its chances of survival are h igher than they would have been had it no t emitted the " traveling" res ponses . In this example, "leaping at n1ovement" is con tingent u pon the instru n1 ental res ponse of " traveling" and, in turn , the ultimate con sequ ence (eating prey) is con tingent upon "leaping at movement . " A human application of Timberlake's and Allison's ( 1 974) response depriva­ tion theory n1 ight be the fol lowi ng: Before exam s, the clea n ing of your ho use or apartment has to be pu t aside to pern1it adequate study time . As you are de­ prived of the o pportu ni ty to en1 it cleaning responses (which, wh ile of admit­ tedly low p rob ability for son1e of us, n1ay be related in our evolutionary history to avoidance of d isease- transm i tting situations) , the urge to clean becomes stron ger an d cleaning behavior becomes n1 ore reinforcing. If yo u then make clean ing (which, because of depriva tion, h as beco me a re inforcer) contingen t

*

As we w i l l see i n C h ap ter 1 2 , many th eor i s t s now th i n k t h a t response s t h a t are closely l i n ke d

t o s u rv i val may e i ther b e in s t i nctu a l o r b e partly " p rew i re d" s o th a t l earn i n g them i s easier t h an l e a rn i n g o t her res pon ses. T he organism ma y a lso ha ve an i n n a te need to e m i t s uch re sponses .

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u p on the instrumental response of studying (which is p resumably a nonde ­ p rive d response before exams) , you s hould study harder i n order to allow yourself access to some cleaning behaviors . Clean ing would then function as a reinforcer for s tudying responses complete d ! The author, who h as tried this technique and found i t q uite effective, wou ld like to add the following addi tional hypothesis to Timberlake's and Allison's response d eprivation theory of re inforcement: Be­ h aviors which you are force d to emit at levels considerably above b aseline rates m ay become momen tarily aversive . He has found th is to be true in h is own experience (when soc i al p ressures forced him to spend too m uc h time in p erso n al in teraction s, he began to experience socialization as aversive and the idea of getting back to work on th is book as reinforcing) . It m ight also explain the success of forced practice techn iques in behavioral modification . For example, when a sm oker is forced to smoke at levels considerably a bove h is norm al (baseline) rates, he begins to fin d smoking responses aversive . Let u s now turn to t he subj ect of aversive con trol of behavior in general . The Premack principle and the response deprivation model both predict that responses which you want to do (either because of a relatively high operant level or because of deprivation, respectively) can serve as reinforcers for either lower operant level or less deprived responses, respectively. Premack also suggests that the instrumental response in one situation can b e the reinforcing response in another situation.

The Con trol of B ehavior by Aversive Conseq uences Pu n isl1 111 en t Pun ishmen t h as h is torically presen ted greater d i fficulties for learn i n g t heoris ts than either positive con t ingencies or association learning. Thorn d ike revise d h is early symm etrical view of the effects of satisfiers and annoyers to d im inis h the role of pun ishers, an d Skinner spen t more time in polemics against pun ishment t han in punishment researc h . Part of the reason for these d i fficulties lies in the nature of the responses to punishment, which vary from response enh ancemen t (through an arousal effect) to total and p ermanen t response suppression . M uch of the rest of the d i fficulty lies in the varied nature of the procedures that were labeled as p u n is hm ent . Although nega tive reinforcement, or active avoidance , h as been d i fferentiated from p u n ishment, p assive avo i d ance and escape procedures are both consid ered as involving pun ishmen t . Even deliberate rem ovals of positive reinforcers, or time-out proced ures, are usually considered as pun ishers, although this departs from the more common format of a d d i n g a defin ite aversive event to the subj ect's environmen t . In a d d i tion to the s ubj ect's e m itting any operan t responses, such as escape or avo idance, pun ishmen t usually involves em otional or autonomic n ervous s ystem mediated responses-a sign o f a classically conditioned component. In atte mpting to clarify these m atters, it may be use ful to follow a pun is hment situ ation through various sta ge s . The basic para d i g m for con t i ngen t pu n is h m e n t is si1n pl e a n d s tra i gh t- forward : a specific re sponse, previ ously acqu ired and m a i n ta i n ed by posi tive re i n force-

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m en t , is followed by a nox ious stimulus . . . . In fac t, the same behavior is often m a i n tained under concurrent schedules of aversi ve and posi tive con trol . This state of affairs, i n the laboratory as in d aily life, is commonly design a ted as confl ic t . [Kanfer and P h i ll i ps, 1 970, p . 350]

Thus, from the begin n ing, the effects of pun ishment are t he end result of an interaction between the positive consequences and the strength of the aversi ve even t . We h ave already defin e d ( C hapter 3) p u n is hm ent as the add ition of an aversive consequence that results in the reduction of a tendency to perform a re sponse . As w e shall see , this sup p ression d e fin ition, while generally useful, does not describe all types of p u n ishment. In gen eral, with punishment, we are very concern ed with the behavior we wish to eliminate but are less concern ed with the hows of the s ubj ect's term ina­ tion of the aversive events . Thus, all p u n ishmen t involves a d esire by the p u n ­ ishers t o inhibit a p articular response ( by whatever m eans n ecessary t o stop the s ubj ect from doing that which you wis h it no t to do), although this procedure m ay not always have the desired effects . For example, l aziness in a student m ight be treated by presen ting h im with lou d h an dclaps behind the head e very time he is cau ght dawdling, as a p u n ishmen t . How he forces himself to p ay attention is i rrelevant to the pun is her, and there is always t he danger he m ay sim ply look like he is paying atten tion withou t actually learning anything. We have already men tioned that schedule variables influ ence the effects of positive reinforcemen t more than amoun t- of-reward variables . Intensity of the aversive stim ulation , however, is h ighly related to t he effects of pu n ishmen t. Solomon (1964) has described t he effects of d ifferin g stren gths of aversive conse­ q uences in a p arame tric fashion . These results are depicted in Figure 9 . 2 . With very weak punishment, the pri mary effect is arousal, resulting in a net increase in rates of the unwanted response . An example n1 ight be tell ing a child who is " acting out" (the c urrent euphem ism for a child's ra ising hell) in a m ild voice to please quiet down . The extra atten tion n1ay actually serve to enhance the re­ wards of misbehavior. I f the aversive consequ ence is a little n1 ore severe , the effect will be a modest suppression of t he desired res ponse, followed by em is­ sion of the "lost" responses during the n ext pun is h n1 en t- free session (a case of behavioral con trast) . Still more extreme pun ishment ten1 porarily elimin ates t he unwan ted behavior totally, but behavi oral contrast s till occurs during periods of nonpun ishment. Extren1 e pu n is hm ent el i m inates the pun ished res ponse for p ro­ longed periods of tin1 e and, i f trauma tic enough, may result in the subj ect's learn ing ( via reward n1echanisms) avoid ance responses (passive) w h ic h p revent extinction of the cond itioned (classically) fear response prod uced by the pun­ ish n1en t procedure. This is , of cou rse , the si tua tion described by M iller and Dollard as inducing neurotic fears in the i r patients . * Th is s tate is also the desired on e following aversive therapy for bad hab i ts (described in Chapter 8) . I t follows fro m the foregoing that for punis hm ent to be effective, it m ust be severe . S everity, however, is not just a fu nction of the stimulus characteris tics of

*

M i l l er a n d Doll ard actu ally t h eori zed t h a t t h e fear d ri v e is l earned b y d ri ve re d u ct i on .

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Fig ure 9 . 2 A n idealized illus tra tion of the rela tionsh ips be tween the s u bjec tive severity or s treng t h of an aversiv e conseq uence and t h e ra tes of the p u nished belwv ior to be expected: be­ fore p u nis h m en t (baseli n e or opera n t level ) , d u ri ng p re sen ta ti on of the p u n ish ing (av ersive ) conseq uence, a nd after termina tion of the av ersiv e conseq uence tlz a t was con ti ngen t u p o n emission of the p u n ished response .

the aversive stimulus . I t also is d ep en dent u pon the previous h istory of the subj ect. Exposure to punishmen t tha t begins w i th very low intensity and gradually involves increasingly extreme aversive conditions is effective i n shap­ i ng resistance to punishment. If a very weak aversive cue is paired with a s trong positive reinforcer, the aversive cue may even become a con d i tioned 5 0 and the con d i tion labeled "con d i tioned masoch ism " will result . If the aversive cue then becomes gradually stronger, the subj ect may actually seek increasing l evels of p u n ishmen t and experience them as pleasu rab l e . To help o ther users of p u n ish­ men t avoid the d isastrou s effects of such m ishan dling o f aversive con tingencies, Azrin and Holz h ave provided a l ist of 1 3 sugges tions to be followed i n m aking the u se of punishment effec tive . Th is l ist is reproduced in whol e as follow s : ( 1 ) The p u n ish i n g stimulus should b e arranged i n such a m a nn er tha t no u n a u ­ thorized escape is possi ble. (2) The p u n ish i n g stimulus should be as i n tense as possi ble. (3) The frequency of p u n ishment s hou l d be as high as possible; i deally the p u n ishi n g stimulus shoul d be g iven for every res ponse . ( 4) The p u n ish i n g stimulus shoul d b e del ivered i mmediately after the response . ( 5 ) The p u n i s h i n g stimulus should not be i ncreased grad ually but i n troduced a t maximum i nten ­ s i ty . ( 6) Exten ded periods of p u n ishmen t should be avo i d e d , es pec ially where low i n tens i ty of p u nishmen t is concerned, since the recovery effect may thereby occur. W here mild i n ten sities of p u n ishmen t are use d , it is best to use them for only a brief period of time. (7) G reat care should be taken to see that the delivery of the p u n ish i n g stimulus is not d i fferen tially assoc iated w i th the delivery of rei n forcemen t . Otherw ise the p u n i s h i n g stimulus may acq u i re condi tioned rei nforc i n g properties . (8) The delivery of the p u n ishi n g stimulus should be made a signal or S n that a period of ext i nction is i n progress . (9) The degree of motivation to emit the pu n ished res ponse s hould be red uced . ( 1 0) The fre-

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qu ency of posi tive re inforcement for the pun ished res ponse s hould s i m ilarly be reduce d . ( 1 1) An alterna tive res ponse shoul d be m a d e ava ilable wh ich will not be pun ished but which will produce the same or grea ter reinforcement as the pun ished response . ( 1 2) I f no altern a tive response is available, the subj ect should h ave access to a different situa tion in which he obtains the same rei n­ forcement w i thou t being punishe d . ( 1 3) If it is not p ossible to del iver the p u n ­ ish ing stimulus i tself after a response, t hen an effec tive m e thod o f pun ish m en t i s s t i l l availab l e . A con d itioned s t i m u l u s m a y b e assoc i a ted w i th t h e a versive stimulus, and this con d i tioned stim ulus may be delivered fol lowing a response to ach ieve con d iti oned punishment. [ Azrin and H ol z , 1 966, p p . 426-427]

While such elaborate considerations for the successful use of p u n ishmen t would seem excessive , the h arm ful conseq u ences o f p oorly used p u n ishmen t require they be given careful attention . Azrin ( 1 967) h as fou n d that a wide ran ge of animal species respon d to unavoidable shock by attacking any avail able targets. He suggests that this pain- agg ression resp onse is reflexive and i nn ate . Hutchinson and Emley ( 1977) h ave replicated th is effec t with squ irrel monkeys in a test environmen t contain ing a rubber hose , response lever, and a water spout. S hock delivery produced preshock lever- pressing an d pos tshock bi ting-attack ep isodes directed at the rubber hose . As a further complication , water- deprived monkeys followed bi ting responses with drin king beh avior (from the water spout) . Removing the opportu nity to a ttack the hose increased the levels of the alternative behavior of postshock drinking . Could increased drinking of alcohol ic beverages by members of a losin g football tea m (assumed to be pu n ished by their loss) after the game (when opportun ities for socially sanctioned attack behaviors are no longer avail able) res ult fro m sin1 ilar mecha­ n isms? The general issue of the effects of punishment procedures on al ternative (unpun ished) responses will now be discussed in terms of D u n ham's ( 197 1) theory of punishmen t . Dunham notes that two assump tions have tradi tionally been used t o ex plain the suppressive effects of punishmen t . The first was Thorn d ike's nega tive law of effect, whic h states that annoyi ng events weaken the S-R bonds preceding that even t . Following Thornd ike's rej ection of this assum ption in favor of the trun ­ cated l a w of effect (wh ich stresses satisfiers), it has largely been d iscarded . The second assun1ption states tha t the decren1ent in the beha vior suppressed by punishment is related to an increment in some al tern a tive behavior. M ost con­ temporary expl anations of pun ishn1ent s u ppression are ela bora tions of this al ternative-response assun1 p tion . These ela bora tions n1 ay be e i ther one-fac tor or two-factor theorie s . Estes a n d Skinner have offered a one- fac tor ap proach based o n the classical con d i tioning of the emotional even ts elicited by the aversive stim ulus to stimuli preceding the punis hment. These en1otional CRs are ass umed to cause suppres­ sion by con1 peting with the pun ishe d response . Miller and Dollard have offered an instru m en tal learn ing theory of punishment-related suppression which as­ sumes that res ponses assoc ia ted with the term ination of the aversive stimulus becon1 e n1 ore probable (through assoc ia tion w i th reductions in pain and/or fear drives) and compete with the punishe d response , resulting in its suppression (in D unham, 1971) .

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Two - factor theory is represented by M owrer's view, which s uggests that fear is first classically conditioned to s timuli associated with the p u n is hed re­ sponse and that the organism then learns instrumen tal responses ( solu tions), which are rewarded by escape from the fear-associated cues and which then elicit the feeling of relief. D unham ( 1971) notes that n either the em otion al p ro­ cesses involved in ei ther type of theory, nor the supposed reinforcers in theories with an instrum en tal compon en t, h ave been consistently measured . Seligm an and Johnston (1973) report that an im als having previously learned escape re­ sponses rarely show signs of fear in the p rese nce of cues sign aling aversive stimulation . D u n ham conclu des that such theories are unsatisfactory and that a wide gap exists between p u n ishmen t research and punishmen t theorie s . To fill that gap , he offers a m ethodological approach to test the implications of existing p u n ishmen t theorie s . H e c alls this ap proach the multiple-response base line proce dure. This procedure contain s elements from both traditional operant (Skinne­ rian) p aradigm s, where a single response is shaped un d er constraints, and the techniques of etholo gy ( to be d iscussed in C hapter 12) , which involve observa­ tions of m ultiple behaviors in a n atural or semin atu ral setting . As an exam ple of his appro ach , Dunham ( 1971) reviews a s tudy conducted in h is laboratory in wh ich nine gerbils (a small d esert rodent from M ongolia) were randomly as­ signed to three grou p s . Each gerbil was placed in a response cham ber with food bin, drinking tu be, and adding m ac h in e p aper ( gerbils will spend a lot of time shreddin g p aper if allowed to do so) , for d aily h alf-hour session s . B aseline of time spen t in eating, drinking, and paper-shreddin g under dep rivation con d i­ tions were recorded , with pap er-shredding filling most of the tim e , followed by eating and d rinking. Then group E was p unished for eating, group P for paper­ shredding, and group D for drinking. The new behavior of gri d - bi ting ap­ p eared in response to s hock and was also tim ed . Dunham ( 1971) suggested that the . response most frequently and immedi­ a tely associated with shock onset would decrease in probability ( be suppresse d) and rem ain below i ts operant baseline , while the response most frequen tly a ssociated with the absence of shock should increase above prep u n ishmen t b aseline levels . J ust as predicted, gerbils pun ished for eating increased the h igh-probability behavior of p ap er-shreddin g and subj ects pu n ished for paper-shredd ing showed an increase in grid-bitin g (both respon ses that were h ighly l ikely to be associated with shock offset) . Of the two gerbils p u n ished for drinking, one increased paper-shredding and the other increased grid- bitin g . The increase i n grid-bitin g behavior (whic h always followed s hock onset and therefore was associated with reductions in shock- produced drives) pred icted by one-process theories d id not occur. Instead, that behavior grad ually declin ed in m an y subj ects . The prediction derived from two-factor theories, that in­ creases i n the altern ative behaviors would be directly linked to suppression of the p u n ished resp onse, was con tradicted by the rap id onset of su ppression and the gradual increase in the altern ative behaviors . Dunham ( 1971) concluded that even tho u gh the an imals were not able to reduce the shock freq u ency, a re­ spon se whic h consistently followed shock from their viewpoint predic ted a lower likelihood of immediately bein g s hocked aga in . Thus, the p rocess respon -

252

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sible for the increases in alternative responses was directly rela ted to prediction variables (expectancies) , as in Rescorla's predic tiveness h ypothesis . Dunham's conclusions about process put h is vi ews closer to the n e o - H u llian p erspec tive of punis hment and further from the Skinnerian ma instream . Skinner ( 1968) has observ e d that p u n is hment may result i n either overgen ­ eralized aversiveness (as when school becomes aversive for a child who is pun­ ished in class) or in unwanted inhibition of desirable as well as und esirable behaviors . Although the technique of removing a m isbehaving child from op­ portun ities to gain reinforcem en t in the classroom would seem more attractive than d irect u se of aversive stimuli, such time-out techn iques can also trigger an aggressive reaction (Azrin, Hu tchinson , an d H ake, 1963) . Excessive use of this type of procedure in the classroom m ay rem ove the m isbehavin g child from exposure to educational exp eriences and , if use d w i th a ch ild who does not fin d the classroom positively reinforcing, i t may actually shape increased " acting­ o ut" behavior. While the complexities of p u n ishment (review Azrin's l ist quoted earlier i n this section) may intimidate the would-be behavior mod ifi er, p u n ishment in its various forms will continue to be used for one very good reason . For all its fau lts, punishment is usua lly the fastes t m ethod for dealing with u nwanted behaviors . Often the target of an unwanted behavior finds that behavior h ighly aversive ; i f escape i s not possible , h e m a y punish the offender to avoid further inciden ts o f the behavior . When active respond ing prevents the occurrence o f aversi ve events based on time con si derations, the paradign1 is the same as that of Sidman avoidance , which has been extensively stu d ied in the laboratory . We will now turn from our d iscussion of punishment to tha t of other forn1 s of aversive con­ trol , beginning with Sidn1an avoidanc e . Punis hment is a complicated paradigm t hat involves from the beginning a conflict between a positively reinforced res p onse and an aversive cons e­ quence. I t may produce very different results . depending up on t he intensity of t he aversive stimuli relative t o t he organism' s his t ory and on t he alternative res ponses available. Result s range from arousal t o t otal s up p ression.

Avoida nce learn ing , Sid111 a n a nd sign aled

Avo id ance learn i ng paradigms can be d i vid ed into two basic categori es : (1) active avoid ance and (2) passive avoid ance . These types were briefly d iscussed in C hapter 7 w ithin the context of Mowrer's theory . Active avo idance involves an i n s trun1 ental response by the organ ism , and so i t has also been labe led op erant avo i d ance . There are two widely used operant avoid ance paradign1 s, S idman avoi dance (discussed briefly in C hap ter 8 in the presen ta tions of Rescorla's and Seligman's research) a n d signaled avoidance. We w i l l begin with a discuss i on of Sid man a voidance and i ts theoretical in1pl ications, and then m ove to an examina tion of resea rch on signaled avoidance, also conducted by S i dman . Sidn1an's first stud ies were done in 1953 . Rats were given electric s hocks a t regular in tervals unless they pressed a lever. Pressing the lever reset the clock con trol ling the shock and delaye d it for 30 secon ds . Fa ilure to press the lever

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exposed the rats to regular s hocks ; p ressing the lever rap id ly prevented the clock from ever "tim i n g out, " whic h meant the rat could avo i d the s hocks to tally . Although training the rats was time consum i n g, most s ubj ects eventually re­ spond e d at h igh stable rates . S hock-shock in tervals could also be set by variable interval as well a s fixed interval schedules, and h igh res ponse rates were still found (Sidman a n d Boren , 1957) . Sidm an 's results and his avoidance learning p aradigm raise some interesting theoretical issues rel ated to the functions of CSs in avoidance learning. In Mowrer's two- factor theory, escape from a CS, an elic itor of conditioned fear whic h was supposed to be a sign for an impen d in g aversive US , was assumed to reinforce avoi dance learn ing. Konorski (1948) suggested that escape from fear cues acted to inhibit extinction of the fear response to the C S . S id m an (1955) , however, observed that when fixed shock-shock intervals were u se d , the rats learn ed to space their responses in a way whic h resulted in efficien t shock avoidance . S ince no exp licit CS was presen ted, such results are difficult to ex­ plain within the context of two-factor theory unless it is assumed tha t rats were able to use the p assage of t i n1 e as a CS to predict when shock was about to be p resented, and responded to these temporal CSs in learning successfully to avoid the s hock U S s . Results s uch as these led Herrnstein (1969) to p ropose a one­ factor theory of avoidance learn ing based on reinforcement mechanisms as an alternative to two- factor explan ations of avoidance learning. According to H errnstei n , the rats matched their efforts to that needed to reduce s hock fre­ quency ; they d i d not respond because of classically cond itioned fear reactions to the CSs and reinforcemen t resultin g from CS offset . Direct evidence supporting the matching hypothesis has been fou n d by Boren , Sidm an , and Herrnstein (1959) , using a signaled avo i dance p aradigm wh ic h resembled S i dman avoid­ ance except that an explicit CS ( i n this case , a buzzer) sign aled 'vhen the US (shock) was about to occur. With th is research d esign , they found that the rates of bar-pressing em itted by their rats were directly rel ated to shock intensity . Further, H errnstein and Hineline ( 1966) found that rats could learn avo idance respon ses with no warn ing CS at all a n d when b ar-pressing only reduced the frequency of shocks rather than eli m in ating the,m . Contrary to M owrer's two­ fac tor theory , there was no offset of a warn i n g ( fear-elic iting) CS to provid e reinforcem en t through fear red uction (escape from the CS) , and therefore no instrum en tal CR could h ave moved forward in time to be energized by fear. Also , shock d elivery was not always d el ayed by l ever p resses, so these responses were not always followed by a rein forcing even t. These authors concluded that their s ubj ects learned whatever responses reduced shock freq uency rather than learn i n g because o f fear of a CS . H errnstein's m atch i n g-reinforcemen t theory of avoidance learn in g has been no m ore immune to criticism than Mowrer's two- factor theory . Bolles and Riley ( 1973) comp ared contingent an d noncontingen t shocking of freezing res ponses and fo u n d no effects of the p u n ishment contingency . Random s hocks in hibited freezing to the same extent as s hocks contingent u pon freezing . They conclude that freezing is an u nconditioned response to s hock not effected by pro gran1med consequences of freezing behavior . Therefore, it is unl ikely that rein forcement

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mechanisms function in the reactions to aversive USs use d in avo idance learn­ ing. As an alternative to M owrer's and Herrnstein's theories, they offer a more cogn itive alternative . They suggest that the animal's perceptions of the situ ation as s afe or d an gerous determ ine when and how avoidance responses w ill be made . A more expl ic itly cogn i tive theory of avo id ance l earn ing has been offere d by Seligman and Johnston (1973 ) , foll owin g their review of research d isconfirm­ ing both Mowrer's and H errnstein's theories. As in Tol m an 's theory, expectan­ cies (in th is case, about when shock m igh t occur) are the basic u n i ts of learning in avoidance p arad igms . These expectanc ies are abou t the contingencies be­ tween responses and their outcomes; therefore, if animals h ave come to expect that an avoidance response will prevent shock, they will make that response with no signs of fear ( since they expect to be s afe following the response) . As previ ously note d , these authors h ave found experienced subj ects to show few signs of fear in the presence of CSs associated with shock . CSs then serve only as signs to arouse expectancies . To fin ish this discussion of l he role of CSs in avoi d ance learn ing, we must note that Flaherty and colleagu es ( 1 977) h ave revi ewed the li terature on both warn ing CSs and reinforcem en t factors in avoidance l earning and have con­ cluded that even tho ugh CS offse t c an facilita te avoidance learn ing in son1 e types o f avoidance learn ing situations, such presumably reinforcing effects are not n ecessary for avo idance . This sugges ts tha t even though fear reduction related to CS offset may sometimes play the role postulated by Mowrer, it is not the mech anism of avo idance learn ing in general. Let us now turn to a d iscussion of other variables involved in responding to aversive events . Both S idman and signaled operant avoidance proced ures are modern labo­ ratory analogs of the old "do this or else" principle . As such, they offer a way to cond uct an experimen tal an alysis of behavior in to variables und erlying m al adaptive responses to aversive contingenc ies . One exan1 ple of such an anal­ ysis was conducted by S i dman ( 1 960), using a modified CER (con d itioned emo­ tional res ponse) parad igm in which the instrum ental response was bar- pressing to avoid avo idable shock, and the expected effec t of un avoidable shocks would be condi tioned facilitation of pressing. Th is is sim ilar to Rescorla's procedure in wh ich the sh uttle - j u 1n ping res pon se was fac ilita ted in his posi tive prediction group (C hapter 8) . Monkeys were tra i n ed on a S i d n1an avoidance schedule with a FI -20 second shock-s hock sche d ule. After the in strun1 en tal avoidance res ponse was learn ed, a clicker (CS) follo wed by unavoidable shock ( U S) was introd uced . The effect of th is add ition was for the n1onkey to increase its response rates during the click ing in terval . W hen the avoid a ble shocks (Sidman con tingency) were term inated, leaving only the un avoidable shocks, th is conditioned facilita­ tion effect p ersiste d . S i d m an suggeste d that from the monkey' s viewpoi nt, l ever press i ng , by w h ic h it has in the pas t effec tively avoided shocks, seem s to re mai n l argely s uccessfu l . Avoida nce of shock s t i ll re i n forces lever press i n g , even though t h e rel a t ion i s a spurio u s on e . The monkey's behavi or d u ring t h e cl icki n g perio d i s nonadaptive because t he rul es of t he env iron m en t have change d a n d the c hanges have not y e t elici ted appropriate response m o d i fica-

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tion . The o ccasional shocks only serve as false d iscrim ina tive cues to keep the an imal be hav i n g in a fash ion appropriate to the former c ircu m s tances . [ 1960 , p . 66]

Such m aladaptive behavior can be seen to be produced in the same lawful fash ion as "normal or adaptive" behavior . S id man suggests tha t such "superstitious" behavior in m an and monkey results from the subj ect's inability to d iscriminate the true p a ttern of contingency relationships between h is re­ spon ses and the aversive even ts . Thus, the develop ment of abnorm al behavior is seen as a product of unfortun ate environmen tal events rather than as a sign of the d isintegration of an inner p ersonali ty s tructu re . It m ust be note d , however, that the m al a d ap tive (since in the late stages of the exp eriment all s hocks were u n avoidable) con d i tioned fac ilitation of the pressin g response eventually van­ ished as the monkeys learned the true state of affa irs . It is characteristic of most S idman avoidance responses that if the response cost is too high, the s ubj ect will occasionally neglect to respond . If such p au ses are n ever p u n ishe d , they will tend to become longer and more frequent. Furtherm ore, in the condi tioned suppression paradigm (C ER) d iscussed i n C h ap ter 8, the subj ects rarely reduced their o verall levels of bar-pressing for food . Ra ther, they cease d p ressin g d uring the clicking interval an d made up the lost responses during the nonclicking in tervals . This m ay represent another demonstration of b e havi oral con trast in a punishmen t situation . Active avoidance (operant avoidance) requires t he subject t o emit an inst ru­ mental response (such as shutt le-j umping or bar-pressing) t o avoid shock . ShoG k is presented on a fixed or vari able interval s chedule in bot h Sidman and signaled avoidance paradigms, which differ only in that a warning CS precedes shock in signaled avoidance, while only internal cues can be CSs in Sidman avoidance.

In this chap ter we h ave looked clo sely a t aspects of the pun ishmen t and avoidance ( ac tive) types of aversive control paradigm s . Let us now sum m arize som e of the relationships of these typ es of aversive control to one another and to the escape an d passive avoid ance proce dures d efin ed in C hap ter 7 .

A n overviezv of a versive con trol

As noted i n C hapter 7 , there are three b asic para d igms for d escrib ing aversive con trol : escape, avo idanc e , and pun­ ishment. In escape, the subj ec t experiences the aversive stimulus but subse­ q u ently gets away from it. I n p assive avoidanc e , the s ubj ect must only refrai n from e m i tting a particular response t o totally avo i d experiencing the aversive US . An example would be a p aroled felon who avoids s pec ified behaviors to keep from going back to j ail . Active avo i d ance, as we saw, requ ires the em ission of some instrumental respon se either before the en d of som e time perio d (Sid­ man avoidance) or after a warn in g signal (signaled avo idance) . Exam ples could be the felon's reporting to h is or her parole o fficer at specified in tervals or actively avo i d in g "bad influences" followin g warn in gs from h is or her parol e o fficer, respec tively.

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Punishment involves the application of an aversive conseq u ence for the emission of a specified undesirable behavi or. In con trast to escape, the subj ect is not able to ge t away from the aversive stimulus by an active response (or the punishment is not really p u n ishmen t, from the viewpoint of the one punis hed) . In contrast to avoidance, the subj ect cannot avoid the aversive stimulus except by not em itting the specified response . Punishment is l ike passive avo idance i n that the subj ect c a n avoid experiencing t h e un pleasant stim ulus by n o t doing some specified act. I t differs from p assive a void ance in tha t the subj ect, i nstead of not approaching CSs which w arn of an aversive US, m u st refrain from emit­ ting a response which is positively reinforced . Aversive stimuli u sed in pun­ ishment may be either even ts causing pain, or the rem oval of a specified posi ­ tive contingency, o r the access to e m i t behav i ors leading to posi tive re inforcers (known as time out) . An example of time out would be making a fou rth-grade pupil sit facing a comer every time he is observed disrupting another child ' s work . I t is assumed that the m alcreant p refers classro om p articipation t o comer watch i n g . A summary of some relationships of the various types of aversive p aradigms is shown in Table 9 . 1 . Finally, i t should b e rep eated that the effectiveness of aversive con trol is hi ghly influenced by the subj ect' s j u dgment of how severe the aversive stimulus really is . This is a function both of the p hysical features of the aversive cue and the subj ect's previ ous h istory of expos ures to such cu es . Subj ects socialized in cultures where aversive consequ ences are a frequen t an d accepted part of child­ hood wo uld be less likely to be sign ificantly in fluenced by levels of punishmen t t h a t som eone coming from a less pu n i tive background would consider severe and a sign ifican t deterren t to an tisocial behavior . An early exposure to accelerat­ ing levels of pun ishment might produce condi tioned resistance to punishmen t . While the effects of aversive con trol are more in fluenced b y intensity factors (taking into account the subj ect's pas t h istory) than positive control, and less influenced by schedule-of- reinforcement variables, schedule variables can in­ fluence the effects of aversive stimuli . McKearney ( 1 972) found that squ irrel monkeys exposed to s hock in a multiple schedule parad igm (a variable interval component and a fixed ratio con1ponent) displ ayed conditioned suppression on the fixed ratio sched ule and no suppression when shock was programmed on a variable in terval schedule . Accord ing to Sidman's research, we have noted, m aladaptive behavi or can be genera ted thro ugh a versive con d i tioning procedures . This raises the ques­ tion of whether 1n aladaptive behavi or can also be reduced wi th aversive s timu­ la tion . One psychologist who th inks so is I var Lovaas, whose use of shock with autistic children illustrates the therapeutic use o f a varie ty of operant aversive con trol proced ures .

Iva r Lovaas a n d a shocking applica tio n of opera n t p rinciples (in Lovaas, e vents can procedures The second

Ivar Lovaas Schaeffer, and Simmons, 1 965) lis ts three ways in which aversive be used as tools in therapy . The first approach uses punishmen t sim ilar t o the aversion therapy approaches reviewed in C hapter 8 . uses the negative reinforcemen t paradigm, in wh ich shock is re-

R ei nfo rcem en t- Related Lean1i11g

Tab le 9 . 1

Effec t of B eh a v ior Increases t arget behavior

Decreases target behavior (suppression)

257

Pa ra digms of Aversive Co n tro l Exp erie11ces A v ersiv e E ven t

If S u ccessful , Does No t Exp erien ce A versiv e E v e n t

E scape

Active avoi d ance

C on d itioned facilitation (some noncont ingent avoid ance)

S i dman avoid ance and sign aled avo i dance

C on d i tioned suppressi on or cond i tioned emotional responses (CER)

Passive avoidance

Pun ishment and time out fro m posi tive re inforcement Th is table shows a system to cla ssify the various paradig m s o f aversive cont ro l . The effects on the organ is m ' s b e h avior ( s u ppre ssion or facili tation of on go i n g b e h av ior) are noted i n t he first col u m n , and

the s u bj ect' s experi e nces o f the aversive e v e n t (for exam p l e , does t h e s u bj ect act u al l y

g e t shocked o n m o s t trials?) a r e n o t e d i n the col u m n he a d s .

moved or w i th held contingent u pon s p ec i fied b eh avi ors ( negative reinforce­ m en t was d iscu ssed in Chapter 4) . The t h ird u ses con d i tioning S 0s to pain red uction , w ith the goal o f having S 0s becom e cond i tioned positive reinfor­ cers or s ign als for the ab sence of pai n . We have seen that Dunham found th a t h is s u bj ects i ncreased the ir rate o f e m i tting altern ative b ehavi ors associ ated w i th shock o ffset, or the ab sence o f shock . Accord i n g to Lovaas 's model, the effects of this th ird k ind of aversive p rocedure would b e an i ncrease i n p os itive altern a­ tive b e h aviors, as a p arado x ical by- prod uct o f p a i n ; th is would cause p ersons w i th a " safe ty- p red icting" cue value to b ecome conditioned posi t ive rei n ­ forcers . L e t u s now examine Lovaas' s work w i th i n fa n t ile autis m and h i s results. C h ildhood au tis m is o ften classified as a sub typ e o f ch ildhood psychosis . It is ch aracterized by self- s timulatory b e h avi ors, wh ich m ay b e self-destructive, and a gen eral lack o f social res p onsiven ess . Autis t ic ch ildren d o not respon d well to trad i tional psychotherapy . Therefore , shock procedures were u sed as a last resort . I n the first experim en t ( Lovaas et al. , 1 965) , the ch ildren (two five year olds) were placed barefoot on a shock grid flo or and escape- avoidance proce ­ dures were i n itiated . O n e o f the exp erim en ters s tretched out h is arms and s a i d , " C o m e here . " A ny m ovemen t towards t h e experim enter term inated t h e s hock for th a t trial . If the ch ild d id not move, the second exp erimenter p u shed h im in the d irection o f the firs t experim enter (wh ich also term i n a ted the shock) . Th i s escape p h ase was followed b y an avoid ance procedure in w h ich s hock was w i th held i f the ch ild approached the experim en ter w ith i n 5 seconds after the com m a n d , " C o m e here . " Shock w as also used to pun is h self- s t imulation an d/or tan tru m behaviors . The verb al comm and " N o ! " was assoc i ated with s hock and ac q u ired l i m i ted effectiveness as a c on d i t ioned aversi ve re inforcer . It was found th a t not only did the ch ildren le arn to come to the exp erimen ters to avo id or e scap e shock, b u t that the verb al command "Come here" becam e effective i n

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environmen ts where shock was p oten tially ava ilable ( the problem o f s ubj ects learning to discrin1in ate when shock was likely to occur d uri n g aversive cond i ­ tioning p rocedure s was d iscussed i n Chapter 8) . A s predicted by Lovaas, alter­ native behaviors d id appear. Surp risingly, the se included seeking the ex­ p erime nters' com p any, s howin g affe ctio n , and incre asing the ir alertness to the envi ronm ent. Lovaas and colle ague s (1965) commented that d urin g successful avoidance tri als the childre n " ap p eared happy . " T here was also limited gener­ alizat i on of the adult - seeking and affection ate b e h av i or to situations outsi d e the chock- avoidance training e nvironmen t . Lova as tested the h ypothesis that the adults who h a d b een assoc iated with safety from s hock following avo idance tri als and h ad h ugged and fondled the children when the ch ildren ap proache d them would beco m e con d itioned posi­ tive reinforcers . The children were taught to o p erate a candy d ispen ser wh ich gave them b o th candy and a view of the experim en ter's face . During exti nction tri als (no more can dy) , the pho tograph of the face of the exp eri m en ter ( asso ­ ciated with shock re duction) was more effec tive in slowing down the rate of extinction than pho tographs of other faces . In add ition , ward nurses re ported that following the s hock avoid ance training, the ch il dren b egan , for the first t ime, to come to them for comfort when they were h u rt i n play . O n the n egative side, Lovaas and colleagues ( 1 965) noted th at the positive shock- produced changes in beh avior were o ften h ighly situat ional in n ature (s howe d lim ited generaliz ation to n ew environm en ts and peopl e) an d extingu ished rap idly . This su ggests that even though aversi ve operan t tech niq ues m ay be useful in manag­ ing autistic ch ildren , they d o not "cure" autisn1 . Lovaas ( 1 974) , it should be noted, is deeply concern ed with the e th ical and practical iss ues surro un d in g the u se o f ex tre n1 e aversive techniques such as s hock . First, he recom mends the ir u se only for dealing w i th extreme be havi or s uch as self- m u tilat ion (some autis tic children have li terally chewed fingers o ff) and to tal lack of respons iveness to other peopl e . In these cases, shock can i n h i b i t destru ctive be havior that form erly h a d been rei n forced b y adults who h a d l e t the child have his or her own way to avo id ten1 p er tan tru m s or self- m u tilation . Secon d , he reco mm ends that therapists using aversive tech n i q ues sho uld have a deep love for children , be patient eno ugh to p rovi de l arge doses o f affection for positive behavi or, and be willing gra du ally to s h ape desired behaviors th a t can compete with the destructive beh aviors . Finall y , he suggests tra ining the par­ en ts o f au tistic c h ildren in o perant con trol procedu res ( i nclud ing aversive tech­ n iq u es) so that these paren ts can overcome their own fee l i ngs o f ineffectual ity and fru stration to the poin t where they can s uccess fully ma nage the behavior of the ir autis tic ch ildren in the ir own homes . This involves both s howing the parents how paying atten tion to tan tru n1 s and se l f- mu tilation may have re i n ­ forced these behaviors and coach ing the paren ts t o "load the ch ild u p with love " for posi tive beh avi or . H e teaches the parents that su ppressing bizarre be havior (such as self- n1utilat ion) through aversive con trol provides the o pportu n i ty to begin building up appro priate behavi ors wh ich eventu ally allow the c h ild to mee t h is or her needs in nonpa tholo gical ways .

R einforcemen t - R elated Lea rn ing

259

U sing punishment and avoidance procedures with autistic children, Lovaas was able to increase their attention to people ; he found that positive alterna­ tive social behaviors increased as withdrawal was suppressed. H e also found that experi menters associated with shock reduction became conditioned positive reinforcers for the children.

G et ti n g c h ildren to p ay a tten tion to adults an d to fin d them positively re in­ forci n g is a prereq u isite for ch ildren to i m i ta te adults . This i m i ta tion , or model­ i n g, of adult behavi ors is a primary learn i n g m echanis m i n social learn ing theory , w h ich w ill b e presented next.

So cial Learn ing Theory As we saw in C hap ter 8 , the m aj or d irection of the n eo - Pavlovians in the Soviet U n ion was away fro m animal research and toward cogn itively orien ted work on the secon d sign al sys tem . In C hap ters 3 and 7, we exam ined the increased o p enn ess to cogn itive variables s hown b y the n eo- Hullians-Sp enc e , M i ll er, Dollard, and Mowrer . The p arallel movem ent w i th in the Skinneri an tra d i tion , now called social learning theory, has i ts forem ost advocate i n Albert Ban dura . The social learning theory movemen t is p ara llel i n som e re spects to Tolman' s e fforts to combine rigoro us experi m en ta tion , a b e havioris tic viewpo int on the m echanisms of learn ing, an d cogn itive u n i ts of learn i n g . Social learn in g theory i s d is ti n gu ished by several explicit ass um ption s : 1 . Most h u m an behavior i s l earned rather than i n n a te , an d most behavior ( in ­ c l u d i n g m aladaptive behavior) is controlled by environ men tal i n fluences rather than by i ntern a l forces . Therefore, posi tive rei nforcemen t-the modifi­ cation of b e h avior through a l tera ti on of i ts reward i n g o utco mes-is an i m ­ portant procedure i n behavioral therapy (Bandura, 1967) . 2 . The princi ples and laws of o peran t learn ing developed by Skinner and the orthodox n eo-Skin nerians are the l aws of perform ance an d of much h u m an l earn i n g . The techni ques used are those of o pera n t con d i tion ing, wh ich was d eveloped l argely by Skin ner and his colleagues at H arvard U n i versity (Ban­ dura, 1967) . Thus, Band ura's theory is i d en tified as being of the behavi oristic trad ition , a n d applica tion s of social l earni n g theory, of the behavior modifi­ cation movemen t .

B a n d ura (1977) h as taken the p osi tion th at the effect of rein forcement on p erformance is not that of an a u tom atic shaper of human con duct. Rather, he sees h um an s as u si n g i nform ation abou t reinforcement contingencies to regulate their b ehavior. Awareness plays a crucial rol e i n th is process . 3 . The in tern a l represen tations of l earn ing are rarely S-R rel a tion sh ip s . I n s tead , they are e i ther i mages of events or secon dary coded sym bols sum marizing an d categorizing even ts . Therefore, while mos t of the m echanisms of learn ­ i n g are behavioristic in form , the con ten t of learn ing is cogn itive . 4 . Although h u m a n s can learn through d irec t re inforcemen t an d shaping pro­ cedures, a m ore efficien t learn ing mode is observa tional learn in g . O bserva­ t ional l earning is the basis for most th ings learned fro m o ther h u m ans (hence

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the label "soc i a l " learn ing theory) , such as langu age and soc ial rol es and norms . This is also called vicarious learning, or modeling. Mod els can be humans or represen tations of humans, such as dolls or p ictures (Ba n d u ra , 1967) .

Other Skinnerians have attempted to expl a in im itative or modeling behav­ the d is cri m i n a ­ s r, where S d R i or throu gh the followin g parad igm : S d the overt matching t ive s t i m u l u s for model ing or the m od elin g s t i m ulus, R the reinforcemen t provi ded by response performed by t he ob server, a n d 5 r som e agen t for i m i tation . This explanation is sim ilar to that a dvanced by M i ller a n d Dollard (see C hapter 7) in vi ewin g frequ ency of i m itation as dependen t u pon the level o f reinforcement pro duced b y successful copying o f o thers' be­ havi ors . B an dura dis agrees with this p arad igm for the following reason s : -

=

-

=

=

The scheme . . . does not a ppear applicable to observa tional learn i n g \Vhere an observer does not overtly perform the m odel's responses in the se tting in which they are exh ib i te d , re inforcements are not adm i n i stered e i ther to the model or to the o bserver, and whatever responses have been thus acq u i red are not d ispl ayed for days, weeks , or even m on ths . Under these cond i t i ons, which represent one Sr) i n the of the mos t preva len t forn1s of soci a l learning, two of the factors (R three-elemen t paradigm are absent d uring acqu isi tion , and the th i rd fac tor (S d or modeling stim ulus) is typ ically m issi n g fro m the si tuation when the observa­ tionally learned response is first performed . [ 1971 , p . 6 ] -4

fur Ban d ura , modeling reflects s ym b ol ic processes that occu r d u ring exp os ure to the modeled activities before ei ther the em ission or the rein forcement of any i m itative responses . 5 . The prim ary effect of re inforcernen t is to provide the person w i th i n formation abou t cond i ti ons l i kely to yield re inforcement i n t he fu ture , n1uch as in Tol man's theory . K nowledge of reward acts to prov i d e incent ive motiva ti on , as in H u ll's and Spence's theories . T he person's emotional responses to this inform ation act l i ke M owrer's " ho pe " variable i n setting the stage for the performance of a response . As we will see in the nex t sec tion , re inforcemen t affects every s tage of the modeli ng process . I ts functions are both n1ore com­ plex than the theories sugges ted by the ortho dox Ski nnerians and less automatic .

To s u m m arize to th is point, Band ura has ado pted some of the laws a n d assun1 p tions of o pera nt learn ing theory . H e then moves t o the cogn i tive position in s u gges ting that cogn it ive un its are learn ed and much learn i ng is associ at ional and sym b ol ic . In s uggesting that 1n odel ing is the pri mary learn ing m o de for humans, Band ura attacks both the ass u n1 ption th at l earn i ng occurs automat­ ica l ly because o f re inforcen1ent and the eq u i potentiality ass u mption s held by most o perant learn ing theoris ts . Bandura divi des i n1 i tative learn ing into fo ur processes . These are : 1 . A t tcntio 1 1 a / p ro cesses : B e fore so n1e one or son1ething can b e n1odeled, the s u b­

j ec t m ust no tice thern . What is noticed i s a func tion of previ ous re inforce­ ment; s pec i fic perceptual hab i ts are s haped by rewards rece ived wh ile " a t­ tend ing to" spec i fic ges talts . This " a ttend i n g to" n1ay be s haped i n by a

R einfo rcem en t- R elated Lea rning

therapist. Band ura ( 1967) c ites Lovaas's work with autistic children , i n wh ich visual a ttent iveness to the therapist was shaped b y e ither avo i d a nce o f aver­ sive consequences or food reward . This reinforcement of notic ing the therapist was n ecessary before further con di tion ing could p rocee d . We may also a ttend to someon e else's b e ing re inforced, and t h is "vicarious" rei n ­ forcement may d eterm ine who is t o b e watched and modeled . Band ura ( 1969) has reviewe d the characteristics of m o dels who elic i t attention . M od els who h ave d e m on s trated h ig h c o m pe tence , "who are p u rp orted experts" or celeb­ rities, a n d who possess status-conferring sym bols are likely to command m ore atten ti on than models defic ien t i n these a ttributes. O ther variables that may affect attention incl u d e : a ttractiveness, ethnic i dentification, sex , and age . Some of these may i n teract i n complex ways . Although most stud ies with older primary children h ave fou n d tha t c hildren are likely to model same-sexed models m ore accura tely, a n d tha t males are generally m ore effec ­ tive m o d els , Bartlett ( 1 977) foun d that first- a n d sec on d - grade children all m o d eled female m o d els (adu lts) m ore accura tely. Males watching male m o d ­ els i n a m ovie d i d least well i n accura tely reprod ucing a p yram i d o f wood en blocks . Modeling behav i or i n general, or m o d eling of spec i fic types of m o dels, may b e i ncreased by selective reinforcem en t (M iller and Dollard , 194 1 ; Ban­ d u ra , 1 969) , a n d beneficial change i n nonbehavioristic t herapy may b e t he result of the client's modeling of the " healthy behaviors" o f the therapist (Ban d ura, 1 967) . One assumes that this latter m o d eling is h ighly rein forced . To s u mmarize the relative effects o f reinforcem en t and m o d el attributes on atten t i on al processes, B an dura states : I n d ee d , incentive contr ol of observ i n g b ehavi or can, i n most i n s tances, over­ ride the effects of varia tions in o bserver c harac teristics a n d m od el a ttri bute s . I t should b e noted, however, tha t i n the present t he ory reinforcem en t vari­ ables, to the extent tha t they influence the acquisi tion process, do so princi ­ pally b y augmenting a n d susta i n i n g a tten tiveness t o m o d eling cues . (1969, p p . 137-138 ]

2 . R e ten tional p ro cesses: These are the processes b y w h ic h the modeled behavior becomes encoded as a m e m ory b y t he observer . W hile Ban d ura (1969) re­ views studies d e m onstrating what a p pears to be contigu i ty learn i n g , he feels tha t e i ther o vert (wh ich allows external re inforcem ent) or c overt rehearsal can considerably enhance the stabilization a n d s trengthen ing of acqu ired re­ spon ses a n d observ ational learn i n g . Re i nforcement i n this process acts to i ncrease the frequency of rehearsal of modeled responses assoc i a te d w i th rewarding outc ome s . I ncreased rehearsal does m ore than j ust "stamp in" m o d eled responses . Band ura assu mes tha t rehearsal helps reinforce m odeled responses by active processes and not by sheer repetition . Rehearsal of a m odeled respon se protects i t fro m i n terference fro m other possible responses . Practicing a response, e i ther overtly or covertly, lets the person doing the practice see if he or she is doing the response as m uc h like the model as possible . Th is, in turn , helps the m o d eler focus h is or her a tten tion on the cues for m o d eling m ore i ntently . Two representational system s are i nvolved i n h u m an m odeling : i m ag­ inal a n d verbal. The imaginal system is o perative during exposu re t o m od eling stimuli : Sequences o f c orrespon d ing sensory i m ages are assoc i a te d on the

261

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basis of physica l con tig u i ty . Essentially, the s tored i mages act as cogn itive n1aps (as i n Tol man's theory) to guide the observer in i m i ta t ion . The verba l system i s a sy mbolic syste m ; as such , i t repre sen ts coded or derive d informa ­ tion . I n suggesting t h a t the most effic ient learn ing involves transl ating action seq uences i n to ab breviated verbal systems a nd grou p i ng cons tituent p a t­ terns of be havior i n to l arger i n tegra ted u n i ts, Band ura (1969) is ta k ing a s trong molar, cogn itivist posi tion .

3 . J\1 o toric Rep ro d u ctio n : This th ird maj or componen t of the modeling process involves the tra nsl a tion of the sym bol ic (cogn i tive) re presenta tions of the m od eled stimuli i nto overt motor acts, or actually perform ing the modeled be havior. A s the person a ttem p ts to translate his idea of what he tho ught he saw the model do, he checks h is performance agai n s t his mem ory of what he saw modeled . Such m otoric reprodu c ti on is l ike the shap ing of overt behav­ i or through reinforcement from the environ men t, except tha t in th is case the rei nforcers are the person's i nternal reinforcers arisi ng fro m the feel ing tha t h e has c o p i e d t h e acti on as accurately as possib l e . Motoric reproduction a n d ob servational learni n g in general are l i m i ted b y the extent to which component re sponses are already learned . It is easiest to learn from wa tching a professi onal play tennis i f you already are fami liar wi th many o f the re q uired m ove ments and know wha t to look for . It is easiest to learn from a model and to reproduce his or her act i ons a ccurately when all you are req u ired to do is to synthesize previously acqu ire d re sponse pa tterns i n to the new com plex b ehavior exhib i te d by the model . Motoric reproduction is a lso i n h ib i te d by p hysical d i fferences be tween t he model and the person doing the model ing . This author is not going to play b asketball l ike Wilt the S tilt, regardless of his efforts a t re hearsa l . F i n a lly, situations in w hich it is difficult to observe the s u b tle movements of a model m ay i nterfere with subsequent m otoric reproduction . 4 . In cen tiv e a n d M o tiva tion al Pro cesses: The roles of re inforcement are far m ore complex than in Skinner's theory . Re i n forcement d eterm ines \Vh a t is noticed, wha t is m odele d , wha t is rehearsed (\vhich s trongly i n fluences reten tion) , and what behavior is e m i tted . While Bandura does not see re i n forcen1ent as a d irect learn i ng variable, the ex pecta ncy of reward (or avo id ance of aversive conseq uences) is necessary for a behavior to be e m i t te d ; posi tive i ncen tives are req u i red for an overt expression of m a tc h i ng be havior to conti nue to be ex pressed . Thus, re i nforcem ent has both i m porta n t " i nforma t i onal" proper­ ties for learn ing and d i rect effects on performanc e . Of course , the re inforce1n ent for m a tc h i ng behavior m ay be vica rious or i n ternal (as knowing that yo u performed a response correctly) .

The ra nge o f situa tions in wh ich n1 odeling procedu res may be used is vas t . Band ura (1967) has reviewed cl i n ical applica tions ranging from the u se o f dolls to red uce hyperaggressive reactions in ch ildren, to therap is ts h aving pa tients " try o u t" d esirable behaviors n1 odeled by the therapis t . These s tu d ies, taken toge ther with o ther work concern ing the i n fluence o f vicarious rein forcemen t on aggression , contradict the Freudian view which postulates th a t aggressive acts are benefic ially cathartic . In real l i fe, wa tch ing violence may encourage vi olence . Bandura ( 1 962) d e n1 onstra ted th at children w ho were frustra ted were m ore li kely to beh ave aggressively a fter observing a n1 odel behave in an aggressive

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m anner . Let u s now turn to the more pos itive side o f the m o deling pheno menon-its e ffectiveness in a ppl ied areas . Modeling p rocedure h as been s uccessfully e m ­ p loyed in two m aj or areas . The first o f these is teac h ing s m all ch ildren . A study b y M artin ( 1 975) illustra tes the basic proced ure . Two re tarded c hil dren were exposed to d aily im i ta tion tra ining in w h ic h the te acher or a n urse modeled and i n s tructed each child to i m i ta te 1 2 sentences containing one of six animal n am e s . Praise was give n for correct verb al im i ta tion . Each of the sentences also con­ tained descri p t ive adjectives rel ated to the color an d/or size of the animals . During probe sessions a t another time o f d ay an d in a different environment, the childre n were a sked to d escribe 12 picture s of animals different fro m those described d uring the mo deling session s . Not only were the children able to i m itate the sentences modele d , b u t the adj ectives u se d generalized to the new an i mals ' p ictures . The second area of application h as b een in the cl i n ical are a . B an d ura , G ru sec, and M enlove ( 1967) trea ted ch ildren with dog phobias by exposin g them to peer mo dels who in teracte d in a p rogressively more fe arless m an n er w i th a dog. At the end of e ight 1 0 - m i n u te sessions held over fo ur days, the m ajority of the ch ildren in the mo deling trea tm en t grou ps were ab le to approach e ither the original stimulus dog or another dog, fee d the m , and re m ain alone i n the room with them . Th is stu dy s hows two i m p ortan t in novations over sim ple modeling: (1) the ch ildren were treated in groups of fo ur, wh ich is a more e ffic ient approach than i n dividual tre atm ent of p hob ics, and (2) progressive modeling was used, wh ich Bandura feels reduces i n itial fe ar and fac ilitates the s p ee d of tre a tment. Progressive m o deling u se s a gradu a ted series of mo deled b eh aviors parallel to the fear stimuli h i erarch ies used in s ystem atic d esensitiza­ t ion . G ro u p tre a tment m ay b e even more effective than in dividual treatm e n t . N e m etz, Craig, and Reith ( 1978) trea ted women sufferi ng from debilitating sexu al anxiety by the process of symb olic modeling, using videotapes . Tre at­ ment began with relaxation tra i n ing, followed by the viewing o f 45 vid eotaped vign e ttes depicting graduated sexual behaviors . The 16 experimental s ubj ects were ran domly assigned to e ither ind ivi d u al or group tre atment. There was a trend towards gre ater i m provem en t (d ecreases i n anxiety and increases i n sex­ ual behavior) in the subj ects who rece ive d the gro u p tre a tment, although the i n d ividual tre a tm en t subj ects also i m prove d . The six control s u bj e c ts s howed a slight trend towards de terioration . Wh ile th is s tu dy shows sym b o l ic modeling to b e e ffective , most recent a ttem p ts to re duce phobias h ave involved a tech­ nique usually referre d to as particip ant model ing. I n th is proced ure, the therap ist dem onstrates the first approach to the feared o bj ect or s i tu at ion wh ile imparting verb al inform ation . The s u bj ects are then as k e d to practice the a p ­ proach ( w h ic h reflects the first s tage o f the d esensitiz at ion hierarchy) . This is followed by the therap ist's modeling of the next s tage of the h i erarchy, with the s u bj e c ts aga in prac ticing overcom ing the ir avoidance b e haviors, and so o n . Sm ith a n d Coleman ( 1977) fo u n d subj ects ( 1 7 fem ales with rat phobias) i n all their treatmen t gro u p s to s how improvement on se veral me as ure s ( behavioral

Applica tions of 1nodeling

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M odern Con ten ders

approach tests, fear indexes, reactions to a ge neralization rat) . S ubj ects, ho w­ ever, who had self- d irec ted practice fol lowing the form al p artic ipant-modeling proced ure s howe d greater i mprove ment th an s ubj ects who received add it ional therapist-directed practice (overlearn in g gro u p) , espec ially w hen exposed to novel rats of new breeds (with different-colored coats) . Before leavin g this b rief s urvey o f varia t ions on the mo deling the me, let us b riefly examine one more modeling techniqu e , known as self-modeling. This tech n i q u e consists of havi n g s ubj ects o bserve video recordi n gs of themselves perform i n g target b e haviors . Using th is proce dure w i th hospitali zed ch ildren , Miklich , C h i da , and Danker- Brown ( 1 977) were a ble to i m prove b e d - m aking behaviors i n the ir 1 2 subj ects, without the s ubj ects reporting any awareness of their behavior b eing changed or even that the purp ose o f the vi deo recording was to affect them . This result is curious, consi dering that M ichael D awson a n d others (reviewed i n C hapter 8) h ave shown awareness to b e a prereq u isite for most h um an classical con d itioning (which has trad i t ionally b een consid ere d a simpler form of learn i n g than modelin g) . Altho ugh Bandura's theory of modeling represents an in teresting syn thesis of concepts derived from the connectionist and cogn itive le arn ing tradi tions, the model ing process seems to h ave grea ter generality than j ust to human learning, i n spite o f the co mmon view that h um ans u se more cogn i tive - do m i nated pro­ ' cesses in le arn ing. Band ura ( 1 969) h as fo u n d mo deling to occur in dogs and Old World primates, and R iess ( 1972) was even able to dem onstrate a modeled accel­ eration o f avo i d ance res p on di n g in rats, using a classical condition i ng p aradigm . Vicarious extinction w as also dem ons trate d when the model rat no lon ger received s hock (the US) after a l ight (the CS) and the response rates o f the o b server rats eventually re turn e d to baseline l eve ls . These dem onstrations of le arn i n g without overt re inforcement a ga in point out the inadeq uacies of law­ o f- effect- derive d theories about the n ature o f reinforcement and learn ing pro ­ cesses . Viewed i n terms of adap tive models o f the na ture and function o f re in­ forcem ent, any soc ial organism able to learn from watching s uccessful be haviors em itted by o ther mem bers o f his or her gro up would be more l ikely to s urvive than an an in1al dependent upon i n d ivid ual trial and error for learning. S uch an in terpretation fi ts n icely with the adaptive mo del proposed by Ti mberlake and Allison , and we will return to the an alysis o f learn ing in term s of evolu tionary variables in C hapter 12 . Bandura has proposed a theory in which the primary mode of learning in higher organisms is imitation or modeling of others in the environment who have certain characteristics. such as control of the modeler's future reinforcements. The four processes involved in modeling are : attentional, retentional , motoric reproduction, and reinforcement mechanisms. Many modeling procedures are used in therapy, including graduated modeling, participant modeling, and self-modeling.

Chapter Perspective We have revi ewed adva nces in neo-Hullian and three types of n e o-Skinnerian the ori es and principles . We have seen many advances in d isco vering new prin -

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ciples and ap plicable tech n i q ues . Yet the search to d evelop a satis factory theory about i n s trumen tal or o pera n t learn ing has not y e t led to a generally accepted theory o f how reinforcement works , l e t alone what re inforcement is . If t here is any dom inant tren d , i t is towards a rej ection of such simple theories o f re i n ­ forcement as Thorn d ike's l a w o f effect o r Hull's drive-reduction m echan is m s . The n e o - Hullians h ave become i ncre asingly will i n g t o discuss learn i n g in term s o f having emot ional and/or cogn itive com p on en ts, as in the tre atm en ts o f fru s ­ tration a n d i ncen tive mo tivation . O nly t h e s trict Skin n erians s till d iscuss rei n ­ forcemen t a s a p rocess wh ich autom atic ally strengthens tendencies t o res p on d . Even they h ave m oved to the p aradigmatic approach i n w h ic h reinforcement is treate d as no thing more than a proce dure for con troll ing behavi or . I n moving toward incre ased incorporation o f cogn i tive - pred ic tive variables and in see ing re inforcemen t as primarily the result of specified types of proce­ d ures (or p aradigms) , the evolu tion of i n s trum ental/op eran t learn ing theory h as p aralleled tha t o f classical con d itioning theory . A no ther noticeable trend has b een the i ncorporation of m ore b i olo gical vari­ ables, as i n Tim b erlake's and Allison's ( 1 974) a dap tive m odel of ins trum en tal p erforma nc e . Even Skinner, who once a dvoca te d a s trict environm en talist a p ­ proach , h a s d iscussed p arallels b e tween t h e res p onse-selecting aspects o f rei n ­ forcement a n d n a tural selecti on ( evolutionary) variables . Th is h as force d a reex­ a m in a tion of the Skinnerian v i ew of the effects of reinforcemen t as " bl in d " or u naffected by variables w i th i n the organis m . T he m aj or l i n e of evi d ence for the S k in n erian ass u m ption that re inforcem ent is blind to the p urposes of the or­ ganis m is d erived from the s upers titious con d it ion in g p henomenon describ e d i n C h a p ter 4 . Skinner ( 1 948) showed th a t random delivery o f fo o d t o a h u n gry p igeon was sufficien t to produce o p eran t learn ing. S ta ddon an d S i m m elhag (1971) have s ugge s te d tha t b e havi ors wh ic h increase i n freq u ency , rather than b e i n g ran do mly selected by the e ffects of reinforcement, are u su ally related to n atural foo d - ge t ting b e h aviors ; they reflec t the organ ism ' s pre d ic tion that, as time i ncrease s since the last reinforc em ent, reinforcement becomes m ore proba­ ble. These res p on se s are ass umed to o p erate as discri m i n ated o p eran ts and to resem ble the res ponses ac tually m ad e to the term i n al reinforcer . H ence , through s timulus substi tu tion m echan isms, the cue pro p erties o f the resp onses o p erate like Rescorla's p re d ictive C S s . S taddon and S im m elhag make the p o i n t th a t res ponses occurring j us t b e fore the noncontingent reinforcer s hould b e looked a t a s reflec ti ons of the organ is m 's " m o o d " o r s ta te (such as hungry or fearful) , rather th an as b ehaviors . Therefore, the variety of res ponses o b serve d by Skin­ n er using the nonc ontingent reward procedure reflect variou s altern ative behav­ iors associated w i th that particular in ternal s tate ; these responses are assumed to h ave had adap tive value in the evolw.tion of tha t particular orga n is m . Seligman ( 1 975) noted that S taddon and Sim m elh ag rean alyzed Skinner's " s u p ers titious p igeon" d a ta a n d fou n d the beh aviors reported b y Skinn er to b e sim ilar t o n atural " fo o d - ex p ecting b e haviors . " Seligm an s ugge s ts that these responses are conditioned to the schedules u n d er wh ic h fo od is pre sented (m uch like the responses classically condit ioned i n autosh a p in g research to pecking keys when they are p aired w i th foo d ava ilab i l i ty for h u n gry pigeon s ) . A s such, the b ehaviors are cond i t ioned reflexes wh ich resemble n a tu ral u ncon-

266

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d i tioned s pecies - s pecific res ponses to fo od un der hu nger condi tions, not arb i ­ trary beh avi ors " s tamped in" b y happy coinc i d ence with fo od re inforcemen t . I n Sel igman 's view, such " s u pers t i tious" res ponses are in vol u n tary , like a dog l ickin g h is chops b e fore d i n ner. Seligman fu rther suggests that apparen tly " s up erstitious" re s ponses are the s u bj ec t's react ion to i ts helplessn ess ac tu ally to control the delivery of re inforcemen t . Thus Sel igman explains " s u p erstitio u s " behavior in term s o f h is mo del o f " learned helplessness" (revi ewed i n C hapter 8) . Staddon and S i m melhag ( 1971) have also inves tigated the behaviors occ u r­ ring j u st after a re inforcer has b een delivere d and consumed . These i n teri m activi ties, p resu med t o re flect the orga nism's pred iction t h a t re inforcemen t i s n o t i m m e d iately forthco ming, are thus relate d to o ther kinds of motivational s tates . Put simply, the organism realizes th a t it does not have to get ready for a food re inforcemen t, so i t attends to other b u sin ess . Dunham's ( 1971 , 1972) o b­ serva tions of increased drinking beh avi ors follo wing s hock in gerbils and ra ts could also be in terpreted as the animal's prediction th a t the postshock p eriod is a safe time in which to e m i t non -shock -rel a ted instrum en tal behaviors . These in terim ac tivi t ies resemble the appetitive behaviors (those ulti ma tely leading to consuma tory resp onses) described by the e thologists ( to be reviewed in C hap ter 12) . Th us, Staddon and S i m melh ag have begun the proc ess of d iscoverin g com­ mon p rinciples u n d erlying both ins tinct- biased and instrumen tal/classical con­ d i t ioning phenomena . This allows the m to look a t rei n forcement and learn i n g mech a n isms in term s of the well-researched bi ological concepts o f sel ection a n d variation . This may provi de a basis for a fin al resolution o f the ins tinct vers u s l earning ( n a tu re/n u rture) iss u e and a gen eral theory o f be havior. To conclude, Staddon and S i n1 melh ag h a ve p roposed a reevaluation o f an o perant p heno n1enon whic h incorpora tes both cogn itive ( predictive) and biological- evol utionary varia bles . As such, the ir work sugges ts a d irection for relating o perant pheno m enon with cogn itive princ i ples ( to be covere d in C hap­ ter 11) and b i olo gical principles (to be covere d i n C hapter 12) . Before we exam­ ine these approaches, however, l et u s look a t the i n1 p ressive ra nge of appl ica­ tions wh ich have been the by- product of the o pera n t a pproach to behavi or in i ts presen t s tate . ---

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K e y Terms ad apt ive m odel

fractional an tici pa tory frustra tion ( r F = S F)

pa in-aggression response

i m aginal sys tem

partial rei nforcemen t e f­ fect (PRE)

i ncent ive motivation

participant m od e l i n g

i n tertrial re in forcement

peak s h i ft

modeling

posi tive co ntrast P rem ack princ i p l e

error l ess l earn i ng ( fa d i ng)

multiple- response b asel i n e p roce dure

forced p ractice

n egative contrast

b e ha vi oral contra st b e havior m o d i fication conditioned facil itation contrast emp irical l aw of e ffect

p repotent theory o f rein­ forcem en t

Reinfo re em en t- R elated Lea rning

progressive m o deling

sequential hypothesis

t i m e out

resistance to punishmen t

S id m a n avo i d a nce

verba l system

response depriva tion m odel

signaled avo i d a nce

vicarious ext i nction

social learn i n g the ory

vicarious learn i n g

revers ibility (transitivity) o f rei n forcement

superordinate s t i m ulus

self- m odeling

symb olic modeling

267

Annotated Bibliography Three representative readings related to neo- Hullian approaches to in s trumen ­ t al learn ing are : ( 1 ) A . Amsel, "The role o f fru s tra tive nonreward i n noncon tin u ­ o u s reward situations" (Psychological Bulletin , 1 958, 55 , 1 02-1 1 8 ; (2) E . ] . Capaldi, " M e mory and learn in g : A seq u ential viewp oint, " in W. K . Hon ig and P. H . James (Eds . ) , A nimal memory (New York : Academ ic Press, 1971 ) ; and (3) F. A. Logan , Fundamentals of learning and motivation (Dubuque, I owa : William C . Brown , 1 970) . Neo - S ki n nerian ap proache s to posit ive re inforcem en t a n d n ew principles are well repre sen ted by : (1) two articles b y D . Prem ack, "Toward empirical b eh avioral laws : I . Positive reinforcem en t" Psychological Review, 1 95 9 , 66 , 219233 , and " Reversib i li ty of the reinforcement relation , " S cience, 1 962 , 136 , 255257; (2) G . S . Reynolds, A p rimer of operant cond itionin g : Revised (Glenv i ew, I ll . : Scott Foresma n , 1 9 75 ) ; and (3) two a rticles b y H . S . Terrace (Journal of the Ex­ perimental Analysis of Behavior, 1 963 , 6, 1 -27 and 223-232) . Key readi n gs in the area of aversive contro l of behav ior s ho uld i nclude: (1) N . H . Azrin and W. C . Holtz, " P un ishment, " i n W. K . Honig (Ed . ) , Operant behavior: A reas of resea rch and application ( N ew York : Ap pleton -Cen tu ry-Crofts, 1966) ; (2) P. ] . Dunham , " Pu n ish m en t : M ethod and theory" (Psychological Review, 1971 , 78 , 58-70) ; (3) I . L ovaas, " After you h i t a ch ild , you can't j us t get up an d leave h im ; You are hooked to t h at kid (A conversation with P. C hance)" (Psychology Today, January 1 974 , 7 , 76-84) ; (4) M . E . P. Seligm a n and J . C . J ohnston , " A cogn itive t heory of avoi da nce learn ing, " i n F. J . McG u i gan and D . B . Lumsden (Eds . ) , Contemporary approaches to condition ing and learning (Washingto n , D . C . : V. H . Winston & Sons, 1973 ) ; (5) M . S i dman, "Norm a l sources of p atholo gical b ehav i or" (S cience, 1 960 , 132 , 6 1-68 ) ; and (6) R . L . Solomon, " P unishment" (American Psychologist, 1 964 , 1 9 , 239-253) . C ogni tive behav iorism and modeling is presented i n A . Band ura, Social learning theory (Englewood Cliffs, N . J . : Prentice-Hall , 1977) . fur t hose wishing to read two provocative articles evaluating older views of instrumental learning, I would recommend J . E . Staddon and V. L. S i mmelh ag , "The ' su p erstition' experiment : A reexam ination of i t s i m p lications for the p ri n­ ciples of adap tive b ehavi or" (Psychological Revie w , 1971 , 78, 3-43 and W. Ti m ­ berlake a n d J . Allison , "Response deprivation : An emp irical approach to in­ s trumental performance" (Psychological Revie w , 1 974, 8 1 , 1 46-1 64) .

Ap p li cati ons of O p erant L earni ng P ri nci p l es to the R eal Worl d

When most people th ink o f behavioral modifica tion , they think first o f phobia rem oval through systematic desensitization or o f aversive con d i t ion ing o f the typ e pop ularized in the film A Clock1vork O range , w h ich we d escribed in C h ap­ ter 6. These types o f b ehavi oral m odifica ti on , the first to be h i ghly develo p e d , continue to b e important in help i n g p eople overcome problem s caused by inap­ propriate fears or motiva ti ons. M ore l ives, however, are currently being touched b y a recen tly d eveloped form of b eh a vi oral modi ficat ion th at is o ften lab eled contingency management. Con t in gency m anagement is the art and sci ence of controlling the rules rela ting a p erson' s beh avi or to the consequ ences of that behavior (re in forcements) . Altho ugh ap plications o f classical condi t ion ing for the most part have b een confin e d to cl i n ical settings in wh ich a therapist or m e d ical do ctor works with a single clien t, re i n forcemen t- based con d i tioning principles have b een fo und u se­ ful in an extrem ely wide ra nge o f se ttings . These ra nge fro m asth ma rel ief in cl i n ics to zoo p rogra m s for increasing an imals' d a ily activi ty levels . The princi­ ples have b een u sed in one-to-one counseling, in grou p settin gs, and on whole wards or natural popula tions o f people . They have b een applied by the usual pro fe ssionals, such as counselors, teachers, and med ical d octors, by parapro fes ­ sionals, and by ind ivi d uals on themselves an d/or the ir sign i fica nt others . Be­ cause o f the extreme d iversity o f environm ents and target popula tions affected by application o f re inforcement principles o f the type firs t systematized by Sk in ner, only a few gen eral guidelines can b e give n . Th is cha pter will begin by presenting these general rules for ap plication of Skinnerian con d ition ing theory , a fter which spec i fic types o f ap pl ications and s pecialized rules will b e given .

G eneral Principles of Contingency Management There are th ree s tages to all well- done p rograms of con t ingency management, and we w ill expl ore the vario us events and procedure s applied to each s ta ge . The th ree stages are : ( 1 ) sp ecification, (2) observation, and (3) consequation. Malo tt ( 1 974) calls this the "SOC it to 'em ! " model of con tingency manage m en t .

S pec ifi cn t i o n Be fore d esign ing a pro gra m for contin gency management, you must first s pecify : ( 1 ) wh ich be havi ors you wish to work with , (2) what rein forcers yo u

Applica tions of Operan t Prin cip les

2 69

w ill u se , and (3) how the reinforcers will be rel ated to the occ urrence o f the b eh aviors ( the contingenc ies) . The first step in b egin n in g the process o f c on t in gency m an agemen t is to decide what b e ha vi oral changes you wish to see occur and with w ho m . P ro ­ gra m s try t o c h an ge visible behavi ors because changes inside of peoples' heads, such a s " better life adj us tm en t , " canno t be o bserved . Therefore, d i fferen t o bser­ vers would not b e able to agree w hen your goal had b een re ache d . To a i d i n objectivity, i t i s a good i d e a to l i s t a s e t of o b servation p rocedure s o r o peration s that any trained o bserver could follow and tell when you r t arget b eh avior h ad occurred or not occurred . This is calle d t he operational definition o f your depen­ dent variable (the t arget behavior) . Spec ifying the operati o n ally defined, desired behavioral o utcomes o f your p rogram o f con t in gency m an agement is c alled stating your behavioral obj ectives. An example of a behavi oral o bj ective m ig h t b e reducing a c h ild's rate o f talking b a c k t o the teacher fro m o ver twen ty times p er d ay to u n d er two times per day. The rules for d efin i n g " talking b ack" s hould be so specific th a t o ther o b servers wo uld agree w i th you b o th on when such un d esired behav i or had occurred a n d when you r goal had b een reached . Just bec au se the goals , or behavi oral o bj ec tives, o f cont in gency managemen t pro­ gram s should n ever be stated in terms of t h in gs happen i n g with in the " target p erson 's"* head does not m ean that c on tingency m an agers do not feel that things like " be tter l ife adj u stment" are u n i m p ortant ; i t only means that behav­ i or alone can b e measure d rel iably ( as in h avi n g several o bservers agree ) , and that there fore t he contingency m an ager must c arefully select t arget behaviors w h ich he or s he assumes to be rela ted to the inner experiences of the clien t or t arget p erson . There are two o ther i m portan t aspects o f selecting the beh aviors to b e m o d ­ ified . Firs t , they s hould be within the t arget p erson' s capab i litie s . U nrealistic selection leads to fru stration an d extinction on the p arts o f b o th modifiers a n d persons to be m o di fied . Malott ( 1974) suggests a " th in k s m all" rule . By h avi n g l i m ited o bj ec ti ves, the probabilities of accomplishing b i g are increa sed . Once one goal is reached , it is always possible to set up a secon d and m ore demanding goal . Deman d in g too much , too e arly, strains your schedule control . Sec on d , y o u m u s t select a n app ro priate begi n n i n g poin t for change. N ormally, the m o s t e fficien t s trategy is to "begin where t h e behavior o f the p erson t o b e m o d i fied i s a t " and re in force small chan ges in the d esire d d irection un til fin ally your behav­ i oral o bj ective is reached . This is, of course, the same a s saying t h at t he d e sired t arge t behaviors have been fully shape d . T he selection o f reinforcers m u s t also b e carefully spec ified . G ood reinfor­ cers m u s t be available to the mod ifier, m u s t be reason able in cost b oth in term s o f mon ey an d of modifier's time, a n d m u s t b e e asily deliverabl e . A n d , of course , they m u s t b e re in forcers in Skinner's terms . That is, they m u s t b e wan ted * T h e term " target person " is u se d to refer to the p erson w hose b e havior i s to b e m o d i fie d . The u n desirable e m o t ion al connota t i on s of the word "target" are regrettable , b u t m o st a l tern at iv e terms, such a s "client" or " s u b j e ct , " do not a p ply in a ll cases, an d precise and non e m o t i on a lly loa d e d term s, s u c h as " person w hose behavior i s t o b e mod i fi e d , " are u n w i e l d y an d bori n g t o re a d a n d write.

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A l odern Con ten ders

eno ugh by the targe t person to have h i m or her chan ge beh avi ors to get the reinforcers . What see m s to b e a re inforcer to you may not be a re inforcer to your targe t person . Pra ise from a te acher to a child who d islikes that te acher may actu ally b e an aversi ve event ra ther than a rein forcer! A good way to determ i n e what t o u se as re inforcers i s t o lis t all the re i n forcers you m i ght u se an d then have the targe t person specify which of these he or s he wo uld work for . A com m on m isconce ption about rei n forcers is t h a t they m u s t b e physical, s uch as candy or money. Many persons obj ect to s uch concrete re inforcers b o th on gro unds o f too th decay and of m oral decay ( the m o d i fier is " b ri b ing" the targe t person) . Leaving aside the iss u e o f whe ther m an y s uch cri tics would continue working on the ir o wn j ob s wi tho u t concre te re inforcers, behaviors m ay b e as u seful as concre te re inforcers i n shaping desire d behavi ors . We explore d the u se o f h igh - freq u ency beh avi ors as re inforcers in C h a p ter 9 i n the section covering the Pre m ack principle . Ro ughly stated, this principle s uggests telling the targe t p erson , " I f yo u do this low-frequ ency behavi or th a t you do no t see m to l ike to do, then ( the con tingency) I will let yo u do a h i gh - freq u ency b e ­ h avior t h a t y o u seem t o w a n t t o do a lo t . " O r , m ore concre tely : "If y o u e a t spi nach , then you c a n emit som e ice-cream -eating behavi ors . " O f course, the would-be modifier m ust make s ure th a t he can con trol when the targe t person will be able to e m i t the re inforcer re sponse s . A general ru le for classroom appli­ , cations is to u se h ighly liked beh avi ors which req u i re some physical s u p plies or accessories . Thus, not fighting m i gh t be re in forced by b e ing allowed to play records th at the teacher can lock u p un til the behavioral o bj ectives are re ached . Beh avi ors th a t req u ire the coopera tion of the mod ifi er may also b e u sed as re inforcers . The au thor once he ard a talk in vvh ic h the s p eaker related that being given access to a Fre u dian psychoanalyst was the reward for the m ental patient's em itting desired be havi ors i n a hos p i tal behavioral modifica tion pro gram . A t­ ten ti on from a te acher, the teacher's reading o f an exc iting s tory , or conti ngent pra ise m i gh t equ ally be u sed . As a gen eral rule , nonp h ysical re inforcers are most u se fu l with target p er­ sons who are rel atively b right, n1 atu re , and free from severe b e h avior problem s . When these con d i tions are no t met, som e concrete re inforcers n1 ust b e u se d . The m ore severe the probl e n1s, the more rel iance m ust b e p laced on ph ysical rewards . Even when p h ysical re inforcers n1 ust be use d , i t is often d i fficu lt to del iver them in1 n1 e d iately after the desired beh avior occ u rs (or after a specified in terval elapses) w i tho ut having the und esired behavior occu r in betw een . In s uch cases, con d i t i oned or secon dary re inforcers n1 ay be use d . These n1 ay only be a s i gnal to the targe t person th a t he h as met the be havi oral cri teria* ; they n1ay be marks on * W hen an i m al tra i n ers arc faced w i th the problem of m a i n ta i n i n g a long seq ue nce of behav i or wh ich takes the a n i m al o u t of range o f the tra i n er and p r i ma ry re i n forcers (such as fish for k i ller w h a l es) , they use

a

secon d a ry re i n forcer called a " b ri d g i n g ga p . " Th i s i s ei ther a h a n d or body v i s u a l

sig n a l o r ,1 n au d i tory c u e from a cl icker or w h i s t le w h ich has beco m e a ssociated w i t h the p r i m ary re i n forcer th rough a classical con d i t ion i ng proced u re. T h e s i g n a l is g i ven whenever the a n i m a l s u ccessfu l ly co m p letes a port ion of t h e seq uence .

App lica tions of O p era n t Prin ciples

271

a blackbo ard or i n a no tebook, or they m ay b e p h ysical " token s , " such a s poker c h ip s . For severely re tarded or d is tu rbed target persons, phys ical tokens are u s ually necessary , and they s ho u ld be large enough to d iscourage being e aten . Large size m ay also help red uce the ft pro blems i n ward se ttings . Tokens m ust b e gu arded as care fully as pri mary re inforcers, and, i n the case of blackboard or notebook marks, the target persons m u s t be prevented fro m cheating by erasing or adding m arks . A person trying to shape h is own beh avior m ay use a golf coun ter to note when he re aches behavi oral goals, such as not s m o k in g during a 1 5 - m i n u te in terval . Each p re ss of the b u t ton on the coun ter is a second ary re inforce ment i f the person later rewards him self for s p ec ified total coun ts . I n general , tokens o r other typ es of con d i tion e d re inforcers are m ore conven i ent than prim ary re inforcers and help to preven t s a t iation , w h ic h m ight occur through delivery o f too many primary re inforcers . This p henomenon of m a i n ­ tain i n g a behavi oral chain through secon d ary re inforcement and o btaining superior resis tance to extinction and sati ation i n volves the p artial re i n forcemen t e ffect . This i s the same e ffect that m a intains re s pond ing on long ratio an d i n ter­ val sche d ules . As with "lean" schedules of re inforcement, i t is o ften n ecessary to begin with continuous re inforcement u sing primary re inforcers, gradu ally shap­ i n g acce ptance o f more and more sec ondary re inforcers to each p ri m ary re i n ­ forcer . Fai lure t o shape the re sp onse t o the leaner sche dule gradually often results in straining the sche d ule, or u n pl anned extinction o f com peting response s . A fin al note o n the specification o f re inforcers . Even t hough m an y re infor­ cers m ay be e ffective in m aintain in g h igh l eve ls of desire d behavi ors, the re i n ­ forcers them selve s m ay h ave undesirable side e ffect s . H arlow ( 1953) found that rhesus monkeys given foo d rewards for solvi n g m echan ical puzzles s ub se ­ q u en tly solved fewer such p uzzles when the fo od w a s d iscontinued than mon ­ keys given t he puzzles wi thout fo od rewards . This ra ises the dan ger that so m e prim ary re i n forcers m ay i n t erfere w i th the operat ions of less powerful re infor­ cers (such as a love of le arn i n g) , which m ay re flect a behavioral con tras t e ffect (see C h apter 9) . A second possible und esirable side e ffect o f potent re i nforcers is that these re i n forcers m ay them selve s evoke und esirable re sponses or h ave u n ­ desirable conse q u ences . For example, the au thor h as fo u n d that while j uven ile d e l in q uents could be i n duced to im prove the ir ro om cleanup behaviors m ark­ edly by u se of cigarette re inforce me nts, this led to a s harp rise in the ir rate of smok ing, raising the specter that the be h avior modifi ers will further contri b ute to their heal th p ro bl em s . The fin al go al i n the specifica tion s tage o f a contin gency m an age men t pro­ gram is speci fica tion o f the relationsh i p , or contin gency, be tween t he d esire d b e h avi oral o u tcomes and the re i n forcers . S hould you begin with a constant ratio o f re i n forcers to b e h aviors, or should you try to shape tol erance for leaner schedules as your program pro gresses ? S hould you use the same re i n forcers througho ut, or s ho uld you try to pro gress from prim ary rei nforcers, such as fo o d o r toys, an d powerful gen eral ized second ary re inforcers, such as m oney, first to a token s ystem , and fin ally to soc ial re inforcers such as praise? Is your goal to

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i\ l odenz Con tenders

ma i n ta in the desire d behaviors indefin itely through your schedule o f re i n ­ forcemen t; or, after y o u r behavioral obj ectives have b een o b t a i n e d , do y o u hope gradually to term in a te your reinforcers? In gen eral, the rule s pec ify i n g the relationsh ip o f b e h avi or to re inforcemen t s hould b e very cle arly comm u n icated t o your targe t p ersons . Because changes in your rules m ake the con t in gency unclear, they should be avoided i n your initial program . Seligman ( 1 973) has presented d a ta sugges tin g th c.t failure to p erc e ive the relation sh ip b e tween behaviors an d o u tcomes may res ult in the phenomen a o f learn e d helplessness, where the p erson ceases t o try t o gain re inforcements . With brigh ter or more m a tu re targe t persons, a token or o ther type of second ary reinforcemen t sys tem can be ins t i tu ted from the beginn in g . The au thor has used such a system with college stu den ts for years, w i th good results . Attempts to mod ify i t in m idco urse , however, lead to confu sion and often resentmen t . Therefore , sh aping t o leaner sche dules, transferring con trol from concre te re i n ­ forcers t o soci al reinforcers, a n d o ther attempts t o re duce the response cost o f a contin gency managemen t sys tem to the modifi er should only be made after the original b eh avioral obj ectives have been m e t . S igns of resentm en t or break­ down s in sche dule control should be carefully watche d for, and the m o d i fier must b e prepared to ins titu te changes very gradu ally to preven t " s train . " A b ­ ru pt extinction procedures are to be avo id e d , as they m a y result in i ncreases i n the behaviors s pecified as und esirable as well as incre ased varia b i l i ty in w h a t may b e i neffec tual coping responses . The s uccess o f attem pts to chan ge the origin ally specified contin genc ies is related to the level of your targe t p ersons . Brighter an d/or better- adj usted per­ sons have more i n trin sic reward systems and m ore altern ate sources of reward, and m ay tol erate changes better . Ward populations and severely re tarded per­ sons m ay req u ire planned con ti ngency m an a gement for m uch of the ir i n ­ stitutionalized lives . In a sense, contingency management pro gram s m a y simply help such persons to be able to see the rela tionships b e tween the ir actions and environ m ental consequenc es for the first time . Because the contingenc ies are s p ecified in a simpl ified and exaggerated way, in d eli bera te programs compared to norm al social environments, h ighly re tard e d or d is turbed ind iv id uals may com prehend for the firs t tin1 e in the ir lives th a t such rela tions hips e x is t . For s uch persons, the con tingency manager's e n1 phasis s ho u ld be on immediacy and sim plic i ty . For " norn1 al" popula tions, considera tions of flexibility and re d uction o f the efforts req u ired by the managers may be most importa n t . Even wi th soun d - m i nded college students , ho wever, the au thor has found i t necessary to be h ighly explic i t abo u t what he expec ts for so n1 any p o i n ts of cre d i t to wards a specifi ed cou rse grad e . Successfu l con ti ngency manage ment d epen ds upon clear communica tions ! There is one fin al aspect o f specifying the contingencies in a particular situa tion : Should only one simple contin gency b e use d , or are multiple con­ ti ngencies d esirable? O ften a systen1 based only upon posi tive reinforcem ent breaks down because of con1 peting res ponses . I f one ch ild gets m ore re inforce­ ment fro m the attention of h is or her p eers th an you can deliver for des ira ble behavior, then not only will you fail to con trol the behavi or o f th a t child, b u t

App lica tions of O p era n t P rin cip les

2 73

schedules applied to o ther children w ill b e disru p te d . In such cases, aversive controls m u s t b e added to your sys tem . The m ildest type of these is simply to i gnore the und esirable beh avi or in hopes that it will extingu is h . If this fails, rem oval from the situation where posi ti ve reinforcers may be earned ( ti m e - o u t proce dures) may be tried . If t h is i s no t sufficient, then punishmen t conti ngen ­ cies m ay h ave to b e added to the positive re inforcement c ontingenci es . Lovaas (C hance and L ovaas, 1974) h as been successful i n u si n g severe physical punish­ ment with au tistic children , b u t i n general p hysical p u n ishment s hould be avo i de d . This is because i t may be d i fficult to use such p u n is hers at a strength w h ich w ill result in lasting suppression of the u n d esired b ehavi ors without producing severe side effects in the p erson p u n is he d and wi tho u t exposing you to p oten tial legal and ethical complications . E ffective use of p u n ishment, in general, and especially physical pun ishment, is a complicated task (recall the discussion of pu n ishmen t in the preceding chapter) , and severe p hysical pun­ ish m ent is u sually forb i dden in m o s t i n s ti tutional settings, such as schools . Safer and legal punis h m en t proc e dures are a va ilabl e , howe ver, that are appl icable in institutional se ttin gs for those situ ations in w h ich aversive c on trol is appropriate . Skinner u se s the term "punishment" to d escribe b o th contingen t delivery of aversive conseq u ences and contingen t nondelivery of posi tive re i n ­ forcers . Taking away access to d esired activi ties or other p osi tive reinforcers is generally b oth e ffective and less likely to cause unwanted side e ffects than phys­ ical punishment. Bartlett and Swe nson ( 1 975) , for example, were successful in u si n g late access to recess to con trol d isruptive behavi ors i n gro ups of p roblem sixth gra d ers . B artle tt's technique was to m ake u n d esirable res ponses cost p o si ­ t ive reinforcers, an e ffective type of punishment proce dure because i t can easily b e con trolled b y the modifier. Rememb er that most organ isms res p on d to p u n ­ is h m en t w i t h atte m p ts a t avo i d ance o r escape ; the s u p pression o f und esired b e havior will not occur u n til s uch a ttempts cease . The would-be u ser o f p u n ­ is h m en t m u s t also b e al ert t o the p ossib ility t h a t desirable behaviors m ight also b e sup presse d and that pun is h men t m ay trigger em otional problems in so m e p erson s . Even with college studen ts, som e types o f aversive control may b e n ee de d . The deadlines for handing in assign men ts, if enforce d , p u n is h " dawdling and d elayi n g . " DuNann and F ern ald ( 1976) reporte d using a "dooms day" con­ tingency: I f m i n i mal assign ments were not completed b y a s pecifie d date, the slow-s tartin g studen ts could be forced to dro p the contin gency- m an age ment­ based course . I n practice , som e aversive contin gencies are usu ally n ecess ary whenever the modifier is u n d er time pressures . These s hould be m i n i m ized and u se d pri m arily to preven t competing behavi ors (such as c h il dren w ho d isru p t cla sses or college stu dents w h o delay completing assign m ents) from in terferi n g with t he effects o f y o u r primary p o si tive rein forcem en t con ti n gencies . As a rule o f thu m b , bri gh ter target p ersons m ay b e expose d to as many concurrent contingencies as you and they can kee p s traigh t , as long as each contin gency serve s som e val i d p u rpose i n help i n g you to re ach your behavioral o bj ective s . Wi th d is turb e d or slower targe t p ersons , one posi tive contin gency an d one seldo m - u sed p u n is h m en t con tin gency are usually sufficien t .

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J\ I odenz Co11 te11 dcrs

To design an effective cont i ngency management plan, first define target be­ haviors (behavioral objectives) operationally. Note current behavior and how t o go from t hat behavior t o the target behavior without " st raining" your con­ trol. Next , specify reinforcers (pri mary, secondary, and aversive) and their contingency relationships to behaviors. When aversive conseq uences are necessary, emphasize t he rem oval of positive reinforcers.

0 bserva ti o n

I t is a gen eral ru le i n con d itioning that the closer i n time t h e rei n forcing event (the US, in classical conditioning) follows the d es ired res p onse (the CS, in classical con d i ti oning) , the m ore effective the con d i t ion ing will b e . In shaping operan t b eh avior, you m u s t catch a m ovement i n your desired d irection i m m e ­ d i ately . Otherwise , y o u will b e reinforc ing a la ter behavior w h ich m a y not help you in compl eting the shap ing proc ess . Therefore, you m ust carefully ob serve in order to d eliver reinforcers at the mom ent when they will reinforce b eh aviors related to your behavioral o bj ec tives . To do this, y o u m u st h ave cl e arly s p ecified what types of responses you consider examples of d es ired behaviors . T h is s p ecific ation of the rules, or o p erations, for m eas uring the occurrence of the targe t behavior (your depen d en t variable) is, of course , the o p erational defin i­ tion of what is considere d a re inforceable response . If you fa il to note ins tances , of d esirable behavi ors, s uch behaviors may ex ti ngu is h . In a si m ilar vein, letting severely d isrup tive b ehaviors pass without p u n ishm ent a fter yo u have estab­ lis hed a pun is hment contingency reinforces " test ing the l i m i ts . " M ost success ful programs work ing wi th s everely retard ed or d isturbed in divid uals have s tressed extre m ely close indi vidual o bserva tion . While observing every d esired res p onse is the way to reach your behavioral obj ec tives most q u ickly, such an ap proach is i m prac tical in environ m ents s uch as cl assrooms where you are dealing wi th several target person s sim ultaneously. In classrooms, it is i m possi ble to watch everyone every n1 i n u t e . Several partial so lutions have b een o ffered for this problem . One answer is to u se time sam­ pling. With this approach, your observing b ehavior is e i ther on a fixe d or variable interva l sche d ule . When the plann ed observing tin1 e approaches, you look aro u n d the roo m a n d q u ic kly note what everyone is d o i n g . If you re mem b ered to " th i n k s mall" and do not have too n1 any or too con1 pl icated ru les for d eter­ m in ing d esirable behaviors, you sho uld be able to note those ind ivi d uals doin g d esira ble , u n d esirable, and " o ther" behav i ors . I t is very helpful to have a shee t o f pa per in front o f you to allow you q u ickly to c heck the ap propriate categories of behaviors for each ta rge t person by t i 1n e in tervals ( see Figure 1 0 . 1 for an exam ple of a be havi or record ing form) . I f yo u h a ve access to a ti m ing device or can glance a t a wall clock or wr istwatch at re gular intervals , the fi xed interv al " observation win dow" tec h­ n iq u e may be most sa tisfactory . If you tend to have d i fficulty rem e m bering to check the tin1 e or if you r target p ersons learn about your fixed interval and d o m os t of the i r good be havior i n the t i n1 e j u st b efore y o u d o your recording ( the fixed in terval scallop) , then a m o d i fied in terval sche d ule may b e a practical al tern a tive . I n this case, you vary the times when you will observe target behav-

App lica tions of Opera n t Prin cip les

D Sa l l y D

u

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des i r a b l e

Sam N

D

u

U

=

u nd e s i r a b l e

D

u

=

neutral

Skinner

Sa ra N

N

2 75

N

D

u

N

9:00 A.M. 9: 1 5 A.M. 9:30 A.M. Tota l s :

Fig u re 1 0 . 1 people . 0

=

A sa mple da ta sheet for recording tim e-sampled inform a tion fro m a g ro up of desira b le , U u n desira b le , N n eu tra l . =

=

iors aro u n d a preselected m ean t i m e value such as 10 m in u tes . C hoosing the i ntervals in adva nce and record i n g the m on a ca sse tte tape mach in e to be play e d i n the classroom is a g o o d w a y to do t h is . A m ore detailed description of this tim i n g tape tech n i q u e is given i n the appendix to this chap ter . Ti m i ng tapes s hould only b e used i n si tu ations i n wh ich the m odifi er is able to hear the tap e d c u e s o f when to o b serve w i thout allowing the sound o f those record e d c u e s to d isrupt t he b e haviors of the target persons . When the tap e d time sign al techn i q u e is im practical or impossible, you may genera te a q uasivariable i nterval schedule by attempting to check behaviors at re gu lar i ntervals . If you glance a t the clock and fin d you are a couple of m in u tes early, check o ff b e havi ors anyway . If you are a couple of minu tes late , so m uch the b etter . In a sense , your o wn i nconsistency can generate a de sirable de gree of ra n d o m n ess in a way wh ic h will not disru p t your m o d ifyi ng envi ronmen t . A las t maj or considera tion with time-s amplin g techniques i s dec iding o n the freq u ency o f the "ob servation win do ws" on the target person s' behavi ors . As a rule, short i ntervals give m ore accura te i n form a tion in less time but are m ore of a d is rupting factor for y o u . If your m a i n j o b is to o b serve behavior, then the response cost of s hort i n tervals will no t be too aversive . If yo u are also req u ired to teach or p erform o ther fu ncti ons, however, longer interva ls are m ore practical . S hort intervals are m ore tolerable in s hort-term s tu dies or modification progra m s, while con ti n u i n g programs reduce the n ee d for frequen t ob serva tio n . Longer i ntervals be tween o b servat ions are compatible w i th program s o f long d ura tion, both b ecause they take less o f your time (re d ucing the probabili ty of havi n g your own sche dules strained) and b ecause s u fficient data can be ga thered over a long time p eriod from widely spaced o bserva tion s . A no ther techn i q u e for o b serving behavior o f p ersons i n groups i s the focal individual tech n i q u e . In this techn i q u e , y o u randomly order the n am e s of the p ersons to be o b served . Aga i n , prin ting each name on a sl ip of pap er and p u tting the papers i n a con tainer is a simple ra ndom ization procedure . Do not re place names after they are drawn from the c ontainer . Write the names i n order on a p iece of p ap er and o b serve the targe t p ersons i n that order. With this techn i q u e , only one p erson is o b serve d a t a given t i m e . I t is best to re draw the names for each day's ob serva tions to control for d i fferences due to the time a t w h ich each person i s ob serve d . I f t h is i s too m uch work, e i ther gen erate a

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A l oden1 Co11 te11 dcrs

number o f l ists a t one time through s uccessive draw ings or rotate the names through the list so that the p erson o b served first on one day is o b served las t on the next . The focal i n d ivid ual tech nique is preferable to the time-s a m pling technique when the behavi oral obj ectives for the differen t target persons are different or where you are simultan eously sampling se veral behaviors and re­ cord ing each of them . However your observa tions are ga there d , your n ex t step is using them prop erly . W hen work ing with ind ivi d u als who h ave s hort attention s pan s, you would pro bably have to follow u p each ob serva tion of a desire d beh avior w i th e ither a primary (unl earn ed) or a second ary (con d i tioned) reinforcer . With indi­ viduals who have in termedi a te a tten tion spans, such as norm al fifth-grade school children , it may b e eno ugh o f a secon d ary re inforcer for the child to see you make a plus m ark by his n am e . Wi th older norm al children and norm al adults who may be trying to change behaviors, the da ily record may serve as a s ufficient secondary reinforcer ( assu m in g it s hows progress) to mai ntain m o tiva­ tion . A record of behavior over several days is called a chart, and filling out such a c hart is called charting. For many adults, kee p i n g a record of their progress towards a goal , such as losin g weight, may by i tself allow them to emit those b ehaviors (such as avo iding third helpings of food) comp ati ble with mee ting their b e havi oral o bj ectives . Since charting u sed by i tsel f avoids the implications of bribery in heren t in turn ing in secon d ary reinforcers for primary re inforcers, it would seem the program of cho ice for mature, well - adj u s ted indivi d uals . Backing u p a program of chartin g behavior with o ther reinforcers, ho wever, en h ances the effects of such a sys tem . C harting can also b e done by target person s themselves , and will often have desirable motivational effects . The au­ thor provi des charts for s tu dents to record their weekly accum ulations o f points and to mark c u mulative p o i n t to tals by weeks . U n fortu n a tely, many students do not fill out the ir charts, and i t is o ften j u st these stu d ents who are doing the wors t in class . The au thor h as fo und th at backing up " chart- fill ing-o u t" be hav­ i ors on the part of stu d en ts with point contingencies increases both the p ercen t­ age of students filling in the ch arts correctly and those doing rn ore and be tter­ quality work (Swenson , 1975) . A san1 ple of this chart can be seen as Fi gure 1 0 . 2 . I t is filled in with the points that might b e earned by a n "A" stu den t . One advan tage o f charting for the n1odifier i s tha t i t avo i ds the problem o f allowing your moods to color your evaluations of how well your mod ificati on progran1 may be working. If you are feeling de presse d , yo u may feel your program is a fa ilure ; on an " u p" day, in contras t, you n1 ay feel your program is fan tas tic . Both of these j u dgn1 ents n1 ay be biased and in accurate . Accura te o b ­ serva tion a n d record ing (chartin g) are both essential in gre di ents in the process of evaluating your progress toward s n1 ee ting yo u r beh avi oral o bj ectives . Sub­ j ective i m pression s are more often inaccurate than no t ! O bj ective data may also help the te acher or cou nselor to den1 onstra te tha t they are m eeting the ir behavior o bj ectives when they mee t wi th adn1 i n is tra tors eval uating the ir p erformance as part of an accountability process . Since subj ective factors play such a large role in evalua ting, for ins tance, how well a beh avi oral mod ification proj ect is doing, the o bj ec tive record of a ch art is very helpful .

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Applica tio1ls of Opera n t P rin cip les

S E L F- C H A RTI N G FO R M

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(By Wee ks)

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Q u i zzes

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Most o f t he d iscussion to this p o i n t has b een o n o bservatio n for t he sake of accurate notati on of occasions for conse q u a ti on . But w h at about the iss ue of program evaluation and its relations hip to obj ective d a ta? Well - don e charts of fre qu encies o f target behavior s are useful, but they s u ffer fro m one serious flaw i f they only chart behavior s fro m the begi n n ing of the i m plem entat ion of a program to its (hopefull y s ucce ssful) term ination . This flaw is rel ated to time­ correlated changes i n behavior s, w h ic h m ay b e c onfused w i t h the e ffects of a program . Just getting the sort of attention p rovided by a focu sed program m ay re i n force desired b ehaviors . Many children fin d p articipati on in token economy program s a typ e of game an d respond w ith i ncreased i n terest i n school . Behav­ i ors change for re ason s not readily ap p aren t ; if s uc h changes occur d u ring y o ur progr am an d are positive , who could blame y o u for taking cre d i t for the changes? O n e way to evalu a te the precise e ffects of your i n tervention s is to use the multi ple baseline procedu re . You b egin by collectin g data on the freq u enc ies w i th wh ic h t he targe t b e h aviors occur before you s tart your program of con ­ t i ngency man age m en t . This allows your subj ects to get u sed to the o bservatio n proce dures w h ic h may be t he m selve s change be haviors. It is a time to p ractice

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ob serv ing wi tho u t the n ecessity o f also having to prov i d e re i n forcers and sharpen your original specifications . This perio d of time, calle d baseline 1 , serv e s as a con trol for the effects of the cont ingency management progra m . Then you i n i tiate your in terven tion ("on-contin gency") time p eri o d , continue to record data until you reach the b e havioral obj ectives or clearly h ave failed, and then h al t y our con seq uation wh ile contin u ing to record behavi oral freq u enc ies (baseline 2) . The secon d baseline allows evalu a ti on o f long- term effects inde­ p en d en t o f your admin is tra tion of reinforcers . Multiple baseline proce dure s altern ate baseline periods w i th "on -con t in genc y" time periods several times to d e term i n e re inforcement con trol . Because it is d ifficult to maintain the desired degree of accu racy i n o b serva ­ tions o ver long time peri ods, mechanical methods of observing behav i or have been develo ped . An ingenious device has b een developed wh ich mon itors classroom no ise l evels and can be se t to s how the m i n u tes remaining un til rec ess or a special trea t . When no ise levels go over a s p ecifi ed leve l , the clock s tops ru n n i n g . Portable event recorders h ave b een develo p e d th a t perm i t the opera tor to i n d icate the occurrence of any selec ted behavi or by pushing a bu tton that causes a pen to make an ink line on a s trip of moving paper . With fi ve bu ttons and fi ve pens, fi ve separate behaviors can be recorded si m u ltaneously by usi ng all the fin gers an d the th um b of one han d . By hol d i n g the b u tton down until the behavior s tops, you can make a "real tim e" rec ord of the durati on of the ' b e havior . The accu mulating totals of coun ters like those u sed for scorin g golf also represen t mechanical data collec tion of a sim ple sort. These may be u sed by ind ivi du als to record their own " u rges to smoke or eat or do o ther u n d esirable h abi tual behaviors . " They have the advan tage of req u iring less effort (push the bu tton to record the urge) than wri ting down the u rges . In b i ofee dback, the observ a t i on of the d esired phys i ological change is always n1 ade by a m achine wh ich then tells the person producing the change how he or she is doing . By g i vi ng fee dback on the form erly uno bserva ble b i olo gic al s tate, these machines make i t possible for the p erson to modify p hysiological responses, n1 uch as see ing progress on a ch art allows a person to modify more d i rectly accessible re s ponses . Te ac h i ng n1achi nes usually allow the learner to comp are an swers w i th the answer key after each res ponse . This lets the le arner ob serve d i rec tly h is or her level of acc u racy . As we noted for chartin g, knowle dge ( fee db ack) about being s uccess ful n1 ay be a pow erful re inforcer . The s econ d stage of pla n n i n g a con t i n gency ma n a gement program i s speci fy­ i n g observa t i on procedures. such as focal i n dividual or t i me-s a m pli n g tech­ n i ques. R ecords of observa t i on s are called cha rts , a n d chart i n g may i n fluence behavi or. O bserva t i on i s requi red for precise con s equa t i on of t arget behav­ i ors a n d for program evaluat i on . Mult i ple b aseli n e measures of behavi or b e­ fore, duri n g, a n d after con sequa t i on a i d i n program evalua t i on .

Co11se q 11n tio11 The l a s t s tage of the SOC model is ac tually d elivering the consequences of the s pecified behaviors of the target persons accord ing to t he rules of the s pec ifi e d

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contin genc ie s . As has been previously discussed, conseq uation s hould be i m ­ m ed i ate for b e s t results , an d th is req u irem en t i ncreases in importance a s the i n tell i gence level or s tability level o f the targe t p ersons decreases . As we have also seen, a goo d system of secon dary reinforcers can " b ri dge the gap" be tween prim ary reinforcers, as long as these second ary re inforcers are them selves deliv­ ere d as i m m e d i ately after the desired response as possible . We have seen that the d egree of concreten ess of secon d ary reinforcers tha t can b e use d effectively i ncre ases as i n tell i gence level an d/or stability- a dj ustment level decre ases . Thus, poker chips or som e other p hysical sign of the correct response m ay h ave to b e given for every correct response w i th a h ighl y re tarded i n d ivid ual , wh ile a n a d u l t m ay b e a b l e t o change b ehaviors w ith only the second ary re inforcem en t o f see ing h is d a il y record of undesirable b ehaviors show d ecreases . Whatever t he type of reinforcers em ployed, however, and whatever the types of contingencies l inking the t arge t behavi ors to those re inforcers, on e rule applies in all cases : B e Consistent . Th is m eans that you m u st o bserve accurately an d resis t be ing pressured i n to gran ting unearn e d " bootleg" re i n forcers on on e h a n d or hol d i n g back from the deserve d delivery of an aversive conseq u ence on t he other . If the targe t person has contrac ted to turn in a paper by a s pecifi e d due date to prevent i ts being m arked down (active or S id m an avo i d a nce con ­ t in ge ncy) , the p enalty s hould never b e waive d . To d o so wo uld reinforce p ro­ crastination and dawdl ing, and shapes t he b e havior of t he student's beco m i n g fac ile in gen erating ever m ore creative excuses instead of learn ing t o do pap ers on t im e . No re sponsible college professor ( or teacher at any l evel) would w is h to do such a horrible thing to a student! The respon sibl e an d h u m an e ( in the long run , anyw ay) course of action is, as M alott p hrases i t, " NOTHING IN MOD­ ERATI O N ! " This m eans that your res ponsib i l i ty to com m un icate your inflexible con t i n gencies cle arly is m ore than a m oral o bl igati on . If the targe t persons do not know what you expect and if you rein force only behavior conform i n g to your rules, then b o th you an d the " m o dify ee s " m ay extingu ish . This does not mean that you s hould not l is ten to com plaints abou t your program . Rather, you s hould t hi nk abo u t them carefully . La ter, e i ther when you h ave reache d yo ur b e havi oral o bj ective s or you are s a dly s urveying the ruins of w h at had once b een a pro u d program , you s hould take them i n to account in design i n g subse­ quent plan s . Some changes i n conse q uati on s hould b e plan n e d for a t the begin n i n g . If you ho p e to have your targe t persons hol d onto the ir b e havioral gains after the y h ave left y o u r program or after you have ended y o u r efforts, y o u m u s t shape behaviors th a t can b e reinforced by the environ m ent or by the p ersons the m ­ selve s . This i s called shap i n g functional behavior. An exam ple would be tra i n ­ i n g a c h i l d t o rea d . O nce re ading i s m a s tere d , the con ten t of the material re ad w ill reinforce it. Once prosocial behavi ors are mas tered in c h il dren w i th e m o ­ tional problem s, the more positive reactions o f sign ifican t o thers i n their en vi ­ ronm en ts may m a intain the new behaviors . S i m ilarly, pra ise fro m the ir friends m ay m a intain newly acq u ired " avo i d ance of smoking b e haviors" in form er s m okers . T he m a tter of shaping functional be havior is one wh ich has on l y rec cn t l y b een given suffic ient a tten tion by b e havi oral modifi ers . Even today, m a n y pro-

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gra m s inclu d e no provisions for followu p s . Rightly , the critics o f the beh avioral m o d i fication m o ve m e n t h ave noted that even though children or w ard p atients m ay indee d b eh ave i n ways j u dged as more app rop riate by the m o d i fi ers, these gains m ay vanish when the reinforcers van ish . W here continued envi ron m en t al con trol is present, such as on a m ental ward for long- term patients, such crit i­ cism s may not b e very im portan t. Even b e h avioral gains which m u st be main­ tained by continuing contingency management p rogram s m ay make a ward m uch m ore reinforc ing for b oth pat ients and staff. Pl anning for the day when the t arget p ersons will leave your kin dly atten ­ t i o n , however, is vi tal in counseling an d school sett ings . In cou n seling, shap i n g functi onal b e h avi or m ay take the form o f tra i n i n g the client t o apply contin gency man agement tec h n i q u e s to h i m self, along w i th other self- help skills, such as relaxation tech n i q u e s . The coun selor should a ssign to the cl i en t sim ple "self­ help problem s" and then reinforce the client for arrivi ng a t s uccessful comple­ tions of them . If t he new skill s help the clien t obtain reinforcers on h is own, they will u s u ally be maintained, although occasional " bo osters" m ay be need e d . Wi th school c h ildren, the m o st s uccessful ap pro ach m ay b e grad ually withdraw­ ing, or " fading o u t , " the overt re inforcers . The m o d i fi er s hould o b serve carefully for signs of schedule strain as the sche dule o f rei n forc em ent b ecom e s leaner and lean er . Disappearance o f n ewly ac q u ired positive b e h avi ors signals a n eed to " back u p " and restore some of the programm e d rein for�ers . Another cri ticism of contin gency m an agement p rogram s is that they m ay reinforce und esirable l evels o f com petiti on . Such program s, however, can also be d esigned to i ncrease coopera tion . B artlett and Swenson ( 1975) based re infor­ c ers for low l evels of d isruptive beh avi ors i n fifth grad ers on the total d isruptive b e h avi ors of the m em b ers o f a gro up of p u p il s seated at a partic ular table . The en tire table's consequation was yoked together . The resu lt was that p eer pressure was exerte d on unruly indivi d uals at each table to p erforn1 well at the " good behavi or gam e , " a gro up con tingency system first d escri bed by Barrish, S au n d ers, and Wolf ( 1969) . Another feature design e d to red uce competition was havi n g a bsol ute cri te­ ria for rei nforcemen t . All tables e m i tting less d is rupt ive behaviors than the mean n u m b er of disruptive behavi ors o b served during the basel i n e 1 p eriod were allowed to go to recess early . Those acting o ut at about basel ine levels went to recess on time, and those havi ng a grea ter than average n u m b er o f i ncidents at their table went to recess late . Thu s, all ta bles could " w in the gam e" each time. Such gro u ped con seq u ences have several advan tages . First, they are easi er to adm in is ter, since gro u p rather than i ndividual record s are req u i re d . Secon d , they m a k e be tter use o f natural peer- based soci al reinforcers t o s u p plement the effects of reinforcers controlled by the mod ifi er . Wi th relat ively " norm al" target p erson s, s uch gro u p con tingenc ies are almost always n1 ore e fficient than i n d i ­ vi d u al con tingencie s . O ne highly d isruptive in divi d ual , however, m a y d e ­ m oralize his or her gro u p a n d disrupt an en tire program . S u c h an i nd ividual s hould be exposed to ind ividualized aversive con seq u ences, such as time o u t ( isol ation) for extre m e an tisoc i al acts, o r should be treated as a "gro u p o f one . "

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G rouped con tingenc i es are , of course , lim i ted t o environ m en ts s u c h as schools where sim ilar goals are appro priate for several people s im ultaneously. P a ir or fam ily con tingenci es may be useful in marriage counsel in g . Consistent delivery of reinforcers j ust after the emission of target behaviors is an essential step in effective contingency management. Because it is often difficult to deliver a primary reinforcer often enough and precisely enough , secondary reinforcers are u sed to bridge the gap between target behaviors and eventual primary reinforcement. The final goal of most programs is to shape functional or self-reinforcing be havior.

So far, t h is chapter has presented the principles of e ffective contingency m anagemen t . Now we can turn to the wide range of situations in w h ich such tech n i q u es are applied an d how the princ iples previously p re sented are used in each of these situations . As you rea d through these summ aries o f various recen t studies, look for the principles of ap p l icati on as well as illustrat i on s of the p ri nc i ples o f o p eran t learn ing theory presen ted i n Chapters 4 and 9. These exam ples of uses of princ i ples , design ed to help you integra te theory w i th a p pl icatio n , may s ugge s t how you can eventu ally des ign c ontin gency m anage­ m en t program s to aid you in your careers . These real world applications m ay also help you in e valuating the argu m ents o f p erson s o pposin g and s u pp ortin g the u se o f contin gency management techn i q u e s to shape and con trol behav i or .

OPTIONAL SECTION S elected Examples of Operant Appl ications

A n In troductory S 111orgasbord Proposals for the i deal l iving arrangements h ave spanned the history of western civilization fro m Plato's Rep u b lic to Skinner's Wa lden Two ( 1948) . . . . A m aj or prob l e m that any experimen tal living arrangement m ust confron t is that of shar­ ing the b a sic work of the comm u n i ty . Informal acco u n ts suggest that con tempo ­ rary c o m munes experience a b reakdown i n the basic housework req uired by the group . . . . the group could not provi de i ts members with such po ten tially powerful reinforcers as a clean a n d neat l iving environ m ent, well - p rep ared meals, and clean plates a n d silverware . F urthermore, the withdrawal of such reinforcers could lead to an increase in a ggressive i nterpersonal b ehaviors . . . [ Feallock and M iller, 1976 , p . 277 ]

A dream o f any applied sc i ence of b eh avior has been to create the basis for a better way of l ife . Altho u gh Skin n er's u topia, as presen ted in Wa lden Two ( 1 948) , has been given reality as Twin Oaks com m u n e (K i nkad e , 1973) , i t has not b een bu ilt on the rigoro u s experimen tal basis envisioned by S k inner . Fe allock a n d M iller have atte m pted t o remedy th is shortcom in g through the ir work w i th a coed coop erative ho u se a t the U n i versi ty o f Kansas . A feature o f the labor cred i t system i n Wa lden Two was that the value of a given j o b was dependent upon i ts p o pularity. Th is led to d es irable j o bs, such as

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p icking flowers, paying a small fraction of wh a t was paid for so p p i n g sewers . The Kan sas ho use incorp orates th is fea tu re , with the values of the most and least popu l ar 1 0 p ercen t of the j o b s adj usted for popularity . A t the beginning of the ir proj ect , som e o f the 30 stu den ts living in the house expressed the view th a t a clean hou se was i n trin sic reward enough . To tes t this, cre d i ts for cleaning were trans ferre d to painting the o u tside of the house . At the end of the 18 d ays, the residents demanded the res um p tion of cleaning cre d i ts after serious deteriora­ t ion in the cleanl in ess of the house h ad occurred . Amount of cleaning j ob s complete d prior to the change from a cre d i t system w a s 9 6 p ercen t (basel ine 1 ) . D uring the change , th is percen tage fell to 35 p ercen t before contin gencies were res tored for cle an i n g . D uring the b asel ine 2 p hase , the com pletion ratio aga in reached 96 p ercen t . The percen tages of c omp l eted p ain ting j o bs, which only paid cre d i ts d uring the on -contingency p h ase , were 3 p ercen t (baseline 1) , 99 p ercen t ( on con tin gency) , and 0 p ercent (basel ine 2) . A secon d question raised by house members concern ed the n ecessi ty o f m aking credits cont ingen t u p on the w ork's s uccessfully passi n g the gaze o f student inspectors . " S o m e members suggested t h a t i t would be n icer if there could be trust in the ho use , so that the members who agree d to do a j ob would n o t h ave to h ave the ir work inspected and cre dits awarded on the basis o f th at in spection" ( Feallock and M i ll er, 1 976 , p . 281) . Aga i n , a sim ple reversal design was u se d , with the in terven tion phase o f cre d i ts no t con tingen t upon inspecti on lasting 35 d ays and the basel ine 1 and baseline 2 p h ases l as ting 36 a n d 25 days, resp ectively . During baseline 1, 96 percen t o f all cleaning j o b s passed inspec­ tion . D uring the in terven tion phase , th is ra te h ad dropped below 60 p ercen t by the fin al five days. D uring b aseline 2, the rate wen t b ack up to 95 perce n t . I n the original p l an , l abor cre d i ts were convertible i n to ren t red u c tion s . A th ird q ues tion debated was the necessity o f s uch a backup syste m . S om e s tu ­ den ts argued th a t pride o f ach ieve men ts alone s hould be s u ffic i en t . A third experimen t used a des ign with a m i d d l e p h ase i n wh ich all ho u se n1 em bers go t a rent re d uction irrespec tive o f the ir work records . Twen ty- seven o f the 30 m e m ­ bers compl eted less cleani n g j o bs ; and total cl e a n i n g j o b s passi n g i n s pection d ropped from 94 percen t to 67 p ercent d uri n g the "non - b ackup " phase . A qu estion arises about the feeli ngs o f the human s u bj ec ts in such an ex peri ­ m en t . Certainly the econom ics o f a work -sharing plan o f th is type are favorable in comparison with d orm i tories th at have paid clea n i n g a n d n1 a i n ten a nce s ta ffs (about h alf the cost) . B u t w h a t about studen t s a tisfaction ? I n fact, tes ts i n d icated consid era b ly higher s a t is fac t i on for most partic ipan ts . This n1 ay h ave resulted from other procedures b u i l t i n to the sys ten1 . A req u irement for l i vi n g i n the house was passing a q u iz a fter con1 pl e ting a progran1 n1 ed sel f- i n s tru ctional han d book on behavioral techn iq ues . S tu den t acce pta b i l i ty was fu rther i n ­ creased b y havi n g all ins pectors, con t ingency man agers, a n d fin ance man agers be ho use members who h a d passed " m in icourses" in these areas . The first studen t adn1 i n is tra tors, in turn , d e veloped 80 sel f- in s tru ctional manuals and tra i n e d all subse q u e n t peer man agers . As part o f stu d en t self-governance, the cre d i t values for various tas ks could be modified by maj ori ty vote . Th is com­ m u nal house demon s tra ted a viable ap proach to group sel f-control proce dure s .

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While Feallock and M i ller ( 1 976) demonstrated the util ity of behavioral tech n i q u e s in an environ ment in wh ich the participants were involved in de­ term i n i n g contingencies, what o f less democrat ic institu tions ? Hobbs and Holt ( 1976) were able to i mprove sign i fican tly the perc en tages of t i m e s p en t i n ap­ propriate activities b y 125 a dj u d icated d el i n q u ent b o ys fro m aro un d 55 p ercen t to over 78 p ercen t thro ugh u se o f a token sys te m . Tokens w ere b acked u p b y d ances a t a g irl's training school , cigarettes, toys, candy, soft drinks, access to foo tball and o ther sport events, and e arly release . Cost o f the experiment was o nly $7 . 85 p er boy p er month . The authors rep orted that 14 mon th s after the experiment was concluded, ad m in is trative n eglect of s u p ervision and coord ina­ tion o f the program, coupled w i th an i n sis tence on using the system to pro m o te b eh aviors such as stan d ing s traigh t i n l in es , had resulted i n consid erable pro­ gram d eteriora tio n . The au thors com m en te d on t he d il em m a raise d by providing the powerful tools of b eh avioral con trol to "commun i ty s ystem s whose p rogram in tere s ts may not all b e i n the best interests o f the client" (Hobbs an d Holt, 1 976 , p . 1 97) . O n e answer to the ethical issues raised by Hobbs and Holt is to give even i m prison e d "o ffend ers" more control over the con tingency managem en t pro­ cess . Seymour and Stokes ( 1976) , work ing w i th fou r g irls c onfined in a m ax i m u m -security i n s t itution i n Austral ia, w ere s uccessful i n i ncreasing work b eh a vi ors and reducing d is ruptive behaviors for three of the girls . The girls were allowed to score their own work o u tp u t , although p rovisions for the d etec­ tion o f cheating were b u ilt i n to the system . Th is self- record ing procedure was s uccessfu l in spite o f the fact that a previous s taff- d irected token economy had faile d . A s i n m any other program s of th is typ e , token cost (res p onse cost) provi­ sions were n ecessary to reduce competing behaviors . The girls al so rol e-played p o i n ting out i m p rove m en ts in the ir work to s taff, or "cueing" s taff. The staff (wh ic h was d is tinct from the exp erim ental team) was not aw are of these cues . Both cues and praise from the s taff m em b ers. i ncreased in the l a ter s tages o f the proj ect . The therap is t record ed the c u es and delivered to kens for the girls' efforts to bring their i m provi n g work to the a ttention of the staff. Thus, the to ken s were used to i ncrease the rates w i th wh ic h the girls elicited soci al re inforcers . The s uccess of the response cost p roced ure used to prevent cheating i n the Seymour and S tokes study is p arall el to extensions i nto o ther types of gro u p settings where it i s d esirable t o d ecrease s p ecifi e d b e h aviors . M arhol in and Gray (1976) were able to red uce sharply cash losses i n a s m all b usin e ss by instituting a gro u p response cos t con tin gency . A revers al d es ign w as u se d before the pro­ gram was p erm anently i n s t i tu ted . S hortfalls on b asel i n e d ays were around 4 p ercent of receipts; during "on-contingency" days, they dro p ped to less than 1 p ercent . Total fin es to e m ployees were $8 . 70 p er p erso n . N o t all i n s titutions are d esigned t o b e e i ther pun i ti ve or profi t making. O n e s uch i n st i tu tion i s m arriage . I srael G ol d iamond has b een a p i on eer in develop­ ing self- ap pl i e d b eh avior tech nologies i n wh ich the professional mod i fi er serves as coach , con s ul tan t, and evaluator . The following case illustrates h is approach, applied to p artic ipan ts i n a failing marri ag e . The couple concerne d had b een m arried for alm o s t t e n years an d had l im ited

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the m selves to sexual relation ships about twice each year . This was blamed on the h usband by b o th parti es . They were both i n tell igent professionals, Roman Cathol ics, an d d e term in e d to maintain the m arriage if only they could get sexual behavi ors starte d before the wife was " driven" i n to extram ari tal affairs . It was suggested that the husband try reading Playboy to i n i tiate amoro u s activity . He feel asleep re ading it . The wife had al most exti n gu ishe d on "h u sb a n d-shap ing" b e h av ior : I don't know what reinforcements I have . The characteristic of good rei nforce­ m en t is that it can b e applied i m mediately and is i m m e d i a tely con s u m e d . I coul d wi thhol d supper, b u t tha t is not a good reinforcer, because I can't turn i t off and on . I can't a p ply [sexual] d epriva tion because tha t's my problem . I don't know what to do . [Goldiamon d , 1 965, p. 857 ]

Part o f the problem was that the h usband was a rising busi n e ss executi ve who also atten d e d even ing courses an d was e ither too b u sy or too tired to make advances towards his wife . He offered to schedule h is wife in his ap pointment b ook for two even i n gs a wee k . In s p i te of h is wife's dubious attitude, ch arting his " wife attent ion" ap pointm en ts was i n itially effective . After two weeks, however, he began to cancel these appointm ents an d i t was n ecessary to search for an effective backup rei n forcer . Both husband and w i fe took p ersonal groo m ­ ing very seri o usly . S he visited her beautician weekly a n d he , h is barber . Their clo th ing was always fres hly dry clean e d . When term ination of all such affectation s was made the contin gency for m isse d appoin tmen ts, van i ty su cceed e d where a l l else had fai l e d . Beh avi oral tech n i ques c a n also b e u se d t o i m p rove the envi ron m en t . H ayes, Joh nson , and Cone ( 1 975) were able to reduce li ttering on the gro unds of a federal youth correctional fac i lity in sp ite of a lack of p u b lic s p i ri te d n ess . The ir m etho d was a sign i fican t advance over previous m etho ds, i n which re inforce­ m ent was contingen t on the amount of trash turned in , th u s exposing the s u b ­ j ects t o the tem ptation o f generating n e w trash t o supplen1ent the i r re inforcers . H ayes and colleagues mention one case in which ch ildren living in a public ho u sing proj ect e m ptied trash cans into the ir collect i on sacks an d collected the larger pi eces of trash while leavi ng small p ieces b e h i n d . To avoid these problems, the experi m enters s u rrept itiou sly d istributed a few items o f marked li tter i n each o f the s tu dy areas on each of the on­ contingency days . Unlike the previ o u s beh avi oral appl ica tions for litter con trol , this proced u re provi des a variable ra tio sche d u le o f con trol as compared to the volu n1 e/fixed ra tio schedules of " a n1 o u n t- based " program s . Because the marked items were coded in a way known only to the experi n1 en ters, there was no possibility of the youths' pic k ing up only n1 arked items . Three of the areas included in the study were "seeded" with marked i te m s . The youths were told when mark ing m i gh t b e done . Baseline data was collected for the th ree "seeded" areas before they were firs t n1ark e d . The average red uction in li tter in the m ark e d areas during the times when they were m ark e d was 7 1 . 3 p ercent . There was actually an increas e in litter in the unmark e d area, wh ich may re flect a behavi oral contrast e ffec t . Of the youths el igible to p artici p ate in this program , '

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25 p ercen t did so . I n add i tion to special privileges, such as b e i n g allowed i n to the camp coffee house past regular hours, a total o f $14 . 50 was e arned by all p articipants o ver the 42 d ays of study . This tec hn ique is i n teresting because o f i ts excellent cost-effectiveness rati o , because o f the absence of aversive con ­ tingencies, a n d b ecause i t does not req uire m uch s taff time or i nterpersonal skills ( as in convincing a j uvenile delinquent that he wan ts to collect trash) . A variation o f th is system use d in a fores t service area ( Powers, Osborn e , a n d Anderson, 1 973) paid $. 25 for full bags of trash b u t also incorporated a lo ttery system which paid $20 . 00 to the p erson whose lottery ticket, accepted i n l ieu o f c a s h , h a d b een selected . This m e thod m ay b e superior for areas in which cheating is not a pro bl em . Even b e haviors usually though t o f as treatable only through m edication h ave been successfully modified through contin gency m a n agemen t . Zlutnick, M ayville, an d M o ffat ( 1975) noted that specific behavi ors reli a bly pred icted the occurrence o f epilep tic seizures in children . These b e haviors varied from arm raising to faci al grimaces . The au thors hypothesized that t he p reseizure behav­ iors were p art o f a behavioral chain ending wi th the full- blown mo toric, or lo ss- o f- atten tion, seizure . N o ti n g some earl i er research that sugges ted that in­ terrup tion o f the behavioral chain could preven t the occurrence o f the seizures, they developed aversive consequences for the p reseizure b e h aviors . These con ­ sisted of shouting " N o !" \vh il e gra b b i n g the subj ects with b oth h an ds and shaking them vigorously . For one subj ect , this system was supplemen ted by g i vi n g soci al and primary reinforcers contingen t upon the subj ect's halting the preseizure behavior . During b asel in e 1 , d ata was collected on the frequencies of seizures and preseizure behaviors . The interrup tion p rocedure was then insti­ tuted an d rem ained i n effect on an ongoing b asis except for one d ay of b aseline 2 (reversal) m easuremen t . Four o f the children s howed significant d ecre as es in seizure frequencies, an d preseizure b ehaviors d eclined in the o ther three chil­ dren . Seizu res returned during the reversal d ay and decre ased once the in ter­ ru p tion p rocedure was reinstitu ted . A n advantage o f the in terruption procedure was that p arents an d teachers were able to l earn i t -thereby reducing the n ee d for contin ued p rofessional supervision and lowering the cos t of tre a tm ent . Before the p arents adm in is tered the treatments, they were each train e d for 5 hours by the investigators, fol lowed by one to three p hone c alls p er week to mon itor p rogress and collect data. This app ro ach typi fies the triadic model ( therapeutic pyramid) described by Tharp and Wetzel ( 1969) . In this model, the change agent, or person who actually delivers the rein forcers, is n ever the h i ghly paid p rofessional . Instead , the pro ­ fessional d evelops an d i mplem ents programs an d teaches techniques to non­ p rofessionals or paraprofessionals . Rather than act i n g as a therap ist in the con­ ventional sense, he or she functions as the supervisor and consultant at the top of the " therapeutic pyram i d , " to ensure tha t the m ed iators, or change agents, c arry out instructions . Advan tages of th is appro ach include more contact time be­ tween clien t and change agent (ch an ge agen ts are usua lly persons normally havi n g extensive contact w i th the client or target p erson) and a good cos t­ effectiveness ratio .

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Although almost all the ap plications p resented thus far have dealt with m o di fications of human behavior, the operant m e thodology was origin ally de­ veloped thro ugh a n i mal research a n d is thu s adm irably s u i te d to animal appli­ cation s . A p i on eer i n using behavioral technology to produce p ractical benefits by m o di fy i n g an i mals ' behaviors is Hal M arkowi tz , form er direc tor o f the O re­ gon Zoological Research Center at the Portlan d Zoo . Dr. Markowi tz' s work has important i m p l ications both for a n imal h usban dry prac tices in zoos a n d for theories o f motiva tion . A m aj or p roblem i n zoos is tha t an imals fed the ir daily ra tio of foo d once a day become bore d , i n ac tive, a n d , i f dom i n an t, obese . Thus, the low - ranki n g a n i m als m ay end up m alnourished while the h igh-rankin g a n im als suffer t he effects of easy living without the n ee d to work for their foo d . The i nactiv i ty engendered by sloth is o ften not d is tingu ishe d from the i n activi ty resulting from sickn ess . I n active an im als frustrate the v i ewin g p u bl ic, who may resort to fee d­ i n g the anim als "j unk foo d , " thereby thwarti n g the efforts of the zoo d ietitians . Dr. Markowi tz tackled these problems by develo p i n g d e vices which could be operated by the a n imals to provide foo d . The a n i m als, o f course, had to be shaped to use these exten sions of Skinner box methodology . One exam ple of this approach, which fea tured a two - s tage learn ing prob­ lem , could b e seen in the gibbon (a lesser ape) d isplay of the Portl a n d Zoo . First, the a n i m als had to solve a l i ght- dark discrim in a ti on task when the compu ter­ ' controlled mach ine notified them, by a comb i n ation ot b uzzer and l igh t cues (the d iscri m i native stimuli, or S 0s ) , that reinforcem ent would be available . Then they had to swing arm over arm across the ir cage to the second ap para tus, where they pulled a lever which caused an autom atic feeder to release b its o f h ighly preferred food . I n a n ice extension of rei n forcement principles, the i n it ial S n was triggered by a human's putti n g a d i m e in a slo t of a box . An i n s truction panel explai n e d the purpose of the appara tu s . Over $3000 was collected by this box i n one year, to b e used for the research progran1 . O ther i n teres ting illustrations included train i n g d iana monkeys to perform a sequence of behaviors which resulted in the ap paratus d is pen sing a token . The monkeys could then e i ther spend the ir tokens or hoard the n1 . S o n1etimes the monkeys were even o bserved sharing token s ! Yo ung mon keys born after the program was i n i tiated d i d not need the elaborate s h a p i n g procedures re qu ired for the ad ults . Instea d , they success fully n1o d eled the ir parents' behavi ors (M ar­ kowitz , 1974) . Data collection fron1 the d iana n1on key and the gibbon d isplays was auto n1 ated, and enorn1ous qua n t i ties of i n forn1 a tion were gathered . Other pro ducts of th is unusual ap proach to zoo d isplays i ncluded s n1 all wild cats (servals) that chased " flying n1eatballs , " a bear that could trigger a fish - throwing catapult by nona ggressive growls near a h id d en m icrophone, a n d a man drill monkey who played a reac tion - t i n1 e ga n1e w i th zoo vis i tors for one d ime a game (M arkowi tz, 1975a) . Wh ile visiting H al Markowitz d uring the fall of 1977 , the a uthor had the opportun i ty of losing three games i n a row to the s peedy baboon . Benefits of these progran1 s i ncluded more active a n d hence healthier a n i ­ mals, more i nteres ting d isplays for the z o o - g o i n g p u blic, an opportun ity to notice illn ess earlier (sick an imals ceased opera ting the apparatus) , less boredom

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for the anim als, an d opportun it ies for research . This last advantage allowed extensive com parisons of many species' ab i l i ties on a variety of learn ing a n d simple concept-formation tasks . As the animals became m ore active , p a tholo g i ­ cal behav i ors s uch as infant harassmen t were reported to h ave d ecreased (M ar­ kow i tz, Schmidt, an d Moody, 1 977) . Some obj ections, however, were raised to this program . First, i t was sug­ gested that situations s uch as h avi n g d i an a m onkeys work for tokens are u n ­ natura l . H a l M arkowi tz defen d ed h is work i n a n article en titled , appropriately enou g h , "In Defense of Unn atural Acts Between C onsenting Ani mals " ( 1 975a) by pointing out that animals' b e haviors in bare enclosures are not only equally unnatural, b u t m ore likely to be harmful to the ani mals. A second obj ection was that i t is cruel to deprive an imals of fo od in order to force them to o perate the devices added to t heir environmen t s . M arkowi tz coun tered by noti n g that all an imals are given all the food they can eat at the end of the testing day . They rarely failed to earn all t he foo d t hey wished by operatin g the devices an d became extremely upset when the m achines were d isconnected for m ain te­ nance . The ostriches even i gnored b i ns of " free" peanu ts to work a machine that d is pense d i dentical peanuts for correct responses (M ark owitz, 1 975b) . The ill u s ­ tration t h a t t he animals' behaviors seem ed to h ave more to do wi th depriva tion of the opportun i ty to con trol effectively som e aspect of their environments rather than with h unger m o tivation m ay represent a s pecial case o f t he Pre m ack prin ­ ciple . The anim als were deprived o f the opportuni ty to em i t food- gatherin g be­ haviors ; i t was the opportun i ty to e m i t these behavi ors (which would occur frequen tly in the wild) that provided m o s t of the reinforcemen t . The general implication is tha t working for a living is, in a sense , as prim a ry a re inforcemen t a s drive red uction of the typ e discussed b y H ull (Chapter 3) . This is in agree­ ment with H arlow's ( 1 953) observa tion that m onkeys will solve p uzzles for the mere reward of b e i n g able to m an i pu late som ething as well as for foo d . S o m e n e w t e r m s i n t rod u c ed i n t hese su m m a ri es o f stud i es we re: ( 1 ) t o k e n c o s t , o r t a k i n g away t o k e n s c o n t i n g en t u p o n u n w a n t ed b e h av i o r , ( 2 ) b a c ku p syste m , o r a sys t e m o f m o re p ri m a ry rewa rd s t o rei n f or c e t h e effects of t o k e n s o r p o i n ts , (3) revers a l d es i g n , a n ot he r t e r m f o r m ul t i p l e bas e l i n e d e si g n , a n d (4) t r i ad i c m o d e l , o r t he ra p eut i c py ram i d , i n w h i c h a p rofessi o n a l t ra i n s o t h e rs t o b e t h e c h a n g e a g en ts, o r p e rso n s o bs e rv i n g a n d c o ns equat i n g b e h av i o r .

Applica tions of Con tingency Ma11 age111 ent to the Schoolro o111 Most applications of con ti n gency m anagement principles have concentrated on t he m o d i fication of overt behaviors rather than promoting the learn i n g of aca­ d em ic ski lls . These techniq u es have been particularly wi dely used in s pecial e du cation . A n example of th is approach was the work o f Cooke and Apollon i ( 1 976) with four handicapped children enrolled in an experimental classroom . It is of interest methodologically because three o ther children enrolled in the classroom served as con trol subj ects-a rarity in o perant application s , where reversal or m ultiple baseline design s are comm on . D urin g baseline 1 , freq uen -

2 88

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c ies o f s m il i ng, sharing, posi tive p hysical con tacting, verbal com pl im enting, and combinations o f these behaviors were recorded . Each of t he fo ur behaviors was then trained in s uccessive five- day periods . Train i n g methods included the trainer modeling t he desired beh avi or, as suggested by Bandura's social learn ­ i n g t heory, p raise con tingen t u pon the specified behaviors, and d irec t instruc­ t ions . Following each d ay's training session , the generalization o f the trained behaviors to interact ions with the un trained children was note d . Following training, followu p observation of generalization was conducted over a fo ur­ week period . All trained subj ects increased the frequencies with whic h they emi tted the s peci fied positive behaviors during the tra i n i n g periods, and three o f t hem s howed continuing generalized increases i n t he followu p ob servations of their i nteractions with the u n trained subj ects . The three u n trained subj ects s howed i ncreases also , although relatively less so . These increases were ex­ plained as ei ther the result of the untrained children's m odeli n g of the trained children or the result of soc ial-reciproci ty effects . The control of p u p il behavi ors is not lim ited to soci ally relevant behaviors . Behaviors related to cognitive function i n g may also be altered . Glover and Gray ( 1 976) were able to demonstrate behavi oral control of fo ur behavi orally defin ed "creative" behaviors in eight fo urth - and fifth- grade chil dren . The beh avi ors were (1) num ber o f d ifferen t responses assumed to reflect fluency, (2) the pro­ duction of a large variety of ideas assumed to reflect flex�bility, (3) the develop­ ment, em bellishm en t , or completion of an idea labeled as " elaboration , " an d (4) the use o f i deas " that are not obvi ous or banal or are statistically infrequen t" (Glover and Gary , 1 976, p . 79) . Leavin g asi de the s u bj ective nature of the last category , you will no te that each of the u n d erly in g in tern al facets of creativity has b een tied to an operationally defin ed class of verbal dependen t variables . The verbal data were genera ted during class hours as p art of writing assign ­ ments . During on-con t ingency periods, p o i n ts were award ed based on the fre­ q u encies of the s pecified behavi ors ; during basel ine periods, the students' pa­ pers were all marked "good" and everyone was tol d , "You are d o ing very well . " The res ponses were scored by two grad uate s tu den ts i n educational psychology who d i d not know the purpose o f the exp erim en t nor the variables involve d . This is called a double-blind procedure , a s the s tu d ents were also " bl ind" to the purposes of the rese archers . S tu d ents were also tested on the To rra nce Te s t of Cre a tivity before (pretest) and after the contingencies were put i n to effec t . They showed a s tatistically sign ifica nt increase in their creativi ty score s . This m ight re flect a real gain in creativi ty or s i mply learning to do more of the be haviors measured on t he Torrance tes t . Each of the dependen t variables was rewarded d uri ng one o f the fo ur experimental sessions . Each of the measures increased o ver basel ine mea­ sures and, moreover, showed most of t he increase only d urin g the experimen tal session , when that particular class of verbal beh aviors was s u bj ect to the point contingencies . The points gained were credited to one of the two four-ch ild team s . The winning tean1 was allowed to go to recess 1 0 m in utes early and each team member received a carton of m ilk and some cookies . This group con­ tingency is sin1 ilar to that d iscussed earlier in th is chapter ( Bartlett and Swenson,

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1 975) . The authors s u gges t that their procedures m ight be u seful to teachers who wish to raise the freq u ency of creative behavi ors i n story writing and problem solvin g . A b roader i m pl ication o f th is study is that s u pposedly s terile o pera n t contin gencies c a n b e used t o max im ize s uch complex b e havioral patterns a s creativ i ty . These results directly contrad ic t some critics' contention s t h a t behav ­ i oral m o d i fica ti on techniques are the enemy o f cre ativity . Although the preceding was a n example o f trying t o i ncrease a som ewh a t unusual class of b ehavi ors, more recen t stud ies h ave addressed themselves to the problem o f fin d in g the most e ffective and efficient m eans o f producing m o d i fications of behavior i n general . H u n d ert ( 1976) com pared giving tokens, taking tokens away for failure to e1nit the target behaviors, and b o th giving tokens and takin g token s away . The b ehaviors m o d i fie d were p ro duction of correct finished arithmetic p roblems a n d paying a ttention to the teacher and h is work . There were no d ifferences between these procedures, and all o f them produced large gains in the six elementary school students . During the baseli n e 2 (with drawal of token) m easuremen t p eriod , i nattention , b u t not p ro d uc ti on o f arith m et ic problems, declined to baseline 1 l evels . I t m a y b e suggested that once a com petency is learned , the improved p erformance is likely to be self­ rewardi n g . Not paying attention , however, may b e i n trinsically m ore reinforc­ i n g than paying attention-especially i n m any arithmetic classes . A nother d irect comparison o f the effectiveness of two m e thods o f modi fy i n g behavior found d irect reinforcement to be superior to a m odeling procedure . Bondy and Erickson ( 1 976) a ttempted to increase the rate of q uestion asking by 12 retarded ch ildren . One gro u p got p o in ts to b e exchanged for food , one gro u p had q u estion-asking behav i ors m od eled b y a trainer, an d one group both re­ ceived p o i n ts and had the behaviors m od eled . The m o deling procedure , o f the typ e d escribed by Bandura (Chapter 9) , had only a m i n i m al effec t . The m o d �ling plus points gro u p learned the fastest, b u t their final level of performance was no h i g her than the p o i n ts-only group . This s tu dy s u p p orts the author's o p i n i on that d i rect shaping o f behavior is the superior proced u re to u se with retarded and d is turbed i n d ividuals . Another aspect o f program effectiveness is that of the behavioral control exerted by d i fferent rein forcement p arameters . Robertson , DeReus, and D ra b ­ man ( 1976) compared giving feedb ack t o children about thei r s uccess i n emi t­ ting less d isru p t i ve b e haviors w i th givi n g them e i ther contingen t or noncon t i n ­ gen t tutori n g . The t u toring o f these h ighly d isru p t i ve and academically slow second graders was done by e i ther fifth- grade volu nteers or college students . The 1 8 children were d iv i ded i n t o fou r groups an d all children received each type o f reinforcemen t con d i tion a t some point in the experim en t . All four gro u ps then entered a last phase o f the s tudy, d u rin g wh ich they were again g iven feedback on their d isru p t i ve behavi or but no tutorin g . It was fou n d that feed ­ b ack alone was n o t sig n i fican tly effective in reducing the d isruptive behaviors . Performance d uring the fin al feed back p h ase was better than d uring the i n i t ial feedback-only p h ase . This s uggests tha t fee dback m igh t be used as o ther types o f reinforcers are faded o u t . P up ils ' behav i or i m proved during all types of tutorin g . This i m provement, however, was m uch more marked when tutori n g

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was contingent u pon reductions in d isruptive behaviors . I t see med to make no d i fference if the tutors were college stu d en ts or fifth - grade peer t u tors . This stu dy is o f interes t becau se i t suggests that ava ilabi l ity o f help from o ther people may be an effective rei n forcement system if it is made contingent u p on low rates o f " acti n g -o ut" behaviors . Such an ap proach would seem b oth practical and i n expensive . A d is advan tage would b e the p ossi bil ity that p u p ils most in need of special help migh t be d en i e d s uch help by reason of their bad behavior . Since one cause o f their bad behavior m i gh t be fru strat i on with their poor academ ic p erformance, contingen t tu toring m igh t p erpetuate a vicio u s circle in wh ich academic fru stration leads t o aggressive behavior i n class, wh ich prevents tu toring and keeps academ ic performance low . While i t is u s u ally considered desirable to eli m in ate d isru ptive behaviors, some behaviors are only d isrup tive when they occur too frequ ently. An example is talki n g out in class . Even though frequ en t talking o u t may b e annoyi n g to teachers, the thought o f training silen t , sullen s tu den ts is no more pleasing . Rather, what is d esired is to reward low levels of talkin g - o u t behavior and to have aversive events contingent u p on h igh levels . As we noted in C hapter 9, one of the points of stren gth of Skinnerian theory has been the d elineation of the effects of complex sched ules of re inforcemen t. O n e of these schedules, y o u may recall, was the DRL (differen tial reinforcem ent of low levels) sche dule . Deitz (1976) exam i n ed three types o f DRL procedu �es in behavi orally d is­ turbed children . The first method is called the spaced resp onding D R L metho d . In th is m etho d , only responses separated from each o ther b y in terresponse times (IRTs) over a specified criteria are reinforc e d . The second n1 ethod is called the full-session DRL method. If the total n u mber of target responses e m i tted d uri ng a given time period falls below a specified n umber, rein force n1ent is delivered . This was the m ethod u sed in the "good behavior game" developed by Barris h , Saun d ers, and Wolf (1969) and u sed in modified form b y Bartlett a n d Swenson (1975) . The third method is the interval metho d. If less than two talking- o u t responses occurred d uring the prescribed i nterval, reinforcen1 en t was delivered when the interval en ded . If a second response occurred d uring the in terval, the in terval timer was reset and reinforcement was pos tpon e d . All three versions of DRL schedules reduced talking to abou t 15 percen t o f basel ine ra tes . As these applications demonstrate, the s uccess o f researchers presen ted here shows that application of opera nt princi ples is a n effective ap proach to classroorn n1 anage1n e nt . The would-be contingency n1 anager, however, m ust be aware that this approach is extremely l i tera l . Tha t is, you tend to increase the emissi on of all reinforced behaviors regardless of whether you actually wish to rei nforce all these effects . In a d d i t ion, the teacher's enth usiasm, or lack of i t, may d etermine the s u ccess of a gi ven projec t . The teacher's expectancies of success (R osenthal effect) or the childrens' res ponses to the novelty of new classroom proced ures ( H awthorne effect) n1 ay b oth confo u nd your evaluation of the effec­ tiveness o f a con tingency management procedure. Having an experimentally na ive observer collect data , apply placebo treatments, s uch as the noncon ­ tingency tu toring u sed in the previous exampl e, and use multiple basel ine de­ signs all help to reduce errors i n evaluatin g the s uccess o f programs .

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C o n t i n g e n cy m a n a g e m en t m e t h o d s a re effe ct i v e i n educat i o n a l sett i n g s. Wi t h ret a rd ed a nd/or h i g h l y d istu r b ed c h i l d re n , d i rect s h a p i n g o f b e h av i o r see m s super i o r t o m o d e l i n g . D A L s c he d u l e s p r o v i d e p re c i s e c o n t r o l by red uc i n g , but n ot e l i m i n a t i n g , s o m e b e h av i ors . D ou b l e- b l i n d p roced ures a l l ow m o re o bj e ct i ve eva luat i o n of p ro g r a m s by e l i m i n ati n g o bserver b i as .

PSI: A n Applica tion for College Classroo111s W h ile the SQR3 method utilized by Fox (reviewed in Chapter 6) represented an extension of o perant princ iples into the college environment, it d i d not provi d e a blueprint for a college instructor t o u se in develo p i n g a learn ing-theory-based classroom . Such a blueprint has been d evelo p e d by Fred Keller . While the essen ti als of the " Keller Plan , " or personal ized system of instruction (PSI) , were first proposed in 1963 (Keller in Ulrich , S tach n ik, and M ab ry, 1 966) , h is first report of its u se to have a m aj or impact on h igher education was the p ivotal paper, " G oo d bye teacher . . . " ( 1 968) , wh ich appeared in the first vol ume o f t h e Journal of Applied Behavior Analysis. Keller argued that the goal of e d ucation sho uld be for students to learn all that they were capable of learn in g in a s ubj ect area . Conventional gra d i n g systems, however, by lim i t in g the time ava ilable for a s tu d en t t o s t u d y the material, cause fas t s tu den ts to learn a great deal and slow s tu den ts to learn m uch l ess . Keller s uggested that time requ irements, rather th an grades, should b e the variable element in h i gher e d ucation . Therefore, he divided h is courses up into self-con ta ined segments, or learn i n g m o d ules . The studen t was req u ired to d emonstrate mastery of the con tent of a particular module, as m easured by a q u iz, before advanc i n g to the n ext m o dule. By the end of the course (which occurred at d i fferent times for d i fferent studen ts) , all stu d ents had learned the essent ials of a s ubj ect are a . S ince a class composed of s tu d en ts studying d ifferent segments made conventional lectures i mpractical, students stud ied the modular mater ials wh ile alone or w i th the a id of tutors . The tutors, u sually advanced students, gave m odule qu izzes to those s tu d ents who felt that they had mas tered the content of the module . Some psycholo g is ts have embraced the i dea of replaci n g gra d es en tirely w i th mastery criteria. Hergenhahn ( 1 976) maintains th at studen ts in PSI classes prefer them to conventional lecture classes, and that professors using PSI u sually con tinu e to u se i t . S ince , by the definition of mastery criteria, the studen t m ust learn the material in one module at the A or B level to pro gress to the next m od ule, m ore students master course con tent in PSI classes . The self- pacing features of PSI , however, can often be d etrimental to the work o u tp u t o f stu­ dents with m in imal self-moti vation . Often the ra te of m o d ule completion is very low early in an acad e m ic time un i t . Bufford ( 1 976) h as i n trod uced a b on u s system for h igh rates of module completion early i n the semester . He reports 2 . 4 modules completed p er week in the bonus con d ition an d only . 96 mod ules completed d urin g b aseline weeks . The a uthor, who has used s uch a front­ loading b on u s sys tem in several o f h is partially self- paced con tingency-

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managemen t- based courses, has fo und th is system to be effective in getting students off to a good start in the courses . These systems employ a d ifferen tial re inforcement of h igh levels (DRH) schedule in m o d ified form . Some college a d m in is tra t ions have been able to accommodate themselves to the indefin ite time l im its for course compl e t ion that self- pac ing imposes . Col­ lege IV o f G rand Valley U ni versity in Allen d a le, M ich igan u se s only PSI . A professor who taught there for several years h as reported to the au thor o verall satis faction w ith PSI in com parison to conven t ional " grade/lecture/fixed time lim it" teachi n g metho d s . Supervisin g s tu den ts who are com pl e t in g their courses at many d ifferen t t imes, however, can be an a d m in istra tive n i gh tmare. The au thor's u n iversity has a pol icy of t ightly lim it in g the durations o f inco m­ plete s ; the PSI course in introductory p sycholo gy is m od ified by requ iring stu­ dents to fin ish w ithi n one semester . Because of the schedul in g problems that self- pacing creates, most PSI courses rep orted in the curren t l iterature h ave only l im ited self- pacing and employ various techn iq u es (such as front loading and the doom sday contingenc ies previously mentioned in th is chap ter) to speed up student pro gress . D uNann and Fernald ( 1976) u sed a doomsday contin gency and found a sign ificant preference for the PSI approach u sed in one half of an intro d uctory p sycholo gy course to the convention al lectu re approach used dur­ i n g the o ther h alf. Obj ective qu iz scores were also s ign ifican tly h igher with PSI . The authors followed u p stu dent retention of course materials after two years (a noteworthy and rare event in the l iterature) and found that stu dents w ith low and m e d iu m G PAs retained sign ificantly m ore of the material learn ed d uring the PSI cond it ion (DuNann and Weber, 1976) . Stu dents with h igh GPAs d id not benefit from PSI , wh ich is in agreement w ith S altz's conten tion (Chapter 1 1 ) that h igh in tell igence is related to the ability to learn u n d er un programmed con d it ions . O ther factors which have worked again s t incorporation of the PSI concept in most college classrooms include the fin anci al and eth ical issues related to using a d vanced s tu d ents as tutors and the preference of n1 any s tudents for lectu res rather th an ind ivi d ualized s tud y . G ivin g cou rse credit to s tudents for being tu tors ra ises the question of wh ich learning experiences should legitim ately count towards a degree . Payin g tu tors tends to ra ise the relative cost of PSI co urses and re duces ad m i n is trative enthusiasm . Many s tuden ts feel enti tled to lectu res in return for the ir tu ition . Some have told me th at if they wanted to read text material on the ir own, they could h ave done that at hon1 e wi thout the expense and e ffort of attend ing college . Keller's vision of the professor as con ­ tin gency manager ra ther than teacher would see n1 n1ost appealing to those pro­ fessors whose lectu re skills g i ve them and the ir s tu d ents less than adequate ra tes of re inforcement. While neither the fixed aca dem ic time unit nor the lecture - a n d - d iscu ssion method of teach ing see m li kely to van ish , n1 any college classro oms are still slated to experience the mach inations o f the con tin gency manager . Keller's pior,eering work has opened the way to a variety of increas ingly soph is ticated applications of contingency managem ent tech n iq u e s . Miller and Weaver ( 1976) have progresse d beyond the s tu dy gu ides developed by Keller and the PSI

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m ovements to programm e d workbooks wh ich use d iscri m in a ti on trainin g tec h ­ n i q u e s to teach complex concepts . Using prompts (clues) w hich are gra d ually fad ed out, these workbooks are reported to produce superior performance on o bj ective tests compared to the s tu dy of conven tional textbooks . The fad ing o u t of prompts i s designed t o reduce the a versive effects o f m is takes . The i d ea o f teach in g b y h avin g the learner d iscri m in ate relevant from irreleva n t examples o f the concep t (negative informa tion) i s derived from t h e operan t m o d e l o f concept form ation . Kell er's u se of s tu den ts to help man age a course h as also l ed to a variety o f application s . The au thor once u sed volun teer superior s tudents as Behavioral Technic ian s (Behav-a-Techs) in a proj ect a t Occiden tal C ollege to i m prove the d is tribution o f commen ts in d iscu ssion grou ps (Swen son , 1973) . H i ghly vocal students (who were n a ive to the g oals of the Behav-a-Techs) were p u t on a DRL (differential reinforcemen ts of low levels) sche d ule, and silent s tu den ts received social and nonverbal reinforcem en t (in tense a ttention, smiles) for any com­ ments . The increased rates o f p articipation o f the formerly silent students were maintained d uring the b aselin e 2 measure m en t p eriod . The suppression of talk­ in g out in the h i ghly verbal s tu dents, however, gradually dissipated with the removal of aversive consequences (inattention , foot s h u ffling, y awns) for talk in g o u t m ore than once per 10-m inu te time p erio d . Stud en t ratings o f t heir satisfac­ tion with the experimental d iscussion groups were superior to ratin gs o f control d iscu ssion group s . While the proj ect j ust d iscussed was a d m ittedly man ipul ative , t h e en d re­ sult was a freer classroom environment in which con trol o f discussion by a few stu dents was m i n i mized to the benefit of shyer s tu dents . The a u t hor's b ias is that u se of the techniques of contingency m an agement in the college classroo m is j ustified if such use is carefully thoug h t o u t a n d designed with sen sitivity to the n eeds of s tu d en ts rather than simply the conven ience of professors . Expl an a ­ t ions t o s tu d en ts who h ave concerns abou t use o f s uch tech n i q u es, of what is being done an d why , may not only reduce the a versive q u alities of these tech ­ niques b u t m ay also be a means to teach learn i n g p rinciples . A we l l - k nown co l l e g e- l ev e l a p p l i c at i o n i s t he "perso n a l i zed syst e m of i n st ruc­ t i o n" ( PS I ) a p p ro a c h , w h i c h m a ke s g rad e s c o n t i n g en t u p o n a m ou n t l ea r n ed w i t h un l i m i ted t i m e. Ti m e c o n st ra i n ts i n m a n y c o l l eg es h a v e resu lted i n m o d ­ i f i cati o n s, a n d n ew tec h n i ques , suc h a s rewa rd i n g e a r l y p ro g ress with f ro nt­ l o ad i n g b o nuses and d o o m sd ay ( f lun k i n g ) c o n t i n g e nc i es fo r l a g g a rd s, h av e b e e n ad d ed . Fad i n g out o f p ro m pts h as a l so been succ es sful i n co l l e g e- l evel i n s t ruct i o n a l m ateri a l s .

Clinical Applica tions As we stated in the beginning of th is chap ter, m os t applications o f operan t con d i tioning tec h n iq u es in clin ical psychology involved the u se o f token econ ­ o m ies with large n u m b ers o f institutionalized psychotic s . Hall , Baker, and H u tchinson (1977) , worki ng w i th chron ic schizophrenic pati en ts, compared two control groups w i th a token economy gro u p . They found t h at the token p a ti en ts

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d ecreased their o utpu ts of three types of unwan ted behavi ors compared to both no- trea tn1 ent con trols and no-token , contin gen t social rein forc em ent control s . The patien ts who were most deteriora ted in itially were the ones who demon­ strated the greates t g a ins . Some patien ts, however, increased their em ission s o f non target b ehaviors, which m ay demonstrate a p aradoxical o r behavioral con ­ trast effec t . The treatment was con ti n u ed for 1 5 m onth s . At the en d o f t h a t time, the con tin gen t social reinforc em en t control gro u p had caug h t up w ith the token group . Part o f the reason the token p atien ts d i d not m ain tain their early, most improved status was reported to have b een b ecause of the attitu d es and expecta­ tions of the ward n urses dispensing the tokens . Over t i m e, the extra work entailed in noting beh avi ors an d dis tri b u ting tokens may have made the re­ sponse cost o f the program too h igh for the n urses to concen trate on m ain taining it. The m ain tain ing of staff effic iency h as been the s ubj ect o f operant beh avi oral modifica tion techniq u es . Iwata and colleagues (1976) conducted two exp eri­ ments on four u n i ts of a residen tial fac ility for mul tiply h a n d icapped retarded persons . Atten d an ts in the exp erimental condi tion meeting s p ecific perform ance cri teria becam e eligible for a lottery . The prize for winning the lottery was the opportun ity to choose their d ays off for the following week . The control con d i­ tion used specified staff assignments . Attendan ts partic ipa ted in both the con d i­ tions at different phases o f the stu d y . A m ultiple baselin e replication s howed that the lottery techn iq u e was indeed an effective way to m ain tain h igh levels of staff perform ance. While the tok en economy is the most effic ient way to modify the b eh avi ors o f large numbers o f patients, primary reinforcers can be u sed to good advan tage with i n d ivi dual psychotic patien ts . An unusual aversive reinforcer was em ­ ployed by Fichter and colleagues ( 1 976) , who allowed a chronic schizophrenic patient to escape "nagging" by em ission of s p ecified target beh avi ors (clear speaking and placing arm s and elbows on the arn1 res ts of h is chair ra ther than making strange gestures with them) . With time, the patient learn ed to attend to the S 0s for emission of the target behaviors and so was able to avoid the "nag­ ging" entirely . During baseline 2 , the clear-s peaking b eh avior was maintai ned , b u t arm and elbow placen1 en ts were not . Th is sugges ts that s peaking was an exam ple of functional behavior ( b ehavior which creates i ts own rein forc e­ ments) , wh ile arm and elbow placements w ere n1a i n ta ined only by the experi­ mental contingenc ies . Al tho ugh most applications o f o p eran t techn iq ues have been concentrated in institutional settings, the modeling proced u re d eveloped by Band ura (Chap­ ter 9) has been found useful by indivi d ual n1 ental health workers for treati ng neurotic or anxious clients . H orn e and M a tson ( 1 977) con1 pared modelin g , d e­ sensitization , flood ing, stu dy grou ps, and control groups as procedures to re­ duce test anxiety in college studen ts . The n1odeling proced ure consis ted o f lis teni ng t o tapes of students, who expressed considerable test anxiety i n the first tape, and progressively less anxiety in subseq u ent ta pes . On the Tes t Anx­ ie ty Sc a l e, it was fo und tha t modeling was the most effective tec h n i q u e, fol­ lowed by desensi tization , floo d ing, study skills, and no treatmen t . M easu res of

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pulse rate s howe d desensitization to have produced the lowes t pulse rates, and examin ations of fin al course grades fou n d desensitization-gro up students to do best, followed by m o deling-gro u p s tu d ents, s tu dy-s k ills s tu dents, flood ing­ gro u p s tu dents an d con trols . While these resul ts d o not clearly show modeling to be more effective than the techniques of desensitization and flo o d in g d erived from classical con d itioning, they do su gges t tha t i t may b e a u sefu l addition to such tech n i q u es . Rosen thal, H u n g , and Kelley ( 1977) compared two types o f modeling p roce­ d ures . They fou n d that when the therapis t was " b usinesslike, " as opposed to " warm , " the clients were m ore successfu l in approach ing feared obj ects an d reported less fear. This typ e o f research illustrates the p rocess of exam in ing the details of a p roced u re in an attempt to determi n e the most e fficien t an d effective ways to con d u ct s u ch therap ies . This is a necessary an d m uch-neglected s tep in m aking the methods of psychological intervention more p recise and powerfu l . The biofeedback procedure, t o b e reviewed next, h as been the s u bj ect of such a detailed examination, an d this, as we s h all see, has resulted in the d iscarding o f n a ive hopes . C o n t i n g e n cy m a n a g e m e n t a p p ro a c hes h av e been effe ctive i n i m p rovi n g b e­ h av i o rs o f b o t h staff a nd pat i e n ts i n m e n t a l i n s t i tuti o n s . Wi t h b ri g h t , a n x i ous c l i e n ts, m o d e l i n g p ro c e d u res a l so w o r k w e l l-es p eci a l l y i f t he m o d e l acts i n a bus i n essl i ke m a n n e r .

Biofeedb a ck David S h ap iro, one o f the p ioneers in the development of b iofeedback, defines biofeedback as " the application o f o p erant con ditioning m ethods in the control of visceral so m atomotor, or central n ervous s ys tem functions" ( 1977, p . 15) . The most com mon p roced ure is to amplify t he weak electrical sign a l s associ ated with a body fu nction an d then to use the amplified signal to drive an a u d i tory or visual d isplay. B ecau se the d is play tells people when they are s ucceeding, which most people fin d reinforci n g , the probabili ty o f em ittin g similar ( d esired) b e ­ h aviors i ncrease s . A s previously d iscussed , the success of the R u ssian psychologists in demon­ s tratin g that the autonom ic n ervous sys tem controlling the viscera could be con d itioned led to the efforts of M iller an d D iCara ( 1967) to use operan t con d i ­ tioning procedures o n b e h aviors con trolled by the autono m ic n ervous s ys tem . M iller's an d DiC ara's demonstration of the self-regulation o f what h a d been assumed to be automatic processes sugges ted a wide range of therapeutic appli­ cations of the new technolo gies . A clear statemen t of three obj ectives of b iofeedback research relevan t to therap ists can be fou n d in the 1 976-1 977 Aldine ann u al , Biofeedback and Self­

Control: 1 . the determ i n a t i on of the de gree to w h ich b iofeedback a i ds in learn ing i n ­ creased control o f physiological processes i n healthy i nd ivid u als , u n d er a vari e ty of experimental cond i tions that norm ally affects such processes (e . g . , environ men tal stress; i n d uced expectation s; . . . )

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2. the enhancement of the cure , managemen t, or prevention of various psycho­ logical and physiological d i sord ers throu g h b iofeedback - a i ded learn in g , in­ clu di n g those disorders presumed to be genera te d by envi ronmen tal s tresses as well as those crea ted by s pecific p hysi ological dysfunctions (as exempl ifi e d i n t h e cases o f ep ilepsy and s troke) 3 . the enhancement of increased awareness . . . [Kamiya et al . , 1977, xv-xvi]

The poten tial importance of the developmen t of b e havi oral technologies for con trolli n g b o dy s tates is related to the dram atic s hift in d isease pattern s in Wes tern countries over the past 150 years . While com m u n icable diseases once were the leading causes of sickness, tod ay s tress-related an d degenerative d isor­ ders predom inate . Med ical practices derived from the m e d ical ass u m pt ion that sickness is cause d by specific agen ts, such as particular m icrobes or tumors, h ave b een spectacularly successful against com m u n icable d iseases . This crisis ­ oriented " m edical model" has been m uch less s uccessfu l against he art d iseases, u lcers, arthritis, a n d other stress -related disease s . Evi d ence is acc u mulating that a person' s reactions to s tress may be the most critical factor in these disorders . Holmes and Rahe ( 1967) have collected data whic h suggests that s tress­ provoking life changes are more relate d to a w i de ran ge of illnesses ( incl u d i n g colds an d tuberculosis) than tra d itional causes, such a s ch ill ing and exposure to germ s . Because a person's pattern of responding to s t i:ess on a p hysiological level can be altered through bi ofeedback training, such training may become increasingly important in maintaining or regain i n g health . As we shall see , however, many problems s till m ust be solved before b iofeed back can reach i ts full potential as a means for coping with s tress an d hence maintaining heal t h . S o m e of the issues and problems th at m ust be deal t w i t h before biofee dback tech n i q u e s become adequ a te to reduce sign i fican tly the incidence of s tress ­ related d iseases have been reviewed by S h apiro (1977) i n h is presidential ad­ dress to t he Society for Psychological Research . These inclu de : (1) the extent to whic h nonbiofee dback self-control procedures such as n1 e d i tation can s upple­ men t biofeedback or replace i t, (2) the effects of i n s tructions and o ther cogni tive elements in determ ining the s uccess of b iofeedback proced ures, ( 3) the n1 ainte­ nance of the changed behavior under s tress and o u tside of the bi ofeed back training area, an d (4) wh ich techniques are e ffective and w h ich are of n1 inin1al effectiveness . Woolfolk and colleagues (1 976) fo und n1 ed i tati on to be eq ual to progressive (Jacobson) relaxation and both to be s u perior to no treatm ent in treating insom­ nia. H arris and colleagues (1 976) found that learn ing of breath ing exercises ( placed respiration) reduced au tono n1 ic reactivity to real and an ticipated aver­ sive events . Atten tion to and con trol o f breathi n g is an im portan t part o f many types of meditative exercises, inclu ding Za zen ( Zen) m e d i tation . Schandler a n d Grings ( 1 976) found both progressive relaxation a n d tactile feed back (vibrating stimul us) to be s uperior to the n1ore normally employe d visual or a u di tory feedback n1 o des for red ucing the electromyograph ic ( EM C or electrical muscle potential) response to s tress . These results suggest that further refinement of b iofeedback tech nology is needed before it can be considered clearly s uperior to e q u i pmen tless methods for the treatn1 en t of gen eral tension .

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The research on the effects of instructions further s hows the extent to which factors o t her than b i o feedback can alter physiolo gical functioning . These effects can be fairly complex . S hapiro ( 1977) reported that subj ects instructed to alter p almar ( hand) swea tin g were unable to do so . W hen they were instructed to i ncrease heart rate, however, not only were they able to ach ieve as m uc h control as subj ects given feedback, b u t their palmar sweatin g also changed in consistent d irections ! Bouchard and G ranger ( 1 977) have reported sim ilar results for heart rate slowing. They fou n d no d ifference between s ubj ects given instructions alone and subj ects experienci n g instructions i n combination with feedback. Fee dback may b e superfluous in control o f heart rate, but the same does not seem true for blo o d pressure . S ubj ects g iven feedback w i thou t instructions to control blood press ure were much less effective in increasing blood pressure than subj ects given instructions and feedback, b u t the two groups d i d not d iffer in their abilities to reduce blood pressu re . Subj ects g i ven only instructions were inferior in their abili ty to increase bloo d pressure b u t equal in their abilities to decrease mean systol ic pressure . These results b o th show that cogni ti ve - verbal variables may o perate to d ifferent extents with d ifferent p hysiological m easures, an d that b iofee dback is not j ust an autom �tic, m ec h an ical cond itioni n g process . O ne o f the most important q uestions i n b io feedback is the extent to whic h the n ewly trai n e d "relaxation-relate d " responses can b e m a in tained und er s tress ful con d itions . One o f the early p hysiolog ical responses to b e m o dified was the EEG (electroencephalography) or b rain wave respon se . I t was fou n d that m o s t persons could learn to p ro duce more alp h a rhythms (8-13 H z waves) i f they were g iven feedback when pro ducing such waves a n d that they reported feeling tranq u il when producing them . Kamiya a n d colleagues (1977) have note d , however, that alpha may be controlled more by such factors as no t look­ ing for afterimages with closed eyes than by the electronic feedback . This $ug­ gests that producing alp h a is not m uch d ifferen t from j ust tryin g to feel relax e d . M oreover, C hisholm , DeGood, an d H artz (1977) exam i n e d subj ects' abilities to stay relaxed d uring aversive ( s hock) situations in their laboratory after alp ha b io feedback train ing . They fo u n d tha t alt ho u g h m an y p articipan ts could con­ tinue to pro duce alp h a rhythm s d u ri n g the s tress session s , the heart rates o f these participants were elevated and they rep orte d themselves as b e i n g as tense as control subj ec t s . A no t her p hysiolo gical response t h a t h a s been exten s ively i nvestigated in t he hope of p roduc in g long-lasti n g relaxation states is t he EMG or elec tromyograph ic response . The EMG is a measure of a m u scle's rea d iness to constrict, and i t was hoped that by reducing m u scle arousal , tension (muscle tightness) hea d aches an d general feelings of tenseness coul d be alleviated . Recordi n g electrodes are u s u ally placed over the frontalis m uscle o f t he forehe a d . The frontalis has b een s hown to pro d uce tension headaches when overcontracte d (Epstein and Abel, 1977) . H owever, Epstein and Abel ( 1977) reported that while i ncreased EMGs i n the frontalis m u scle were related t o increased reports o f hea d ac hes, s uccessful d ecreases in E M G s were o ften not related to decreases in headache s . S trangely enough, three o f the six patien ts had less headaches following the b i o feedback treatments and m aintained these gains after 18 months . W hen the E M G s o f t he b io fee d b ack patients were checked several months after t he ir training, no evi -

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dence of con tinued self-control o f muscle activi ty was fo und . Therefore, the improvemen ts of the three patients may represent placebo effects . A placebo is an inert substance or control treatment given to s u bj ects to make them think that they are getting treatment. Further evi d ence that frontalis EMC biofeedback is ineffectual in producing generalized states of relaxation has been provid ed by S he d i vy and Kleinman ( 1977) . They found that bi ofee d back-pro duced red uc­ tions of EMC intensity of the fron tal is m u scle did not generalize to EMC reduc­ tions in o ther m u scle group s . C hesney an d S helton ( 1 976) h ave even reported EMC biofeed back to be less effective than Jacobson relaxation exercises . If b o th alph a and EMC bi ofeedback h ave failed to live up to the early hop es of biofeedback enthusiasts, is there an y biofeedback procedure useful in pro­ ducing lasting resistance to s tress effects in the outside environment? H u tchings and R e inking ( 1976) h ave reported that EM C biofeedback in com bina tion with J acob son progressive relaxation exercises or with a u togenic training ( practicing feeling the hands as heavy an d warm) works better than relax ation exercises used alone . Training in red ucing blood pressure of esse ntial hypertensive clients has been reported not only to result in con tinued lower blood pressure u n d er s tress in an d o u t of the laboratory b u t also to h ave been relate d to better perfor­ mance on the category test whic h measures cogni tive functioning (Kleinman and colleagues, 1977) . S hap iro (1977) has suggested com b i n in g biofeedback with systematic desensi tization of probable stress -a�ousing situa tions and stimul i . He advocates h avi ng feedback training carried o u t i n stim ulating or s tressful laboratory cond itions to prep are the person for dealing with a stimulat­ ing and s tressful ou tside environmen t . He reports s uccess in using s uch an ap proach wi th the heart rate response . Many of h is subjects actually learned to reduce the ir heart rates when an ticip ating an d experiencing shock ! To conclude this d iscussion o f the effectiveness of bi ofeedback proced ures in deal ing with stressful situ ations, i t seems that some treatments that were favored early in the h is tory of biofeed back, such as alph a wave tra in ing and fron talis EMC training, do not produce suffic ien t lasting benefits, used alone, to j ustify their continued clinical u se . S till be ing investigated are con1 binations of EMC training with o ther relaxation proced ures and training of the cardiovascular res ponses (heart rate and blood press ure) . As the search for procedures related to general resis tance to s tress and ten ­ sion continues, much o f the n1 ost exciting research in biofeedback involves chan ging more specific responses . Wh i tehead, Renault, and C oldiamond ( 1975) were a ble to train fo ur normal won1 en to control the ir rates o f stomach gastric acid secre tion with con1 binations o f visual fee dback and money. When money was n1 ade con tingen t upon increased secretion in a differen tial rei n forcement o f high ra tes (DRH) schedule, secretions increased to three times that o f the base rates . When the sche d uling was changed to a d i fferential reinforcement o f o ther be haviors (DRO) sched ule, secretion rates returned to basel ine levels . It is of in terest that o ther physiological parameters, such as increased EM Cs, respira­ tion rates, and heart rates, d id not always change in a systematic relationship to secretion rates . As in many o ther stu dies, subj ects differed in the ir abilities to control the selected response through biofeedb ack . These procedures may so me day lead to biofeed back treatments for peptic and gastric ulcers .

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N o t only the classic psychosom atic illnesses, such as u lcers, are related to s tress . The i ncidence of ep ilep tic seizures is also s tress related (Small, 1973) . L u bar an d B ahler ( 1 976) used b iofeedback to train eight severely ep i lep tic pa­ tients to i ncrease their output of 12-14 Hz EEG sen sorimotor rhythm s . This sensorim otor rhythm (SMR) is pro duced from t he sensory-m o tor or central fis ­ s ure area o f the cereb ral cortex and i s a ssumed t o i n hi b i t m o tor activity. I t was exp ected that i ncreased SMR would i n h i b i t the m ot or activi ty causing convu l ­ sions a s well as seizures i n general . Patients were also tra ined to i n h i b i t theta (4-7 Hz) and ep ileptiform spike activity. Training consisted of three 40-m i nute sessions p er week . B aseline measures were collected , and the half of t he cortex whose output was to trigger feedback was alternated to let the EEG of the other hemisphere serve as a "within-s u bj ect con trol . " Two patien ts beca m e free of seizures for months at a time, and most of t he other patients had reduced seizure incidents and reduced n eed for anticonvuls an t medication . W hen patien ts left training to go on vacation , the n u m b ers of rep orted seizures gradually i n ­ creased . The authors noted that switc h i n g t o noncontingent (pseudofeed back) reinforcement also led to an increase in seizure s . These results suggest that biofeedback is a u seful s upplement to m e d ication, espec ially for epilepsi es wi th m o tor involvements . J u s t as in most b e havioral modification app l ications, how­ ever, t he gains extinguish when the program is s u sp end e d . To be fair, the m u scle tone acq uired through exercise also "extinguis hes" w hen a college pro­ fessor or s tu d en t becomes excessively d eskbo u n d and "suspends h is exercise program . " The hope of fin d in g extinction-free therapeutic methods may be a holdover from beliefs i n the medical m o del, whic h assume that there exists a specific cause for each d isease and that removal of this cause cures the patien t . O n e way t o make sense of the varyin g effectiveness of different b iofeedback m ethods with d ifferent stress-related d isorders is to ass u m e that the m ore " new" information the feed back provid es to the u ser, the m ore l ikely the training is to be effective . S i nce the average person has considerable i n formation about h is general states of relaxation, simple procedures for i ncreasing relaxation thro u g h bi ofeedback h ave been of lim ited effectiveness . Most ulcer o r epileptic patien ts, however, would b e assumed to be u nable to d iscrim inate physiological c hanges related to gastric acid secretion or output levels of sensorimotor EEG rhythm s . H ence, b iofeedback training would b e exp ected t o b e most beneficial with such patien t s . M an y responses, however, are d iscrim inable by some i n d ivi d u als and not by other s . Kaplan ( 1975) h as s uggested that m ales who suffer fro m premature ej aculation during sexual intercourse do so because they are u nable to d iscri m i ­ nate accurately the subtle cues which d is tingu ish the stage of sexual aro usal (pl ateau s tage) from the stage of " ej aculatory i nevitab i l i ty . " Support for this theory h a s come fro m the work of R osen , S hap iro , and Schwarz (1975) and Kantorowitz (1977) who succeeded i n treating premature ej aculation by provid ­ ing prec ise feedback o n penile d iameter, which i s closely correlated t o the level of sexual aro u sal . W hen provided with feedback, most s u bj ects were able to l earn to m aintain arousal at the plateau stage for as long as d esire d . Like many sexual d i fficulties, this typ e of dysfu nction m ay not only be cau sed by s tress b u t m ay also prec ipi tate add itional s tress i n the s ufferer a n d h is cosufferers.

300

M odern Contenders

As the work o f R osen and colleagu es ( 1975) an d Kan torowitz (1977) demon­ s trates, the range of applications of operant control of i nternal s tates is wide, i ndeed . Sakai and Hartey (1973) were able to train m ale subj ects fir st to raise their fin ger temperatures and later to raise the temperatures o f their scrotums (testi­ cles) . In three of the five subj ects, the resulting tem p era ture rise was s u ffici en t to k ill all s perm . This experimen t suggests the possibil i ty of develop i n g behavi oral m e thods o f b irth control . ( I t woul d , of course, be essential for the male not to b ecome slack about h is daily temperatu re b io feedback exercises . ) Recen tly , E M G b i o feedback has b een extended i n to the tra d i tional m e d ical areas o f d e fi­ c i en t neuromuscular con trol . Ingl is, Campbell , and Donald ( 1976) h ave re­ viewed applications of EMG b i ofeedback in treating p eri pheral n erve m uscle damage, the effects o f s trokes (which k ill b rain cells by d epriving them of foo d an d oxygen), partial paralyses, a n d cereb ral palsy (early bra in damage havi n g a m otor component) . Noting that adequate control procedures to check for placebo effects are rare, they cite considerable evidence to s ugges t that p a ti en ts can learn to gain more control over the i nvol u n tary activi ty of volun tary m u s­ cles . This neuromuscular reeducation approach has b een successful i n restoring function to paralyzed limbs where som e n eural con trol rem a i n s or where neural control has b een rein troduced through transplan ting intact n erves which had formerly controlled o ther m uscles . Many patients were able to produce som e motor un it action poten tials in muscles which could n o t be con tracted on a volun tary basis . Within a couple of hours, those patients who had at least a few i n tact n erve end ings were producing s u fficient m o tor u n i t action potenti als fro m these surv i vi ng n erve endings to ach ieve large p ercentages of norm al , volu n tary m uscle functi oni n g . The various stu d i es reported p ercentages of patien ts who ben efi ted from such treatm ents from abou t 50 p ercen t to over 85 p ercen t . The basic technique also works for spas tic or overconstricted m u scles . Haggerty (1977) h as reported on the developmen t o f m i n iature sensortran s n1 i tter un i ts (d isgu ised as ladybugs) wh ich can be left affixed on the legs of children w i th cerebral p alsy and send wireless data about the levels o f muscle activi ty for prolonged time periods . Th is tech nology, which is a s p i no ff from the space program 's n eed for con tinuous b i o tel emetry, could provide a means for con ­ tinuous b i o feedback during norn1 al activi ties . Th is would be of s peci al b enefit in increasing the effectiven ess and practical i ty of long- term b iofeedback treat­ men t for epilepsy an d n euromuscular disorders . Not all the possible appl ica tions o f biofeedback involve treati ng patholog i ­ cal cond i tions . The tech n iq u es have also g i ven rise t o the dream o f increasing man's a b i l i ties and alterin g h is/her conscious n ess in benefic ial ways . S heer (1977) has reported that the 40- H z fas t-wave com ponent o f the EEG spectrum is related to memory consol ida tion . He has also reported tha t th is res ponse can b e increased thro ugh b i o feedback, o pen i n g the possib ility of increasing the ab i l i ty to memorize. Ormun d , Q uin tanell a, and Swenson (1 978) fo un d that while male colleg e s tuden ts i n i tially prod uced h igher average levels o f fast-wave EEG (which is pre s umed to be related to active cogn i tive function i ng) , after b i o feed­ back the fen1 ale s ubj ects were producing s uch waves a t the hi ghes t level . To sumn1 arize, although many of the earli er hopes for s uccess ful appl ication

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of b iofeedback h ave not been realized , the field is still developing and new a n d m ore sop h is ticated p rocedures are being develop e d . In addi tion , current re­ search makes clear that even proced ures develop e d from the o perant or Skinne­ rian tra d ition are strongly m o dified by cogni tive variables, although the extent to which s uch variables i nteract with the con d itioning variables is not the same for all p h ysiological measure s . This advances the development of unitheory by increasing our u n d erstan d i n g of how cogn i t ive and connection is t fac tors infl u­ ence each o ther and the types of situ ations in wh ich one or the o ther is most i mportan t . The common observation that d ifferent persons respond to traini n g p rocedures i n d i fferent ways may a dvance our knowledge of h o w p hysiological and con s titutional variables i nteract with learn ing variabl e s . For the future, w e m ay expect further soph ist icated use o f more opera n t principles . The u s e of complex schedules by Whi tehe a d and colleagues ( 1975) m ay be an early example of th is tendency . S tan dard b iofeedback practices w i ll be combined with o ther behavi oral mo dification tech niques, including those derived fro m Pavlovian principles, and this m ay help i ncrease our understand ­ i n g of the relationshi p between association learnin g and reinforcemen t learni n g . Because of the potential for therapeutic benefit, there will b e s trong i ncentives for the d evelopmen t of sophisticated b iofeedback devices that can be worn comfortably for long periods of tim e . As in the device develope d fro m space­ program b i o telemetry equ ipment described earlier, the new devices will be i n radio contact with their controlling computers an d fee dback d isplays (which m i g h t be skin vibrations) . This will eli m in ate the wires which tod ay clutter u p biofeed b ack clinics and laboratories a n d i nterfere w i th s u bj ects' m ovemen ts . As small computers b ecome less expensive, m ore work will be done on m o di fying p atterns of several physiol ogical processes a t one time, which will be a closer analogy to o ur n atural reactions to s tress and s tressors . This m ay elim in ate the problems of lack of generalizabi l i ty fro m laboratory to the o utsi d e world encoun­ tered in much b rain wave and E M G research . As the field matures, the uncriti­ cally enthusiastic and simplis tic views of b iofeedback will grad ually be d is ­ card e d , to be replaced b y real a n d reprod u c ibly durable results t h a t m ay nonetheless be significant and dramatic . B i ofeed b a c k refers to p ro v i d i n g a p ers o n w i t h e l ect ro n i ca l l y a m p l i f i ed i n fo r­ m at i o n a b out c h a n g e s i n p h ysi o l o g i c a l res p o n ses, such as b l oo d p ressu re o r b ra i n waves , t o a l l ow t h e p ers o n to e x e r c ise v o l u n t a ry c o n t ro l o f t h e res p o n s e . S i nce suc h c o n t ro l i s assu m ed to b e re i nf o rc i n g , t h i s d e m on s t rates o pe ra n t l ea r n i n g o f i n n e r res p o n s e s . B i ofeed b a c k , w h i c h m ay b e i n f lue n ced b y c o g n i ­ t iv e v a ri a b l es suc h a s i n st ruc t i o n a l set, h as not been f ou n d t o be m o re effec­ t i ve t h a n re l a x at i o n t e c h n i ques for re l i ef of s t ress . It s ee m s m ost b e n ef i c i a l w hen n atura l fee d b a c k is m i n i m a l .

Chapter Perspective

O u t of the unlikely womb of the Skinner box has come a rich plethora of ways to p u t psyc hology to work in the "real" (that is, everywhere but on college cam ­ p u ses) worl d . Because the tra d itions of the laboratory inclu de observance of

3 02

J\ l odern C o n t e n ders

methodological considerations which p rovide a basis for critical evaluations of me thods, and because operan t theory is s traightforward eno u g h to be reduced to form u las comprehensible to those w ho would develop and use applications, the methods h ave been widely tes ted . Through this tes tin g, t hese m e thods seem to be evolving towards greater effectivenes s . Yet, iron ically, for a l l the inventiveness of the ever-i ncreasing hoards o f operant applicators, the n e t effect of these applications has been t o call into q u estion the basic mechan istic assum ptions of the conn ectionist approach to learn in g . The renewed legitim acy of cogn itive variables bears witness to this fact . We are now faced with the p aradox that the critical debate over the pro­ cesses involved in classical an d instrum ental con d i tioning, together with t he contin ued demonstrations of the success of applying operant principles, sug­ gests that we are becom ing more an d m ore successful in using tools whose mech an isms we u n d erstand less an d less . Since connectionist theory seems to be evolvin g towards the cogn itive viewpoint, let u s now exam ine what that cogni­ tive viewpoint is today. Key Terms accountabil ity

front load ing

prompt

ba cku p system

full-session DRL method

,response cost

fu nctional beha vior

re versal design

be havioral obj ectives

i nterval method

charting

multiple base l i ne

spaced re spond ing D R L method

change agent

neuromuscu lar reed uca­ tion

base lines

1

and 2

conse q uation contingency management double blind focal ind ividual method

specification time sampl ing

observation

token cost

operational defini tion

tria d ic mo del

personal ized syste m of in­ struction ( PSI)

An notated Bibliography

Because of the vast number of ava ilable so urces on operant ap plications of learni ng theory, I will only reco n1mend one book; R . Mallot, Con ting ency m a n ­ age m e n t in e d u c a tion ; O r I ' v e g o t b lis ters on m y so u l a n d o th e r e q u a l ly ex citing

rev . e d . (Kalamazoo , M i . : Behaviordelia, 1 974) . This tex t is partly a comic book with progra n1 111ed learni ng ma terials and n1 uch n1ore . The best way to get prin1ary access to the li tera ture would be to scan recent issues of the fol lowing j o urnals : ( 1 ) J o u rn a l of A p p lie d B e h a vior A n a lysis, w i th applications to education , industry , personal habits, corrective institutions, and m iscellaneous social in­ stitutions, ( 2) B e h a v ior Resea rch a n d Th e ra p y, or B RA T, whic h focu ses on clin ical applications, as do (3) B e h a vior Th era p y , and (4) Jo u rn a l of B e h a vio r Th era p y a n d E xp erim e n t a l Psy c h ia t ry ; for those in terested in biofeedback, I strongly recom-

p la c es,

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m en d (5) Psychoph ysiology. (Another good gu i d e to curren t trends in bio feed­ b ack is the Aldine ann u al p u bl ication , Biofee db a ck and self- control. ) APPE NDIX TO CHAPTE R

10

Timing Tape Techniques for Use in Observing B ehaviors

To m ake a tim ing tape to tell you when to observe behavi or on a variable interval sche dule, first select some reasonable length of tim e , such as 10 m in u tes, as your mean tim e in terval . Then print a series o f n um bers beginn ing 50 p ercent below your mean or d e fin i n g number and con tin u in g u p to 50 p ercent above that number. I n the followi n g 10-minu te exam ple, you would p ri n t the numbers 5 thro u g h 15 on slips o f p ap er . Place the n u m b ers in a container and write eac h n u m b er a s you d raw i t . Replace each n u m b er b e fore d rawing the next num ber. Conti n u e until the s um of the n u m b ers (or m in u tes) adds up to the total time allowed for observa tions . You will now n eed a cassette recorder and a watch . Lookin g a t your l is t o f n umbers and the watc h , say, " Begi n , " i n to the m icro­ p hone of the recorder (wh ich should b e recording) , and time the i nterval of the first n u m b er on your list. When the m in utes elapsed m a tc h the first n u m b er (as 6 m in u tes for t he number 6) , say, "Observe, " i n to your m icrophon e . Then time the interval o f the second n u m b er on your list, a ga in s ayin g , " O b serv e , " a t the end of the interval. Conti n u e until you have time d i ntervals corresponding to all the num bers on the l is t . A long - p laying cassette used on b o th sides will record 2 hours of this variable interval schedule. This t im in g tape tech n iq u e can also b e u sed for fixed interval schedule s . I n this case, sim ply say, "Ob serve , " at i nter­ vals correspon d i n g to your d e fin i n g number (such as 5 - m i n u te intervals for FI-5 ' schedule) .

M od e r n T h e o r i es w i t h a C o g n i t ive E m p h as i s

The cogn itive approaches w e w ill exam in e i n th is chapter deal w i th the forma­ tion of concepts and how these concepts change w i th i ncreasing maturity, the processes of language and memory, and selective factors in p aying attention . In many w ays, these topics seem both m ore complicated and more focused on h uman behavior than those of the connectionist approaches previ o u sly d iscussed . As we saw i n C hapters 8 anc;l 9, many connectionist theorists h ave s u g­ gested m o d ifyi n g trad i t ional a pproache s to understan d i n g con d i t i on i n g by i n­ corporating cogn itive and b i ological variables . The f9ur viewpoints we w ill review in th is chap ter represen t d i fferent types of cogn i tive approaches in a purer form . The last three of these approaches, w h ich incorporate biological variables, are similar in some w ays to recent views of i n s trumental learn in g and classical con d i tion i n g . The four viewpoi nts represen t the follow ing branches of the cogni tive approach : (1) concept form a t i on and verb al learn i n g ( Saltz), (2) psychol i n gu istics (C ho n1 sky) , (3) developmental-cogn i tive ( Pi age t) , and (4) i n ­ form ation processi n g ( N orn1 an) . The first secti on of th is chapter is organized around the concept-learn i n g theory of El i Sal tz , wh ich represents a tren d towards assi n1 ilati n g so n1 e aspects of behavioris n1 w i th the type of cogn it ive theori es d iscussed in Chapter 5 . In its eclecticis 1n and its concentration on verbal learn ing, this approach is indebted to the functional ist tra d i t i on . Saltz and the o ther concept-learn ing researchers re­ viewed in this section are pro d ucts of the American ex peri n1 ental ist­ environ mentalist b i as, much as Tolman was . The ir a tt e n1pts to explore the inter­ relation s h i ps of con d i tion i ng and cogn i tive learn ing are representa tive of modern learn i n g theory's " m i ddle grou nd . " I t is i nstructive to compare Saltz, who i den tifie s hi mself a s a cogn i t i ve theoris t, w i th Bandu ra , who identifies h i n1 sel f as a behavioris t (and w ho also re presents the trend towards convergence of the cogni tive and behavioristic viewpoi nts) . Bandura incorpora tes n1any cogn itive variables in h is theory but avoids detailed descriptions of cogn i t ive en ti ties . Sal tz is less t i m i d in speculat­ i n g about even ts pre s u n1ed to be happen ing w i th in the heads of his s u bj ec t s . The second theoretical viewpoint, by C hom sky, also strongly rej ects s t i n1 tilus-res ponse ex plana tions of learn i n g . He sees no need, however, to make any ex plora tions of con d i tion i n g nor to concede any points to beh avi orism .

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305

While S altz focuses on h u m an verbal learn in g, Chom sky's system deals with l ingu istic (langu age) behavior in general an d w i th the implications o f how h u ­ m a n s s tructu re their commu n ications . L i ke Saltz , C homsky speculates about the structure of cogn i tion s . Unl i ke S altz, Chomsky p os tulates that i n n ate an d u n i ­ versal mechanisms determine w h a t i s to b e learn ed an d how i t will b e expressed . H e also relates learn ing and behavior to the biological p rinciple o f adapta ti on to the environmen t . C hom sky h as played a key role in the evolution of learn ing theories as the crit ic who focuses atten tion on the presu m ed weaknesses i n the Skinnerian attempt to extend traditional S -R conn ection ist p rinciples to the acq u isition o f language. While h is academ ic background is in psycholinguistics rather than learn in g theory, h is pun gen t (if d i fficult to u n d erstand ) wri ti n g h as served as a rallying point for cogn itive theorists in their o pposition to the Skinneri an s . The third theory i s that of the Swiss Jean Piaget, who i s also n o t a psycholo ­ gist b y train i n g . With a Ph . D . in biology, h e retained h i s biologist's interest in ad aptive processes when he began to watch h is own ch ildren . From these obser­ vations, he developed a theory that relegitim ized structuralist an d maturational variables in psychology . Because o f h is emph asis on developmental an d m a t­ urational variables, h is theory was first i n troduced to American psychology s tu d en ts as a developmen tal theory . It is, however, a true theory of learn i n g wh ich s uggests t h a t d ifferen t laws of learn ing m ay apply at different m a tura­ t ional stages . In its emphas is on maturation , Piaget's theory represents an extension and refin emen t o f Maria M ontessori's focus on matu rational variables . I n i ts concern w i th the anatomy of th inking, or cognitive s tructures, P i aget's theory is also s tructuralis m , in the mode of Ti tchener, Lewin , C hom sky, a n d , to a lesser ex­ tent, Salt z . Recently, the i mportance of h is theory to the field of learning has b ecome increasingly recogn ize d . When the author began work on this text in 1974, no maj or textbook on learn ing conta ined a chapter on Piaget. S ince that time, several texts ( H ilgard and Bower, 1975 ; H ill, 1977) h ave done so . The fou rth theory, by Donald Norman , represen ts the i n form ation ­ p rocessin g v i ew o f l earn in g . Perhaps b ecause o f the i den tification o f this v i ew with the concepts an d j argon of the rapi dly advancing field of com p u ter technol­ ogy, it h as become increasingly i n fluen ti al in recent years . While Norman sees learn ing as involving active internal processes (as do the other cognitive theories reviewed in this book), he explains these processes in mech an istic term s . For exam ple, plans and s trategies for learn i n g are viewed as sim ilar to the programs wh ich control the o perations of computers . The inform ation - p rocessi n g ap­ proach is also d istinguished by i ts emphasis on learn ing as a multistage process . S elective attention is the first s tage followed by several memory s tages and a con tin u in g process o f incorporatin g learn ed material i n to existing concepts ; retrieval mechan isms are the last stag e . In reading the m aterial in th is chapter, you should note the ways i n wh ich these theories d iffer an d resemble one another . You should become fam iliar with major term s in the j argons o f each theory and see how a term u sed to describe a given concept � ay h ave the same meaning as a d i fferen t term u sed by another

/vl od ern Con ten ders

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of these theorists to describe the same concept . Try to follow the seq uence in w h ich these theories are presen ted in term s of more and more incorporation of b i ological variables . Finally, relate each of these approaches to earli er rela ted theori es-Saltz to functionalism and Tolman; Chomsky to gestalt; P iaget to M ontessori ; and Norman to the short section on cybern etics in Chap ter 5 . S eeing the relation s h i p s among the theories presented in this chapter and previous materi al will aid you in understand i n g an d l earn ing the fram eworks of these theories . Let u s begin with the theory ( Saltz) most related to the mainstream of academ ic learn ing psychology. C oncept-Leaming Theories and the Concept- G rowth M odel of Eli Saltz

One characterist ic s hared by most connectionis t theories o f learn i n g as well as by behaviorist ic-cogn i tive theories (Tol man , Bandura) is that b asic laws of learn­ ing govern the b eh avior of all h igher an imals . Behavioris ts' formulations of such laws were often based on a n imal research b ecause the env i ronments of an im als could be precisely con trolled . This allowed m an ipulation of selected in depen ­ dent variables with a m in imum of in terference from extraneous variables . I t is true that some connection ist theoris ts m a in tained that h i g her organisms ( incl u d ­ i n g hum ans) m ig h t also s how learn in g reflective of more complex processes than those presu m ed to account for con dition i n g . These theorists, however, assumed that an extensive knowl edge of the l aws of cond i tioni n g was necessary before com plex learn ing could be understood . From this viewpo i n t, animal s tu di es were seen as provid ing sim pie mo dels or analogs of the basic processes of all learn ing which would provide the d ata base from w h ich to derive the laws of com pl ex learni n g . Sal tz (1971) h as l aunched a vi gorous a ttack on th is approach to understanding learn ing of e ither the condit ion ing or con1 pl ex types .

Concep ts as the Basic Unit of Learning F irst, Saltz would agree wi th many of the researchers (Rescorla, Timb erlake and Allison , and o thers) reviewed in C hapters 8 and 9 that the processes responsible for "s imple" con d i tion ing of ei ther the instrum ental/operant or the classical con ­ d ition i n g type are p robably not what was once thought. In fact, they m ay b e more com plex . S econ d , Saltz rej ects a literal in terpreta tion of the Pavlovian and Am erican s trict connec tionis t view of language as a series of in tern al verbal s timuli fol­ lowed by in ternal or external verbal responses . * Defin i n g some words as s tim u l i ( the first word of the p a i r in paired-associate learni n g) a n d other words as responses ( the secon d word of the pair) fa ils to predict the res ul ts of many pa ired- associate stu d ies (such as those reported by H o u s ton , 1 964, and Asch , 1968) wh ich s how that ei ther word of a pa ir can b e g i ven a s a response t o the o ther word . Since backward con d i tioning in the classical con d i tion ing paradigm is thought to be weak or nonex is ten t, the den1 onstrations of backward associa-

*

I t m u s t b e noted t h a t S k in n er also rej ects the l i tera l sti m u lu s-re sp o n se i n terpre t a t i on of verba l b e h a v ior.

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tions (find i n g that a subj ect g iven t he secon d " US or response" word of a p a ir can p ro duce the first "CS or stimulus" word) i n p aired-a ssoci ate learning would su ggest that the laws o f classical con dition i n g do not ap ply to p a ired ­ associate learni n g . H orton and Turnage ( 1976) reviewed the paired-associate learni n g research and concluded that although backward associations are com ­ m only reported , many stu dies have fou n d suc h associations t o b e weaker than forward associations (subj ects fou n d i t easier to recall the second word after presentation o f the first word than t he other way around). It could be s uggested that the evid ence for asymmetry ( the second word is not as effective a stimulus as the first word) i n p aired-assoc i ate l earni n g results from the fact that the relatively s tron g b ackward cond i tioni n g of the first word to the second word is weaker than the forward cond itionin g o f the second (US or response word) to the first (CS or s t im ulus) word . In any case, since the classical con ditioning l iterature provides l ittle b asis for s trong backward con di t ion i n g , the vi ew o f Saltz ( 1971) and Asch ( 1968) that stimulu s -response conceptions of associative learn i n g s hould be abandoned i n favor o f see i n g b o th words a s associated w i t h a central process or concept seem s cre d ible . Follow i n g h is review o f the i nadeq u ac i es of the classical conditioning p ara d i gm in predicting the results of paired-associate learni n g , S altz (1971) s u g gests that the common p ractice of beginning the study of learni n g with conditioning and later attempting to d iscuss concept formation i n terms of con­ d itioni n g should be reversed . H is reasoning g oes as follows : C onceptual behavior d is pl ays in a fairly clear manner the comp lex organ i zation of p sychol o g ical variables which i s often only obliquely in tersected by s i m pler learn ing s ituations . Thus, wh ile t h i s organ ization of variables is crucial to the s i m pler learn ing si tuations, these simpler learnin g s i tu at i ons m ay not be opti­ mal i n s truments for d iscovering t he s tructure of in tellectual processes . [Sal tz , 1 97 1 , p . 30]

Thus, for Saltz, the b asic u n i t of learn i n g is a concept rather than an S -R bon d . Becau se o f t h is e m p h asis, he spent considerable time develo p i n g h is definition o f a concept. Concepts are defin ed as "boun d ed sets of attri b u tes . " Attrib utes are d iscrim inable stimulus characterist ics o f the external and i nternal environ­ m ents experienced by the orga n is m . Q ualities such as "red" and " round" are examples of attrib utes. B oundedness is an organiza tional variable (like the ge­ stalt laws) and is determ i n e d by the p ersonal and cultural h istory of t he h u m a n s u bj ect. This variab l e , which determ i n es how we ten d t o grou p attributes within s p ec i fic concepts, is related to Lewin' s concept of b o u n d aries as isolating regions of our l i fe s p aces . The results o f b o u n d ing attributes d i ffer from i n d ivi du al to i n d ividual . A particul ar set of attributes may be organ ized by a person ( or cultu re) as a c oncept so that certain instances w h ich appear t o p ossess these a t tr i b u tes can be reacte d to in a s i m i lar manner. If someone c u ts t he a ttr i b u te pie d ifferently, he m ay emerge w i t h a d ifferen t set of concepts . In th is sense, one concep t is as " true" as ano t her. [Saltz, 1 971 , p . 31 ]

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Exam ples o f the relative nature of concepts i nclude the ways d i fferent languages label groups of t h i ng s . In M a n darin C hi n ese , there is one word for wet fru its and wet n uts (as cocon uts) and a d i fferen t word for dry fru i ts and n uts . Within each group, no d i fferen tiation is m ade between what we call n u ts a n d fru i t (Saltz, 1971) . Because concepts represent the rul es by w h ic h we d ivi de up real i ty, they h ave impl ications for pred icting behavior, much l ike the reg ions of Lew i n 's theory (at least once the observer knows what the concepts or regions are) . Concepts reflect the i n ternal u n i ts or val ues o f the sets of dimensions, or con­ t i n u u rn s , to which the person pays attention . Examples o f d imensions would i nclude col or, size, and i n terpretations o f behavi or (such as fri endly or hos tile) . The d imensions we focus on in try i n g to decide w h ich of our existing concepts best fits a g iven situation , i n turn , d eterm i n e how we are likely to act or the rules and strategi e s we will employ i n dec iding what responses to make in that situation . The attributes, or specific s ti m ul i m ak in g up a d i m en sion, m ay be e ither simple cues (such as a red light) or com plex concepts i n the i r own righ t . A n exam ple o f an attribute that i s a com pl ex concept would b e " father, " a s the type of person havi n g the attrib u tes of b e i n g male a n d a parent. Whatever the level o f complex i ty of the attributes, concepts are v i ewed by S altz as re flectin g bounded reg i ons i n the person's cogn i tive space w h ich the person reacts to as dis t inct en tities . This n eo - Lewin ian defin i t i on o f concept led Saltz i n turn to d e fine concept learn i n g as the associating and b o u n d i n g (see ing all attributes as part o f that concept) o f the set of attrib utes . Thus, concept learn ing is the as­ sembl i n g o f attri butes i n to a cogn i tive u n it, or gett i n g " the idea" that attributes belong together. These d e fin i t i ons classify Saltz's theory as a p u re cogn i t ive learn ing theory . N o t only is the u n it of learn i n g m olar and cogn itive (as i t was for Toln1 a n ) , b u t the n1ethod o f assim ilating n e w i n forn1 ation i s nonmecha n ical and nonconnec­ tion is t . This is si n1 ilar to Piaget's approach , as we shall see , and opposed to the con n ect ion ists' (incl u d i n g Bandura a n d the social learn i n g theorists) explana­ tions o f concept learn ing . Accordi n g to the Skinneri an connectionists, concept formation is the end res ult of re i n forcen1ent of con1 n1on or s i n1 ilar responses to d issin1 ilar s t i n1 uli . Saltz , like most concept-learn ing theorists o f the cogn i ti ve cam p , totally rej ects the behavioristic view that i n ternal events involved i n learn­ i n g concepts follow the san1 e rules as observa ble res ponses . S i nce the behav­ iorists ' com m on response , or d iscrin1 i n a tion, model of concept forma tion so well illustra tes the cri tical d ifferences in the ways cogn i tive a n d conn ectionist theorists atten1 p t to explain the san1 e type o f con1 plex learn i ng, we will now examine the con1 n1on response theory and cri tical evi dence related to i t . '

T h e t wo word s o f a p a i r i n p a i red -assoc i ate l e arn i n g h ave bot h sti m u l u s a n d res p o n se p ro p ert i es a n d a re asso c i a b l e i n b o t h forward a n d b a c k w a rd d i rec­ t i o n s . Th is p h e n o m e n o n h as l ed S a l tz t o p r o pose e x p l a i n i n g c o n d i t i o n i n g p h eno m e n a i n t e r m s o f c o n c e p t- l ea r n i n g p r i n c i p l e s . Con ce pts a re b o u n d ed ( asso c i ated ) sets of a tt r i b u t es ( c u es o r si m p l e r c o n c e pts) wh i c h a re seen as h av i n g so m e q u a l i t i es i n co m m o n .

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The Co 111 1n on Response Model of Concep t Learn ing and Saltz's Critiq u e In the b e haviorist (incl u d i n g social learn ing) view, concept learning is seen as a complex form o f d iscrim ination learn ing that can b e explained in term s o f con ­ n ec tionis t principles . This continuity (as o p posed to i n sight, or s trategy-based noncon tin u i ty) m o d el ass u mes that a s u bj ect learn s a concept by emitting the cri tical res ponse to successive s timuli, some times correctly and some ti m es i n ­ correctly . Even tually, he learns t o restrict t h e response t o only the correct (re i n ­ forced) s e t of stimuli . As in o ther form s o f d iscrimin ation learning, t he role of d isconfirming instances (errors, nonreinforced responses) is seen as vital by most connection is ts (you may wish to review the d iscu ssi on on this topic pre­ sented in Chapter 9) . Most connection is t the oris ts ass u m e that errors either function to extinguis h the tendency to generalize responses to incorrect s ti m uli or res ult in the incorrect stim uli's becom ing CSs ( i n hibitory stimuli) or S �s (cues signali n g the probable nonoccurrence of reinforcemen t) . S i nce the d iscrim ina tion/common res ponse m o d el of concept formation treats concept forma tion as a complex tri al - a n d - error situation , laboratory tes ts are usually designed to make errors l ikely . S al tz ( 1971) has l isted three critical issues related t o the b ehaviorist ic ap­ p roach to concept formation which require experim ental resolut ion : (1) how t he type of "instructional set" produced by the experim ental situation and the intel­ ligence an d/or m a turity of the subj ects rela tes to concep t learn ing, ( 2) the degree to which reinforcement automatically leads to selec tion of the reinforced s ti m uli as opposed to the im portance of awareness o f the contingencies, and (3) the role of errors, or i n formation about whic h stimuli do not fit within a concept (nega­ tive information) . Let us now review research related to each of these issues in turn .

S tra tegies used by subjects as a fun c tion of exp erilnen tal situa tions and other Sal tz and Hamilton (1969) found that in an experimen tal situ ation va riables whic h forced the s u bj ects to u se trial-and- error concept-learn ing proced u res, c hildren with IQ s of around 80 m a d e no more errors on the average than chil­ dren with IQs averaging 130 . This suggested that tasks of the trial-and-error type force all s u bj ects to behave in a m echan is tic way. Performance of this type was fo und to have li ttle relationship to o ther i nd icators o f intell igent behavior (such as the subj ects' IQ scores) . Hence , evi dence o f concept learn ing by trial and error in a restricted laboratory setti n g may reflect the restrictions more than the normal hypo thesis - testing behaviors of unrestricted s u bj ects . Saltz's and Hamilton's s u bj ects l earn ing the trial-and-error concept- form a tion tas k s howed mastery o f the p roblem on one particular trial . This a ppears to contrad ict the com m on behavioris t assum ption that learn in g is the result of the grad ual s trengthening o f a bon d (the con tinuity position) . Because d i fferen t c h ildren ach ieved this mastery at d ifferent times, however, the gro u p curves s howed what appeared to be a grad ual incremen t in correct solu tions over trials, wh ich could have b een m isinterpreted as supportin g t he continu ity posi tion . The strategies, or types of learn ing, of human subj ects have also been

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s hown to be a function o f maturational level. Ken dler an d Kendler (1975) have reviewed the res ults of their experimen ts u sin g the reversal/nonreversal s hift procedure. A reversal s hift is a switch to an opposi te choice following nonre in­ forcem en t of a choice that had formerly been rewarde d . This ten d ency, which develops after experiences with multiple reversals, is representative o f a learn­ i n g set of the type presented in C hapter 7 in the discussion of Harlow's researc h . As such, it shows noncontinuous or apparen tly " in s i gh tful" learn i n g as o p ­ posed t o associational or continu ous learn i n g . In the Kendler p aradigm, reversal s h i fts required changing fo ur associations of compoun d stimuli; nonreversal s hifts req uired c h an ging only two S -R association s . Therefore, S -R continuity theory would predict, nonreversal s hifts should b e easier . C o gn itive t heories, in contrast, would assume that the s u bj ects had learn ed a rul e which mediated between stimulus and res p onse and that this rule would allow qu ick changes of responses over cue dimensions (reversal s h i fts ) . The K en d lers fou n d that college studen ts and children over the age of five fo u n d reversal s hifts easier, an d younger children and laboratory an imals found nonreversal s hifts easier . These results fi t with L uria's observations (Chap ter 8) that younger chil dren's learn i n g i s more controlled b y first signal system (environm en tal) cues and older chil­ dren ' s l earn i n g is based m ore on internal second sign al sys tem (semantic or mean i n g) variables . Based on ideas such as t hese, S altz has concluded that concept l earn ing may occur in ways predicted by the com mon response, or behavioris t, model when the environm en t is res tricte d to prom o te trial-and­ error learn in g or when the s ubj ect's matura tional level or in telli gence l evel pre­ cludes a more in tern al, cogn i tive typ e of concept learn ing . In older in telli gen t h umans function ing natu rally, however, concept formation is b es t d escribed in noncontinuous hypothesis -tes ting term s .

The role of a zvaren ess in learn ing

Saltz' s second cri tical issue-the roles of reinforcement an d/or awareness-caused him to review Tolman's latent learn i n g s tu d ies . S altz concluded that neither reinforcen1 en t nor awareness i s necessary for learn i n g . Studies o f concept a tta inmen t o f the verbal learn i n g type (s uch as guessing which class of words will be followed by reinforcem en t) h ave, for the most part, shown that awareness of reinforcement con tingencies is n ecessary for an increase in o perant rate o f the selected words . These s tu d i es, however, d id not d isprove the theory that the gradual acq u isition of learning ( versus perfor­ mance) could occur as a fu nction of reinforcen1 ent, even withou t awareness of the contingencies . Silver (1967) fo und that by usin g procedures d esign ed to mini mize hypo thesis tes tin g in college s tu d en ts, the reinforced learn ing of a preference for a particular tense in conversation could be i ncreased withou t the s ubj ects' reporting awaren ess of the ir changed res ponse patterns . After further s tudies, Silver, Saltz, and Mod igliani (1970) concluded that learn ing with awaren ess, or by awareness, is maximized by experim ental procedures promot­ i n g hypothesis testing, and that learn i n g as an unconscious result o f t he effects o f reinforcen1 ent is max imized by experimental p rocedures of the trial-and-error type. G iven Saltz's and H amil ton's (1969) results showi n g that reinforcement­ dependent learning o f concepts does not correlate with IQ, it may be that non-

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aware learning reflects a more p ri m itive process not rep rese n ta tive of i n tellige n t h um a n behavior. I n addi tion, Saltz and colleagues ( 1 970) sugges t t h a t i n telli ­ gent, hypothesis - testing approaches t o concept attainment m a y actively inter­ fere w i th the effects o f " s ubconscious" reinforcement. Evidence presented in C h a p ter 8 , however, s howed that awareness is an essential precond i tion for mos t types o f h u man classical con d itioning ( B i ferno and Dawson , 1977, 1978) . Levine ( 1 971) has demonstrate d that when s u bj e c ts sampled fro m a set o f i ncorrect hypotheses (controlled by the experimenter) , no automatic res ponse s trengthening was fou n d , i n s p i te o f ideal con d itions for re inforcemen t to s trengthen bon ds automatically . We m ig h t conclude that t he balance o f current evi d ence would seem to support the view that awareness is involved in most kinds of h uman learn in g , although unaware learning may occur i n a few c ircum s tances. U naware learn in g is the type pred icted by the common response model .

The role of errors in lea rning

Positions on the role o f errors i n learn ing do no t d ivide on s tric t cognitive vers u s connec tion is t line s . Bower and Trabasso (1963) , all-or-none (noncontinu i ty) theorists, have presented data supporti n g the ir position t h a t learn ing occu rs only a fter errors . As w e saw i n C hapter 9 , however, Terrace (who i s a connection is t) h as developed a d iscrim ination­ tra i n i n g m e thod ( fading) i n 'vh ich the s u bj ec t may never make responses to the incorrect cues and hence may never experience nonre inforced trials-an d yet learn ing occurs . Fre ibergs and Tulvi g ( 1961) fo u n d that human subj ects firs t enterin g the laboratory h a d d i fficulty i n processin g n e gative i n form ation , o r informa tion res u lting from incorrect choices . With t i m e , as well as practice with 20 d ifferent p roblems, the subj ects s teadily gained i n their ability to u se i n for­ mation from their errors . Saltz ( 1971) s u g gests that s tu dies s how i n g negative i n p u ts to be cru c ial reflect methodological artifacts . Further, he concludes, the fact that the s ubj ects in Freibergs's and Tulvig's s tudy were i n itially so poor i n u sing ne gative i n formation suggests that they h a d not h a d much practice using t h is information in the o u tside world . Tha t their d i ffic u lt ies were not caused by the d i fficu l ty o f u si n g n e gative informa tion was s hown by their rap id learning o f how to u se t h is i n formation . Therefore, the resu lts o f various laboratory s tu dies (such as those p erformed by Bower and Trabasso) s howin g learn i n g from errors to be an essential p art of concept (and o ther) learning reflected the peculiar effects of those laboratory procedures . Saltz in terprets th is to s u g ge s t that n a tural concept learning is not a trial -and-error d iscrim in ative task in wh ich nonreinforcem en t o f incorrect responses weakens tendencies to res pond to ir­ relevan t a ttri b u tes . Therefore , while Saltz admi ts that s u bj ects may use negative information in the laboratory or s how trial-and-error learn i n g in such res tric ted environm en ts, t h is does not mean that such d e monstrations pre d ic t how s u b ­ j ec ts will learn concepts in the ou tside world . Even i n the laboratory, s u bj ects d o not learn only on error trials . Levine (1966) , wh ile fin d in g t h a t m o s t s ubj ects focus on incorrect responses, reported d a ta th a t see m s to show that learning occurred on both error and correct trials i n a hypothesis -testing task . S u p pes and Schlag-Rey ( 1965) , measuring ch anges i n verbal classifica tion hypotheses

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after correct and error tri als, found changes in classifica tions to occur almost as often after correct responses as after errors . H ence , these results seem to sup port Saltz to the exten t of showing that errors are not essential to concept learn ing, but they fail to support h is contention that s u bj ects always have initial difficul­ ties with processing negative i n formation . T h e c o m m o n res p o n se ( b e h av i o r i st or c o n t i nui ty) m o d e l of co n c ept for m a t i o n states t h at co n c e pt l e a r n i n g i s a m atter of co m p l e x , un aware, t r i a l -a n d -er ror l e a r n i n g i n w h i c h n o n rei n f o r ced errors a re i m p o rt a n t . T h i s m o d e l see m s to p red i c t best w i t h youn g c h i l d ren a n d a n i m a l s . Laboratory c o n d i t i o n s m ay a r t i fi c i a l l y i n c rease use of i n fo r m a t i o n fro m er rors, un aware l e a r n i n g , a n d use of t r i a l -a n d -er ror s t rate g i es , w h i c h are l i n ked to t he c o n t i nui ty m o d e l .

Types of Concep ts a n d S tra tegies for Assigning Attrib u tes to Co11cep ts Saltz, l ike many o ther modern cogn i tive learn ing theoris ts, h as described the characteristics of concep ts in profu se deta il . F u rther, he d ivides concepts into four basic types . Al though the way each typ e is form ed varies, all share the p roperty that each defining attrib ute elici ts the entire response associ ated with that concept . 1 . A simple concept i s a conce pt opera t i on ally d e fin ed b y bnly one a ttr i b u te , s u c h a s the conce pt " red . " Apples, barns, a n d comm un is ts would a l l elic i t the concept res ponse . These concepts are tigh tly " b ou n d " ; once a s u bj ec t iden­ t i fies the concept, accuracy is very h i g h .

2. A conj unctive concept i s a relational conce p t ; that is, two or more d e fin i n g a ttri bu tes m u st be presen t s i m u l taneou sly . A n exa m ple presen ted earlier w a s " father" as a com b i na tion o f the a ttri b u tes " m ale" a n d " paren t . " I n the laboratory, an exam pie would be tri a ngular + red . S i ngle a ttr i bu tes, such a s a black tri angle or a red c i rcle, wou ld no t elic i t t he concept res ponse . •

3 . A d isj unctive concept h a s two su btypes, incl u s i ve ( a n y one of a se t of a ttr i ­

butes i d en t i fies the conce pt) o r excl u sive ( a n y one o f a se t o f attr i b u tes i d en­ t i fies the concept, exce pt when they occ u r toge ther) . An ex arn ple of the first type ( i ncl u s i ve) would be ei ther d el u s i ons or hall u c i n a t i o ns a s defi n i ng ' s c h izophren ic . " A n example of the second type (exclu sive) would be the concept of p u rebred an i ma l . A p u reb red dog can be a beagle or a boxer, but a " be ager" i s not a p u rebre d d o g . Th i s type of conce pt i s m o s t com m an in labora tory experi ments . -! . A probabil istic concept i s

conce pt in wh ich s pec i fied attri b u tes s u ggest the concept but do not clearly i d en tify ( d efine) i t . Tex tbook- rea d i n g behavior is an attri b u te t h a t is h ighly correlated w i t h the conce p t "s tuden t . " If you saw someone rea d i n g a tex tbook, yo u would be l i kely to clas s i fy h i m a s so meone fi tt i n g yo u r conce pt of s t u d en t, w h ile he n1 i g h t in fac t j us t be someone w i th a h igh tolerance for bore d o m w ho liked to read such tex ts for a m u semen t . I t is assu m e d th a t so me a tt r i b u te must ex is t somewhere to d e fin e the conce pt ( i n o u r exa m p l e , i t m ig h t b e proof o f s tu d ent reg is trat ion) , b u t t h i s d e fin i t i ve attri b u te i s u su ally not ava il able . a

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The system for classifying concepts (rules d eterm in ing how s u bj ects w ill respon d or d iscrimin ate) proposed by S al tz is very sim ilar to that advanced by Bruner, G o o dnow, an d Austin ( 1 956) and other concept-learn ing theorists . Bruner and colleagues h a ve also identified several strategies u sed by subj ects in determin i n g w h ich type of concept to use. These incl u d e the whol ist strategy, in w h ich the s u bj ec t rem embers all the attributes common to correc t instances and ignores o t her information (s uch as negative information) and the partist strat­ egy, in whic h the learn ing focuses on one hypothesis at a t i m e . They have also identified subtypes of t hese s trategies whic h were applied when the ir subj ects were exposed to a b o ard with 81 stimulus cards and requ ired to p ick cards one at a time and tell if they t hought each card was an example of t he concept. Some s u bj ects p icked one positive card an d selected subsequ ent cards which changed one attribute value at a time ("conserva tive focusi n g" ) ; o ther s u bj ects began with their positive card and then p icked subsequent cards which changed sev­ eral attribute values at once ( " focus gamb l in g") . Both these s trategies were sim ilar to the who l is t strategy . Other s u bj ects b egan with all possible hypothe­ ses and eliminated i ncorrect ones after each following card ("simultaneo u s scann in g") . Finally, som e subj ects began w ith o n e hypothesis and changed it when i t failed to pred ict positive instances ("successive scanning" ) . These last two s trategies were related to the partist s trategy an d were fou n d to be less e fficien t than the focusing techn iques . The main point for u s to derive from this research is that d ifferent s u bj ects u sed d i fferent learni n g strateg ies in varied learn ing situ ation s . S a l tz ( a n d o t hers) h ave c l assi f i ed c o n c e pts i n to d i ffere n t types. S i m p l e c o n ­ ce pts a re d efi n ed by a s i n g l e a t t r i but e , c o nju n c t i v e c o n c e pts a re d ef i n ed b y t w o o r m o re n e cessa ry att ri butes, d isjun c t ive c o n c e pts a re d ef i n ed by mul t i ­ p l e a t t r i butes w h i c h e i ther a re n o t requi red t o a p p ear t o g et h e r o r m us t n o t a p p e a r t o g et h e r , a n d p r o ba b i l i s t i c c o n c e p ts a re sugg ested by a t t r i butes t h at d o n o t a l ways s p e c ify t he m . Subj e cts m ay us e d i ffere n t st rate g i es t o assi g n a t t r i butes t o c o n ce pts.

While Bruner an d colleagues ( 1956) h ave i d en t ified several s trategies that s ubj ects may use to assign a ttributes to concepts, Saltz m a in t a ins that children begin with a single s trategy, wh ich he i dentifies as concept growth . Let us now examine t h is concept-growth m o d el of t he acq u isition of concepts.

The Concep t-Grozv th Model Trad itional d iscri m in ation models of concept formation assu m e that the s u bj ect begins with a category and gradually l earns which instances to eliminate (note the emphasis on negative inform a tion) . Saltz s ugges ts that a ch ild starts wi t h a single positive instance ( that is a d o g) an d gradu ally adds new attribu tes ( poo­ dles are dogs, also) . Gradu ally, through d irect experience an d through h i n ts from models and con texts, t he concept " grows, " or is expande d . Sal tz once asked an e ig ht-year-old boy how the ch ild had m astered a p articular concept and was told that " someone told me" (S altz, 1 971 , p. 56), showin g concept growth

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resulting from in forma tion given by a dults . This growth" mo del would pred ict th a t c h ildren would tend to m ake more errors of o m ission than of comm ission (not calling S aint Bernards dogs instead of calling cows dogs) . S al tz and Sigel (1967) fou n d that young children d i d ten d to overd iscrim in ate, or use an overly restrictive criterion . Even eight-year-old children consistently refused to classify fathers who were i denti fied as drunkards as fathers . * This absence of over­ generalization is directly contradictory to t he results pre dicted from the d iscrimination/common response theory of concept forma tion . M ore recently, S al tz (1973) has fou n d additional evi d ence that you n g ch il dren form n arrow concep ts . When asked to classify items as clothing or not-clothing, children d i d not inclu d e hats, shoes, a n d gloves i n the conc ept o f clothi n g . N elson (1974) h as noted that children may either overgeneralize or u n d ergen eralize concepts . S he conclu des that children's concepts are based on core" functi on al relation s ; w hen n e w examples d o confoun d these simple functions, u n d ergen eralization m ay result . Thus, t he fact that the man in Sal tz' s second exam pie h a d d octor functions may have b een responsible for the children 's refu sing to dassify h i m as a father . S al tz ( 1971) h as reviewed stu dies by J u n g which he interprets as s u pporting h is concept-growth model . In these stu dies, subj ects first learne d a few p airs of words very well (which S altz would see as learn ing a concept with good bound­ ary strength which would b e resistant to interference ,effects) . These s ubj ects learned n ew p a irs of words presen ted s uccessively m uch more easily th an sub­ j ects presented initi ally with the entire l is t . Saltz s uggests that the first sm all s ubset of p a irs of words h a d b ecome a conj unctive concept w h ich was able to grow t hrough t he incorporation of new p a irs of words . The whol ist s trategy i dentified by Bru n er and colleagues (1956) could also be in terpreted as a concept-growth strategy . As in Saltz's model, the first positive instance is taken as the initi al hypothesis, or concept. When n ew ins tances are encoun tered , the s ubject modifies the strategy to incl u d e only attributes com­ mon to the new ins tance an d the e arly concep t . This strategy red uces the sub­ j ect's memory load and provides the mechan ism by wh ich whole ges talts, or things wh ich can be incorporated into whole ges talts, are n1 ost easily remembered . /1

/1

T h e c o n c e p t- g rowth m od e l states t h at c h i l d ren beg i n by l e a rn i n g s i m p l e c o n ­ c e pts b as ed o n a si n g l e d ef i n i n g attri bute. These c o n c e pts t he n beco m e m o r e g en er a l by g rowi n g t h roug h ad d i n g ad d i t i o n a l att r i butes ( w h i c h a l so m a kes t h e m i n to m o re c o m p l e x types o f c o n c e p ts ) . The m ec h a n i s m rese m b l e s B ru n e r ' s w h o l ist st rategy.

*

W h ile e i g h t y e a r o l d s m ad e t h e i r class i fica tions on m oral istic gro u n d s ( b e i n g a dru n kard removed a m a n from the category of fat her) , fi ve year olds u sed even m ore restrictive cri ter i a . A m a n iden t i fied as a doctor w a s n o longer classified as a fa ther (Sal tz a n d S igel, 1 967) .

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S altz' s Version of the In terference Theory of Forge tting Not o nly does S al tz see concept forma tion a s i nvolving a gradual growth pro­ cess, he also maintains that most i n i tial positive instances of a concept are learned i n a single trial (as found by Saltz and Hamilton, 1969) . While t h is notion sounds as con trary to o ur experience as i t d i d when introduced by G ut h ­ rie , S altz d o e s not use G uthrie's e xplanation that apparently gradual learn i n g i s the res ul t of increments in the numbers of tiny S-R bon ds, each b e i n g forme d in one trial . S altz suggests that m o s t ( i f no t all) of o ur "learn i n g" does occur on one p articular tri al, b u t most of this learning never gets beyond a temporary s hort- term memory s tage . Competing cogn i tive elements (Silver, 1967) cause " forgetting" to occur almost as fast as the original learni n g . Therefore , the study of learni n g must be concerned with two types of variables : 1 . Associative variables, as i n G u thri e's theory, which reach their maximal s trength i n a single trial

2. Resistance - to - i nterference variables, which i ncrease t heir effects slowly w i th time and tri als

Let us now look at a simple tes t of this theory, which you can perform yourself. When you are given the instruction, q u ickly turn to the next p a ge a n d glance for an instant at the capitalized word at the top of the page . Do not read anything else on that page . Then turn b ack to this page and count by twos to 40 slowly to yourself. Try not to h ave any o ther thoughts except the numbers and do not repeat the word on the next p ag e . Are you ready? Turn now ! Welcome b ack to this page . H ave you fin ished counting? Do you remember the word ? I f so ( a n d most of you will remember the word) , y o u h ave demonstrated " learn­ ing" which occurred i n one exposure to the word and s tayed i n memory i n s p i te o f yo u r preventing yourself, with the help of the counting task, from rehearsi n g . Because the c u e s i nvolved in s uch a counting task are irrelevant ( a n d d issimilar) to the cues o f reading words, S al tz assumes t h at this type of task also protects the memory trace from i nterference . This i n terference model o f forgetting ( also presented in C h a p ter 7 in the m aterial on transfer effects) can accou n t for the serial position effect, in which t he words at the start of a l is t are learned first, followed by the words a t the end , and finally by the words i n the m iddle o f the l is t . S al tz s uggests that all the words i n the list are learned with equal ease , b u t that words i n the m i d dle receive in terference from words at both the s tart and end o f the list. In S al tz's theory, practice does not create bonds, it re duces forget ti n g ! Hence, learni n g is a s hort-term memory p henomenon, b u t " well­ b o u n d ed" and i nterference- free memory is a long-term memory p henomenon . I n reviewing the literature o f s tu d i es u sing the p aired-associate list p arad igm, Saltz (1971) concluded that speed of "learn ing" (or d evelop i n g freedom from interference, i n h is model) was most predictable from information abo u t the sim ilarity of the words m aking u p the p airs of the l is t . The more sim ilar the words, t he slower the learning, whic h is congruent w i th most cognitive or functionalist models of transfer o f tra i n in g . Where similar s timuli control one

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SERENDIPITY response, these stimuli prod uce proactive inhibition of learn ing fu ture w ords and retroactive inhibition of recall of previously learn ed words . Such negative tra nsfer effects were min imal w hen d ifferen t stimulus words could be u sed for a common response. Saltz sugges ts that the apparen t "learn ing" cu rves fou n d in investigations of classical cond itioning represent interference effects ra ther than gradual incre­ ments in bond s trength . H e cites stu d i es by Vo eks ( 1954, 1 955, i n Saltz , 1971) in w h ich the interference of extraneous poten tial CSs was m in im ized . Under these cond itions, half of Vo eks's subj ects s howed one- trial learning of the condition ed ey eblink response, dem onstrating that even classical con ditioning cannot al­ w ays be explained as a process of gradual increm ents of assoc iations . Voeks's results are interpreted by Saltz as supportin g h is own idea that a stu dy of concepts may eventually prove more useful in explaining "cond ition ing" than the other way aroun d . One reason learn ing often appears gradual, Saltz expla i ns, is that con­ cepts gradually grow in the d irection of becom ing more d ifferen tiated fro n1 each other . This grad ual increase in concept d i fferentiation , w h ich is in marked con ­ trast to the all-or-none development of associations, results in increased resis­ tance to interference-hence, to im provin g levels of perform ance. '

S a l tz s u g g ests t h at w h i l e st i m u l i a n d res p o n ses beco m e asso c i a ted w i t h e a c h o t her a n d w i t h e x i s t i n g c o n c e pts i n a s i n g l e t r i a l , res i s t a n c e to i n terferen c e d e ve l o p s s l ow l y, t h ro u g h a p r o cess of c o n c e p t d i ffere n t i a t i o n , o r " g ro w i n g a pa rt . . . A p pa re n t l y , g r ad u a l l e a r n i n g is g r ad u a l d ev e l o p m e n t of res i s t a n c e t o forg ett i n g , o r c h a n g es f ro m s hort-term m e m o ry t o e n d u ri n g c o n c e pts.

I11 tcg ra tio11 of tlzc E le111 c11 ts of a Co ncep t In add ition to the process by wh ic h cues, concepts, and con1 peting el en1en ts become d i fferentiated , or acq u i re bound ary strength in the cogni tive space, another i n1 p ortan t process occurs in concept " growth . " Th is is integration, or the transforma ti on of un related el en1 en ts into a cogn itive en ti ty . It req u ires that at least son1 e d i fferenti ation has already occurred an d , in tu rn , fac il i ta tes further d i fferentiation . In learn ing read ing, ind ivi dual letters o f the alpha bet n1ust first be d i fferen tiated from o ther visual s tin1 uli before the ch ild reacts to then1 in a n1 eani ngful way. Once the ch ild knows what l etters are, he or she can learn to assemble then1 into w ords or to in tegra te them into larger u n its . In th is process, the ch ild first learns the concept of the alp habet, then w ord concepts wh ich are d i fferentiated fro n1 each other, and fin ally sen tence concep ts . Once words are learned and di fferentia ted fro n1 each o ther, each word can h ave di fferen t attrib u te functions in d i fferent sentence concepts j ust as a given letter has d i fferent attri bute fu nctions in differen t word concepts . As a concept wh ich is used as an attribute, a word has defin ing ch aracteristics (its meaning) n1 uch l ike an y simple, conj uncti ve, or d isj u nctive concep t . ( A s an example o f a

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word serving as a d isj u nctive concept, the word "read" can have a present tense meaning in one sen tence concept and a pas t tense meaning in another sentence concept, b u t not both mean i n gs in the same sen tence concep t . ) Wh ich d e fin ing attribu tes are used in a particular sen tence concept d ep ends u p on the meaning­ fulness o f each possibility in a particular l i n gu is tic con text . This meaningfuln ess is, of course , a function of previously differentiated concepts, in terpretations of what the receiver knows, and o ther integrated lin gu is t ic elemen ts . Saltz s pecu ­ lates that " d ifferentiation o f associational gro u p i n gs may involve the same pri n ­ ciples regardless of their level of complexity o r m olarity" (197 1 , p . 270) . These factors determ ine how easily a new word, or a meaning of a word, will b e learned . New material wh ich can be integra ted with existing concepts is, o f course, most easily learn e d . This facili tation effect is called mediational facili­ tation . Saltz ( 1971) h as shown that s u bj ects presented with " nonsense words" o ften code them ( m e d iate them) as soun d in g l ike or b e i n g u sed like well-known real words . Th is illustrates the principle that the mechan is m s of i ntentional learn ing or seeking of mea n i n g (actively mediated l earn in g) are much m ore crucial for poorly d ifferentiated material such as nonsense words . S eek ing meanin g is another term for seekin g to relate new inform ation to existing concepts . S i nce existin g concepts have good boundary s trength , n ew material added to such concepts should have m ore resis tance to forge tting ( in ter­ ference) than unrelated material . Thus, m ea n i n g is a m ed iatin g variable wh ich prom otes fas t learn ing and good retention by facil itating associations . This as­ sociative mod el of mem ory fits well with what is known abou t m e m ory a ids, or mnemonic devices. These devices (to be d iscu ssed near the end of this chapter) represent deliberate attempts to associ a te new inform ation with existing con ­ cepts . Associative techn iques for a id i n g m em ory c onsistently yield better reten ­ tion than d irect reinforcemen t of responses or rote practice procedures . Reed and R i ach ( 1960) found that s u bj ects tol d to " associate" when confronted with a l is t of p a ire d associates learned faster than s u bj ects tol d to "learn the list . " M a k in g deliberate efforts to associate unrelated stimuli causes these stimuli to b ecom e in tegrated i n to concep ts ; th is shows th at "m ean ing" can b e the result of an active, volun tary process ra ther than being an i n trinsic property of stim uli . I n t e g rat i o n i s t he p ro c ess by w h i c h p revi o u s l y d i fferen t i ated s t i m u l i ( ev e n s ee m i n g l y u n re l ated o n es ) c a n b e i nc o r p orated i n t o c o n ce pt s o r fo r m n ew c o n c e pts . De l i berate effort at asso c i at i n g c u es ca n c reate " m e a n i n g , " w h i c h a i d s l e a r n i n g a n d m e m ory.

To sum marize briefly, Saltz has proposed a cogn i tive m odel of learn ing in wh ich the basic un it of learni n g is cogn itive (the concept or life space region) and m olar, and the m echanism of h i gher learn in g is also cognitive . He s ugges ts that many factors and p rocesses, such as con d i tioning and concept formation , are involved (sometimes in com petition) in h is multifactor learn i n g model . H e classi fied concepts in to four basic types-all o f wh ich " grow" with the acqu isi­ t ion o f new a ttri b u tes, the s timulus p o in ts of attentional d i m ensions .

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Persp e ctive Saltz' s is not the best-known of cogn i tive theories, yet i t presen ts a good sam ple of concepts cen tral to verbal learning cogni tive theories . His system of classifica­ tion of concepts is very sim ilar to that of Bruner, and h is i deas about interference are close to the m ore cognitively oriented functionalis ts . M oreover, h is ideas about the fac ilitative effects of assoc iational factors in memorization appear sim i ­ lar to those o f the information-processing the orists a s well a s other cognitive theorists . Other cognitive theorists have gone further i n formulating the rela­ tionship between the types of concepts to be learned and the d i fficulty wi th which they are learned and i n d iscrim inating b e tween attribute learning (learn­ i n g to attend to the correct stim uli) and rule learn ing (knowi n g the rule which u nites relevant attributes) . Bourne ( 1970) has proposed a classifica tion o f ru les which is very close to Saltz's classifica tion of types of concep ts . Bourn e was able to show that trials to sol ution in a concept-learning task was a l inear function of the presu med d i fficulty of using his various types o f rules . Problems i nvolving conj u nctive rules were solved fastest, followed by problems requiring d isj u nc­ t ive concepts, and so on . Bourne ( 1974) assumed that subj ects begin w i th con­ j unctive concepts, and that the extra time req u ire d for them to solve the d isj u nc­ tive concept problems reflected the time req u ired to chan ge their original assumption . N oam Chomsky : A Cogni tive-Naturalist M odel of Language Leaming

Saltz made some concessions to the traditional stimulus-response con nectionis t viewp o i nts . C homsky makes none . Some elem en ts of C homsky's theory an d h is criticisms of Skinner were introduced i n Chapter 4 . The following quotation will give you a fuller appreci ation of Chomsky's criticis ms of the Sk innerian analysis of language learning (wh ich was the leading theory of language performance in the 1950s) as well as introd uc ing you to C homsky's n1etho d of attack (philoso p h ­ ical and abstract rather than experi1nen tal) . Eloqu ence an d logic ( o ften s o con1 plex that i t is d i fficult to follow) are C hom sky's strong points-no t researc h . I n this passage, C homsky attacks Skin ner's idea that a person acqu ires a "reper­ toi re" of sentences (or at least o f words and clau ses and gran1 matical rules) that are likely to be emitted in the fu ture becau se o f havi ng been reinforced in the past. Bu t w h a t does i t mean t o s ay that s o m e sen tence o f Engl i sh that I have never heard or pro d u ce d belongs to my 'reperto ire' b u t not any sentence of Ch i nese (so that the former has a h igher ' probabili ty')? Ski nnerians, at th is p o i n t in the d iscussion, appeal to ' s i n1 i larity' or ' generalization , ' always w i tho u t characteriz­ ing the ways i n w h ich a new sen tence is ' s i n1 il ar' to fa m i l iar examples or 'gener­ alized' fro m the m . The reason for this fa ilure is sin1 pl e . So far as is kno w n , the releva n t properties can be ex pressed only in terms of abs tract theories describ­ ing postu l a ted internal states of the org a n i s m , a n d such theories are excl u d e d , a pri ori , fro m S ki nner's 'science . ' The i m m e d i a te consequence is t ha t the Ski n­ neri an m us t lapse into mystici sm ( unexpla ined ' s i m il ari ties' a n d ' generaliza tion' of a sort tha t cannot be s pec i fied) as soon as the disc ussion touches the world of fac t . [ C ho msky, 1973 , p . 3 1

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The m aj or p o i n t C ho msky m akes in this statement is that we are continually p ro ducing novel sentences (linguistic responses, if you like) whic h , having n ever b een previously em itted, have n ever been reinforced . Principles s uch as generalization from similar sentences emitted in the past (and p erhaps rein­ forced) cannot precisely pred ic t the content or form of n ew sen tences . If we assume, however, that language is organized by i nternal rules ( much like the gestalt theorists thought perception, learning, and memory were organized by i n nate rules) , and that the precise words and grammatical forms u sed in overt verbal behavior reflect the constraints of these rules on how one expresses mean­ ing, then novel com b inations presen t no problem . There are simply m any l awful ways to express a g iven meaning; wh ich way appears on a g iven occasion is only an expression of m o m entary influences acting u p on the in d ividual (such as h is or her assu m p t ions about what h is or her audience already knows) . Like Saltz , C ho msky believes that the appropriate u ni ts o f language learn ­ ing are cognitive sys tems of knowledge and b e liefs . He also sees the cognitive systems as arisin g in early c hildhood through an interpl ay of environmental factors . I n a departure from S al tz and i n general agree m ent with Piaget, he sees i nnate factors as h aving importan t i nteraction effects with environm en tal influ ­ ences . Chomsky postulates the existence of " the sys tem o f linguistic competence that u n d erlies behavior but that is not realized i n any d irect or simple way in behavior" ( 1968 , p . 4) . Competence is rel ated to vvhat a p erson knows, which is d istinguis hed from performance, or what a person s ays or does . In distinguis h ­ ing the p roduct of the learn ing p rocess from response m easures, C homsky i s in agreement with S al tz and with most cogn i tive or cognitively oriented theorists . This system o f l i n gu istic competence is derived from innate organizing factors (whic h m akes it similar to the concept of i nherited intelligence) that form a sort of preexisting syntax (grammatical s tructure) , or natu ral l anguage, w h ich i nter­ acts with cultural and personal environm en tal variables .

Hoiv M eaning Is Tra nsla ted into Sp eech a n d Cons cious Tho ugh t While C homsky's theory allows for individual d ifferences, he also proposes that all h u m an b eings i nherit a similar "lan guage capaci ty" which provides a uni­ versal grammar. By u niversal grammar he means the p rinciples that determine the forms of the particular (that is, ac tual) grammars u sed by h um ans ; the gramm ars, in turn , determ ine the sentence s tructure likely to be u sed in a specific i nstance . These principles are, of course , innate organizing factors . A s a result o f the prop erties conferred by the u niversal grammar on all particular gramm ars (such as the grammar o f standard American Englis h ) , a p erson who knows a specific language h as control of a grammar that can generate an infin ite set o f deep structures. The d ee p s tructure representation of a sen tence ( the kernel sentence) is the way an i dea or meaning is s tored in memory (Tarp y and M ayer, 1 978) and is more abstract than what is actually said or thought. It expresses those grammatical functions that play a role i n interpreting mean ings (C homsky, 1 972) and reflects what a s peaker knows abou t h is or her situation an d what he or s he i n tends to commun icate . G rammar also d e term ines the way

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,\ l oder11 Con t e n ders

in w h ich specific deep s tructures are mapped onto associated surface structure sentences (what we actually say) , w h ich p rovides us w i th a basis for phonetic in terpretation . C ho m sky states that the same kern el sen tence, or deep structu re sen tence, can be expressed in any of a large n u mber of surface structures ( there are very many ways to state most ideas) . I t is this variability w hich con founds the efforts of the S -R theorist to predict wh ich particular sentence w ill be spoken in a given i n s tance. Langu age is not as stereotyped as con di tion ed reflexes . H ones ty forces us to a d m i t t h a t we are as far today as Descartes was three cen turies ago from und ersta n d ing j us t what enables a h u m a n to speak in a way tha t is i nnovative, free from s t i mu l u s control , and also app ro pri a te and coher­ ent . Th is is a ser i o u s problem tha t t he psychologist and b iologist m u s t u l t i ­ n1 ately face a n d t h a t canno t be talked o u t of ex istence by invoking " h a b i t" or con d i t ion ing or " n a t u ral selection . " [ C ho m s ky, 1 968, p . 1 1 ]

C hom sky's answer to the problem posed in the passage j ust ci ted is to suggest that un iversal gra mmar contributes some general (and discoverable) properties to all particular grammars . O ne of these is that only a few si mple rules that express rud imen tary grammatical functions rel ate surf ace structures ( wh ich may b e amb i guous) to deep s tructures ( w h a t is mean t) . S ince we usually do understand what a person in tends to com m u n icate even w hen the phone tic interpretation of what he /she says is ambi guous, Chom � ky states that the mind of the recip ien t of a com m u n ication must perform a series of transformations to relate w h a t was said to an appropriate deep s tructure ( to an u n d erstand ing of what was mean t) . The few transformational rules ( tran sformational gran1 n1ars) can be approximated by try i n g to de term i n e the operations n ecessary to tra n s ­ form a given surface s tructure sentence back t o i t s deep structure forn1 o r to derive a set of surface structure sentences fron1 a kernel sen tence . Cho n1 sky believes that the study of transforma tional grammars hol ds the key to und er­ standing the flexibi l i ty and in nova tive character o f languag e . Le t us now look at some exan1 ples o f C hon1 sky' s approach w h ich illustrate h is further point that su rface s tructure n1 ay be n1 islead i n g . For example, the sen tence , "I d isap prove o f J o hn's cooking, " n1 ay i n1ply e i ther th at the s peaker d isapproves of J ohn's involve n1 ent in cookin g i n general or that the speaker has negative expectations concern in g the product o f J o h n ' s curren t cooking efforts . C ho n1 sky suggests that by transforn1 ing the gran1 n1 ar o f the sen tence by a few simple rules to approxi mate the poss ible deep s tructures, the a n1 b i gui ty may be resol ved . Th us, the sen tence 1n ay be extended to becon1 e e i ther: "I d isa pprove of J o h n ' s cooking because cooking is wo1n en's work . " or " I d isapprove of J oh n ' s cooking w i th s o 111 uch garlic . " It is o f i n teres t that the one hearing the sen tence us ually has li ttle d ifficulty determ i n i ng if the o bj ection to John's cooking was sex is t or culin ary . The tra n s ­ form ations take into accoun t w h a t the s peaker knows a n d w h a t the speaker thinks the hearer knows . The ability of h umans to com m u n icate fairly clearly in s p i te o f the ambiguity of surface s tructu res presen ts a profound d ifficulty for the behavioristic S-R formulations, since w h a t is actually re inforced deri ves its mean ing from the deep s tructure . That is, the responses of langu age are more

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32 1

predictable from deep structure (semantic or m eaning variables) than from t he h istory o f reinforcemen t o f particular words .

Chon1sky' s organizing p rinciples

C hom sky's goal was to determ i n e a fin ite set of rules (organizing p rinciples) w h ich could be used to generate all possible correct sentences but no incorrect sentences . He developed fo ur maj or types of rules ( 1972) to reach this goal : 1 . Phon ological rul es (or m orphop honem ical rules ) , wh ich are concerne d w i th ho w sou n ds can b e com b i ned "legally" to form words . Examples would incl u d e changing the sou n d s of words throu gh adding the e d sou n d at the en d to generate the past tense form .

2 . Base rul es (or phrase structu re rules) , w h ich are t he rules genera t i n g deep structu re syn tax , or the orga n i za t i onal princ i ples of syn tactic u n i ts of l a n ­ guage. B a s e rules speci fy h o w v arious parts o f s peech a re to be asse mbled into sen tences . Examples of these rules are : a . sen tence

=

no u n phrase

b . nou n p hrase

=

article

c . nou n p hrase

=

nou n

+ +

+

verb phra se

noun adj ec tive

+

d . verb ph rase

=

verb

+

n o u n p hrase

e . verb p hrase

=

verb

+

adj ective

article

A sen tence such as " A wise m an is honest" (Chomsky, 1972 , p . 29) can be generated from these rules a s follows : a . sen tence ("A w i se man i s honest") phrase ( " i s hones t") c. no u n p h rase e. verb phrase

= =

no u n ( " m an") verb (" is")

+

+

=

nou n phrase ("A wise man")

adj ective ("w i se")

+

+

verb

article ("a")

adj ective ("honest")

C hom sky suggests that the probable deep s tructure would reflect a system of two propositions, neither of wh ich is asserted d irectly . The two propositions are that the man is wise and the man is honest. What m akes this a system is the i d ea that w isdom and honesty are often found together. 3 . Tran sform ational rul es d escribe how a sentence can be changed i n to an e q u i valen t form wh ich also fi ts the base rules (or rules of syntax) . These are the ru les wh ich also apply to translations be tween s u rface and deep s tru c­ tu res . Chom sky su ggests that the d eep s tructure of the sen tence , " A w i se man is hone s t , " m ig h t be closer to " A m a n who is wise is honest . " The ru les describe permi ssible proced u res, such as changing the order of " m a n " and "w i se" a n d m a k i n g "wise" part of a verb p hrase ra ther than the ori g i n al noun p h rase (in order to make the two original proposi tions m ore explici t) . 4 . P roj ection rules a re ru les for determ i ni n g the mean ing of words wh ich could

have several mean ings d epen d i n g on the con text i n wh i c h they are u sed and on the m ean i n g the speaker wishes to com m u n icate . These would apply to a m b i g u o u s sen tences s u ch a s "They are eating a pples, " in wh ich eating cou ld e i ther be an adject ive describ i ng the type of apple or a ver b .

322

M odern Con ten ders

All o f these types o f rules were a ttempts to explain the flexible and context­ related aspects of h um an langu age. These asp ects of langu age are probably the reason for the failure of early attemp ts at developing compu ter program s capa­ ble of translating one particular h u m an language into another . The words of the sentence, "Yo u look so n ice I could eat you u p , " have a surface structure con­ gruen t with cannibalistic tendencies and would b e so interpreted by a com puter set to respon d by d ictionary defin itions o f particular words . Yet few E nglish speakers would derive o ther th an a m eaning con gruen t with an expression of playful affection, in the ab sence of d isconfirm ing contextu al cues . C ho m sky sees trans formational gramm ars as resolvin g how h u m ans u nderstan d sentences o f the type j ust g iven by provi d i n g cues to the correlations o f sou n ds (the p honem es o f the surface utterance) and m ean i n g (the d eep s tructures) . C ho msky , like Saltz, sees h is seem i n gly complex system ( i n contrast to S - R theories) a s provi ding a simpler m ethod o f learning t h a n the s h ap i n g a n d d irect reinforcement or model ing proposed by the S -R theorists : In h is vi ew, the only substantive proposal to deal with the com plex ities of language acq u isition is what he calls his "rational ist conception . " This essen ti ally consists of ass u m i n g that the h um an m i n d i s innately programm ed to o p erate i n terms of a u n iversal grammar. This grammar consis ts of a subsystem of rules that provi des a skeletal structure for all h um an languages an d sets l i m i ts on the range of variation of the grammars of actual h um an langu ages . He assu m es that the child who learns grammar matches the "meager and degen erate" d ata available to him or her to the res trictions i m posed by the u n i versal grammar. By m eager and degenerate he m eans that a ch ild does not encou n ter all the information n eeded to construct something as s ubtle and complex as the grammar of most human languages from h is or her early interac tions with other h u m ans . The u niversal grammar provides a wide range of possib ilities, only a few of wh ich are not rej ected by the child's observations o f how those around him speak or by others' reactions to his or her attempts at language . Rather than havi n g to invent langu age fro m scratch , the c h i l d h a s only t o fit the d a ta ava ilable t o him (o thers' speak ing patterns and others' reactions to h is attempts) to a fairly res tricted set (specified by the u n iversal gramm ar, by the base rules, and so on) of possible ways of expressing mean i n g and grammatical relations h ip s . By havin g innate categories an d learned cogn i tive structures, the person is able to process seemingly ambiguous ma terial wi th h igh accu racy . As we have s a i d before , the attempts of beh avioris ts to ex tend the i r rigorously d erived prin ­ c i ples t o complex behaviors s u c h as langu age h a s both a d d e d unwanted , u n ­ measurable inner variables and made the theories cumbersome and ad hoc i n character . Chomsky, l i k e Saltz, h a s reduced the number o f principles requ ired to pred ict behavior by begi nning w i th h igher-order (more complex) constructs . C homsky has also j o ined Luria and Pi aget in usin g maturational variables to expla i n d evelo pmen tal chan ges . He suggests that m a tu rational s tages may even­ tu ally be l i nked to the gradual d evelopment o f the full generative grammar o f the adult h u m a n . ( G enerative grammar i s the transformational grammar by wh ich surface s tructures are generated from the d ee p s tructu res . ) Like Piaget, he is a structuralist and believes in i n n a te variables in cogn ition .

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323

For the future, C ho msky sees a rej ection of behavioris m as not inconsistent with m ore recent developments . For h im , as for o ther cogn itive the orists who acknowle dge inn ate factors : Speculating a b o u t the future d evelopment of the subj ect, i t seem s to m e not u nl ikely , for the reasons I h ave men tioned, that learni ng t heory w i ll progress by establi sh i n g the i n na tely d e term ined set of possi b le hypotheses, determi ni n g t h e con d i ti on s of i nteraction tha t lead t h e m in d to pu t fort h hypotheses fro m th i s set, a n d fix in g the cond i t ions u n d er w hich s u c h a hypothesis i s confirmed-an d perhaps, u nd er wh ich m u c h of t h e d a ta i s rej ected a s irrelevan t for one reason or another . [ C ho m sky, 1968 , p . 77]

C ontrol of behavior by environm ental cues is implausible b ecause of the a m ­ b igu ity of those cues and the excessi ve t i m e that the shap ing of b e h avior would take . Thu s, operant p rinciples cannot b e generalized to compl ex h uman behav­ ior, and learning theory m u s t tum again to looking withi n the "black b ox . " C h o m s ky h as d e ve l o p ed a psyc h o l i n g u i st i c t h eory of l a n g u ag e acq u i si t i on a n d u se b ased o n t he i d e a t h at a l l h u m a n s i n he r i t t he " s pe c i es -s p e c i f i c " pattern o f a u n i v ers a l g ra m m a r w h i c h d et e r m i n es t h e d ee p s t r u ctu re o r g a n i z­ i n g m ea n i n g i n to s y n t a x o r g ra m m ar. These kern e l s e n t e n c es a re t ra n sf o r m ed i n l awfu l ways i n t o s u rfa c e st r u ct u re , o r s p ec i f i c h u m a n l a n g u ag es .

Perspe ctive Even thou g h Chomsky has provided a valuable service to our u n d erstan d i n g of learn in g by forci n g a reevalu a t ion o f the Skinnerian interpretations o f language acqu isition, h is theory can be attacked on two i m p ortant gro u n ds : 1 . Experimental tests of the i dea t h a t s u rf ace s tructure sentences are the end res u l t of a transforma tion from kernel sentences have provided confl icting results . Most studies h ave fou n d tha t reaction t i m es were longest when mul­ tiple transform ations were req u ired and s hortest for sentences assumed to reflect kernel sentences d i rectly . O ther factors, however, could h ave prod uced the res ults i nterpreted a s s u p p orting C ho msky. In m o s t s tu dies, the kernel sentences were s horter a nd easier to read . I t h a s also been fou n d that saying, "No," for a p o s itive sen tence takes m ore t i m e than saying, " Yes, " wh ile the opposite applies to nega tive sen tences . These types of factors could h ave i n fluenced the reaction t i m e measu re s (reviewed i n Tarpy and Mayer, 1 978) .

2 . Connection i s ts work ing i n the classical con d ition i n g tra d i ti on h ave not al­

ways ignored meani n g or semantic variables, as we saw in our rev iew of the research on sem a n t ic con d i t ion ing presented i n Chapter 8 . Even Skinner (1 969, 1974) accepts the i dea tha t m e a n i n g can be con d itioned and t h a t the responses of the "lingu i s t ic com m u n i ty , " a s well a s d i rect shap ing and rei n­ forcem en t , may influence l anguage. Many of t he concepts i n trod u ced by behaviorally ori ented learn i n g theorists have been experi mentally vali d a ted . O sgood (1953) s uggested t h a t words evoke i n ternal responses, wh ich he called m e d i a t i n g respon ses . He postulated t h a t these responses were subj ec t to t h e laws o f classical cond i t ioning. Th i s m e d ia tional model h a s b een s u p­ ported by research con d ucted by S ta a ts, S ta a ts , and B i ggs ( 1 958 ) , w ho fou n d

32-l

J\ I odenz C o n t en d e rs

that the mean ings of words coul d be i n fluenced by classical cond it i on i ng procedu res . The m ore rad ical behavi ori sm of t he 1950s h a s l argely been re­ placed by a behaviorism l ess opposed to cogn it ive variables; by a con­ tinued attack on obsolete ra d ical behav i orism, Chomsky may be g u ilty of beating a dead horse . I ronically, by a d d i ng to the p ressu re on behav i orists to become m ore accepting of cogn i tive and inn ate variabl es, Cho m sky m ay h ave helped the behaviorists to become capable som eday of provi d i n g m ore a dequate m odels of langu age acqu isi tion an d u se .

Chomsky too h as altered h is views b y payin g m ore a tten tion to mean i ng (semantic) variables rather than j u s t to syn tax variabl es . He h as also increased the role of evolution ary variables of the type described by the ethologis ts (whose work will be presen ted in the next ch apter) and h as descri bed language as a h u m an form of a "s pecies-specific" (inheri ted) behavi or . I n s p i te of the l ack of experimen tal val i d ation (or in most cases, i nvali dation) o f m any of h is cen tral conce pts, he rem ains a dom inant fi gure in the field s of psychol ingu istics a n d langu age learn ing (Pal ermo, 1978) . The n ext theory to be presen ted shares C homsky' s concern with inheri ted lo gical s tructures and cogn iti ve v ar i ables . M uch of Pi aget's work, however, has been experimentally val i d ated, and he is m uch more specific on the hows o f the acqu isition of knowledge . Jean Piaget: A Cognitive- M aturational The ory

O u tline of tlze Cog n i tive Theory a n d B asic Princip les Exp erience a n d 111a t u ra tion Much l ike M ontessori , Piaget developed a theory o f learn i n g which comb i ned a cogni tive emphasis w i th m a tu rational v ariables . P iaget gave M ontessori cred i t for advancing the concept that interes t a n d active effort go toge ther, an d that acti vi ty provided tra i n i n g for thought (Piaget, 1970) . Both saw the role of the environment as that of p ro v i d i n g nou ris hment to the child's develop ing b ra in, or, as expressed by H i lgard a n d Bower: The concept o f the environment no urishing hered ita ry potential lea d s to a d u al process in growt h : on the one hand, native poten tial is real ized u n d er the influence of en viron ment, so th at capa city to learn is a pro d u ct of this interaction ; o n the other h a n d , th is capac ity to learn i s a p plied t o a con tent o f learn ing that owes to the env iron ment, and to which natu ral a b i l i ty must be s u b servien t . In this M ontessori and Piaget are in agreen1en t . [ 1975 , p . 342] .

This realization of "native potential" depends upon the physical growth of the child's b ra i n , and thus the sequ ence in which a b i l i ties unfol d is as fixed as the s tages of en1 b ryonic and fetal developmen t . Th is is the basis for the famous "s tages" of Piaget's sys ten1 , wh ich are sim ilar to concepts such as "read i n g readi ness . " The extent to which a c h ild real izes the i n n a tely determ ined poten­ tial, however, is a functi on of exposure to ap propriate sources of s t imulation at the tin1e of the ch ild's reach ing the req u i red level of m atura tion . The rol e o f expo s u re , o r experience, i s not a purely p assive o n e . L i ke Skinner, P iaget b e -

J\1 odern Th eo ries with a Cognitive Emph asis

325

lieve d tha t an active child was a learn in g ch ild . Piaget sees such act i v i ty as tak in g three form s : 1 . Exercise: A type of con t i gu i ty learn i n g th a t does no t requ i re reinforcemen t . I t i s seen as en erg ized by the child ra ther than by environ m en tal s t i m u l i . Ex­ a m ples inclu d e the i ncreasing effi ciency, w i th pract ice, of k ick ing, head tu rn ­ i n g , a n d s o o n in i n f ants .

2 . Ph ysica l experien ce: A process of learn ing abou t the pro perties of obj ects,

u s u ally through m an ipulating them . It is the process by which the ch i ld learns t h a t metals are u su ally heavier th an wood or plastics, or tha t clay can be chan ged in s h ape . Through this process, the child gains the i n forma t i on needed to solve m ore abstract problem s . Letting the c h i ld learn through u n s tru cture d , d i rect physical experience w i th the elements of a problem is the techn i q u e of " discovery learn ing" pop u l arized by the gestalt theorists, and it is also s i m ilar to techn i q u es u sed in M on tessori schools . 3 . Logico - m a th em a tica l exp erien ce: A h igher type of learn i n g w h ich d epends u pon the spec i a l properti es of the subj ect-object i n teracti on , rather than the p hysical properti es of o bj ects, as in phys ical experience . Th i s is the process by wh ich a c h i ld d evelops abstract logical rules abou t the properties of ob­ j ec t s . Piaget labels these ru les "cogn i ti ve s tructures" (Philli ps, 1 969) and as such they form s trategy rules for solvi ng problems . They i nclu de such th i n gs as kno w i n g th a t o pera t i ons can be reversed a n d that o bj ects (as a l u m p of clay) can be res tored to prema n i p u l a tion appeara nce . O ther types of cogn i ­ t ions that are learned b y c hildren incl u d e knowledge o f order effects, classi ficat i on ru les, and o bj ect cons tancy .

In a d d i ti on to physical experiences with the environ m ent, the child also learns through soci al i n teraction s . M o s t of these soci al learn in g effects are l angu age - m e d i a ted (as h avin g a child's ego-centered view of the world d iscon­ firm ed by nega tive reaction s of adults a n d o ther c h ildren) . Piaget, however, sees logical operations as b ot h " deeper" t h an , a n d arising earlier than, langu age . A c c o rd i n g t o P i a g e t , e x p e r i en c e o f t h ree t y p es o f a c h i l d ' s a c t i v i ty i n teracts w i t h the m at u rat i o n a l seq u e n c e of b r ai n d eve l o p m e n t t o p ro d u ce a f u l l rea l i ­ z a t i o n of t he c h i l d ' s c o g n i t i ve a b i l i t i e s . The t h ree ty p es a re : ( 1 ) e x e r c i s e , w h i c h i s se l f-d i re cted a n d se l f- reward i n g , ( 2 ) p h ys i c a l m a n i p u l at i on o f o bj ects, a n d (3) l o g i co - m a t he m at ic a l e x peri enc e , w h i c h i s a n i n t e r n a l a bs t r a ct i n g p ro cess a risi n g f ro m t h e o t he r k i n d s o f a ct i v i ty .

Learning and develop1n ent

Like m os t cogn i t ively ori en ted theoris ts, Piaget d istingu ishes between b ehavior (wh at you d o , such as acting or thinking) and learn i n g . However, he also m ak es a d is t inction between learn in g and develop­ m en t . All i nferences about e ither learn i n g or developmen t are m a d e from obser­ vations o f o vert behavior. Thus, in P iaget's system, learn i n g and development are b o th hypothetical constructs, a n d their d is tinction from e ach o ther is vi tal (Wadsworth, 1978) . Piaget wri tes : The developmen t of knowledge i s a s pontaneou s process t ied to the whole process of e m b ryogen esi s . Em b ryogenesi s concerns the development of the

326

J\ 1 odern

Con tenders

body, b u t i s concerned as well w i th the d evelo p m e n t of the nervous system , and the developmen t of m en tal fu nction s . In the case of the developmen t of knowl­ edge i n c h i ldren , embryogenesis en ds only in adulthood . . . . Learn i n g p resents the o pposi te case . I n general, learn ing is provoked by s i tu a tion s-provoked by a . . . teacher, w i th respect to some d idactic po in t ; or by an external situa tion . It is provoked, in general, as o p posed to spon tan eo u s . I n ad d i tion , i t i s a l i m i ted process-l i m i ted t o a sin gle problem, o r a single s tructure . [ 1964 , p p . 7-8]

A n example of knowledge, in Piaget's terms, would be the seven-year-old child's s u d den realization that bending a wire does not change i ts len gth even though it looks very different . The child cannot h ave that reali z ation u n til h is or her b ra i n is s u ffici ently m ature , a n d the realization comes about s p on t aneously when the child m an i pu lates wire s . This knowledge provi des a new cogn i tive structure which the child u ses t o u n d erstand o ther relationsh ips in h is or her environmen t . K nowledge is thu s roughly the s am e as the kin d of generali zable understand i n g result i n g from " insightful" experi ences tha t K ohl er reported in h is c h i m p anzees . An example of learn ing, on the o ther h an d , wou ld be the chi ld's memorizati on of " two plus two equ als four. " The child may not under­ stand why " two plus two equ als four" or be able to generalize this rule to n ew combinati ons of n u mbers . He learns this rule becau se the teacher re inforces i ts memori zation . Learn in g i nv olves u sing i ntellectual structures i n the acqu isi ti on o f a skill or of spec i fic information . Learn i ng may i n volve form i n g memories through associati on or through rote p ractice (wh ich can be overt in learn i n g skille d acts, o r covert i n verbal learn i n g) , or i t may involve learn i n g with com­ prehension . Learning w i th com prehensi on i nvolves an interaction between d e­ velopment (and knowledge) a n d learning; we will now d iscuss some of the mecha n isms of this i n teraction . P i a g e t d ist i n g u i s hes k no w l ed g e , w h i c h is s p o n t a n e o u s a nd i s rel ated to t h e m a t u r i n g b r a i n ' s beco m i n g a b l e to " k n o w " so m e t y p es o f r e l ati o n s h i ps, a n d l e a r n i n g , w h i c h is p rovo ked b y ot hers a n d s p e c i f i c to t he p a rt i c u l a r m ate r i a l l e a r n e d . K n o w l ed g e i s a g en e ra l i z a b l e u n d e rs t a n d i n g o r a s h i ft i n a way of t h i n k i n g abo u t so m et h i n g . --�-� �--

The

me chanisms

by

w hich

c og 1 1 1 t1 v e

s t r u ct u res

g ro 1u

and

a re

a l tered

While learn i ng through exp erience is sin1 ilar in P i aget's t heory to the mech­ a n isn1 s d iscussed in m os t cogn i ti ve theories, P i aget has added a new type of m ore complex learn ing n1echanism . This mechan ism is that of equilibration, which he sees as the fundamental factor in develo pment a n d necessary to coor­ d i n ate matura tion, p hysical experience of the environment, a n d social experi ­ ence of the env ironment . It is an inn a te need for b alance b e tween the organism a n d i ts environment, as well as for balance wi th i n the organis m . I t is a p rogres­ sive, self- regula tin g process and has powerful moti v a ti onal propertie s . E q u i l i b ­ ra tion is the p rocess responsi b le for i n tellectu al development at all matura ti onal stages and is also the mechanism by which a child m oves from one develo p -

Modern Th eories with a Cogn itive E mp h asis

327

mental stage t o t h e n e x t . Rou ghly, i t is a dyna m ic s hift by the c h i l d i n response to situations or stimuli which d isconfirm existing i nternal schemata (cog n i t i ve structure s, or concepts, whic h filter a n d process i nco m i n g p erceptions) . D iscon ­ firmation, o r dise q u il ibration, leaves the child in a state of i m b alance a n d p ro­ vides the motive to restructure his sche m a ta . New sche m a ta may p rovide new i ntellectual abilities which are qualitatively d ifferen t from p revious a b ilities. The p rogre ssion of i n tellec tual develop ment from d e velo pmental stage to devel­ o p mental stage is d e fine d by the new sche m a ta so acquired as a result of d is­ e q uilibration a n d the p rocess o f equilibra tion (motive to restore b alance) . To u nderstand how d isequ il ibration occurs, i t is n ecess ary to understa n d two a d d i tional P i agetian ter m s : assimilation ( " fitting i n " of n ew d a t a into old schemata) an d accommodation ( the restructuring of schemata to form e ssentially n ew sche m a ta) . A ssimilation is the normal p rocess by wh ich an i ndivid ual i ntegrates n ew d a ta with p revious learning . Like the gestalt theorists, Piaget sees new p ercept ions as occurring with in a lawful preexisti n g framework. The child d evelop s cog n i t ive categories ( schemata) , or m en tal p igeonholes, in which to s tore n ew information . W hen som e th in g fails to fit preexisti n g p igeonholes, then n ew p igeonholes must be created . The process of alterin g the basic catego­ ries of thought, or of m o d i fy i n g som e activity because of environ m en tal d e ­ mand s , is accomm od ation , a n d the end resu lt of t h e alteration is e q uilibration , w h ich u s ually l ea d s to a better a d aptation to the environm en t . Thus, by suggest­ ing that the processes of learni n g , p erception , and t ho u g h t all show q ualitative changes as a result of the interaction between d e velopmen t an d experience , P iaget i s i n disagreement ( disequilibri u m ?) w i th t h e gestaltists' i de a of fixed " laws" g overni n g learn i n g a n d other behaviors . P iaget's internal organi z i n g principles (which are similar in many ways to the gestalt laws) , o r schemata, change as a function of m a tu ration a n d experience into n ew cogni t i ve struc­ tures, or rules for p rocessin g i n forma tion . O nly the functions (equilib ration , accomm o dation, a n d assimilation) continue to operate throughou t the child' s develo p m en t . While Piaget rej ects the i de a that the cogn i ti ve categories (schemata) , or m en tal structures, are fixe d , he does m a in tain that the functions (basic m en tal processes) are not only i n variant b u t are inna tely determined (Phillips, 1969) . These funct ions i nteract in d i fferent ways w i th d i fferent sorts of experience s . For example, when c h il dren i mitate, accomm od ation is ascendant o ver assi milation . The child who i m itates older m o d els is behavin g in new ways which u s ually reflect the m odels' more h ighly d eveloped sche m a ta . When children play, as­ s i m ilation is dominant. Piaget says children play simply to exercise responses. This has the effect of stabilizing thei r existing sche m ata, thu s making them e asier to recall and enhancing further learn i n g (Wad sworth , 1978) . This is similar to S al tz' s i d e a of i ncreasing t he b o u nd ary s trength of concepts through practice . Behavior is considered to be m os t a d ap t ive when these two functions are i n b alance, or e q u ilibrium, b u t p erfect balance shows gaps a n d i nconsistencies i n existing cogni tive s tructures ( disconfirmation) which produce n ew s tates o f

3 28

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Con tenders

d iseq u ili bra ti on . Th is is because p erfect balance is balance to an exis ting set of circumstances; when c i rcumstances change, the existing balanced schem ata are no longer adequ a te . For example, the simple schema of j u dging the amount of l i q u i d in glasses by the ir height m ay be perfectly adeq u a te for the preschool ch i ld (who assi m ilates informat ion about new containers i n to th is schemata witho ut nee d i ng to change the schem a through accommodation) b ut i nade­ qu ate i n a school situation i n w h ich more p rec ise measurement is req uested by teachers . Though the process of organizat ion and reorgan iza tion is continu ous, the results of this process are d iscontinuous and quali tatively d i fferen t at d i fferent ages . This d iscon t i n u i ty form s the basis of P i aget's developmental system, i n wh ich a series of qualitatively d i fferen t stages, organ ized i n to periods an d s u b ­ periods, occur i n the s a m e order for all ch ildren . The periods are classi fied accord i n g to the h ighest types of schemata a va ilable to the c h i l d , and some earl i er cogn i tive structu res m ay persis t even when a child has advanced to a h igher stage . Although Pi aget g ives the ages a t wh ich c h i ldren can be expected to be i n a given stage, he recogn izes that d ifferen t ch ildren will advance to a g i ven stage a t somewhat d i fferent ages . S ince t h is is intended as a text about learn ing, we will only summarize the stages and subs tages . Note that in sug­ gesting that the basic mechanisms of inform ation processing and learn i ng ( the schem ata) change w i th development and experience, P t aget has suggested that a sin gle set of learn i n g laws is i nadequ ate to account for the c h i ld's reactions from early infancy to early teenagehood . P i ag e t i d e n t i f i es t h ree c ri t i c a l p ro c esses o r f u n c t i o ns w h i c h a re i n vo l ved i n l e a r n i n g a n d t he acq u i si t i o n of k n o w l ed g e : ( 1 ) eq u i l i b rat i o n , t h e m o t i ve to see k b a l a n c e ; (2) assi m i l at i o n , ro u g h l y l i ke s t i m u l u s g en er a l i z a t i o n i n f i tt i n g n ew i n p u ts i n to e x i st i n g s c h e m ata ( c o n c e p t s , o r r u l es for p rocessi n g i n f o r m a­ t i o n ) ; a n d (3) a c c o m m o d at i o n , o r form n e w s c he m at a ( as i n d is c ri m i n a­ t i o n l e a rn i n g ) .

The O evelop nz en tal S ystenz Rela ted to Learning * Sensorinz o tor period (0-2 yea rs )

D u ring the first few weeks after b i rt h , the i n fan t res ponds on the basis of innate sensorin1 o tor schen1 a ta (reflexes) . The infant's first type of learn ing is discrim i n at ion learn ing; for exam ple , the i n fant becomes able to d iscrim i n a te a 111 ilk - producing n i pple fron1 other o bj ects tha t he n1 ouths in exercisi n g his suck i n g reflex d u ri n g the second s tage (Wadsworth, 1978) . As n1 ore sensory experiences are assim ila ted, ol d schemata become i ntegrated into habits and percep t i ons through accomm odation . Because the

*

A s t i m e peri ods for the d i fferen t stages of development vary fro m c h i ld to ch i ld , the ages g i ven are averages . Tra n s i t i ons fro m stage to st age may be gradual a n d are a ssumed to be motivated by the d iseq u i l i br i u m proce ss, d iscu ssed earlier , w h ich reflects the aversi ve effec ts of d iscon firm a tion .

M odern Theories with a Cog11itive Emph asis

329

i n fant's a tten t ion is centered on i ts own body an d not on external obj ects, these reactions are called prim ary. Because they are endlessly repeate d , they are called c ircular. This s tage o f i n tegrating innate behavior w i th experience lasts from the first to the fo urth mon th . The second s tage is secondary c ircular react ions (fo ur to e igh t m onths) . These reactions, such as an i n fant's shaking a rattle to hear the sou n d , are repetitive a n d self-reinforcin g . D uring th is stage , acts become in ten tional, primary s tage schemata are amalgam a te d , and the child searches for o bj ects th at are s u d d enly removed (obj ect permanence) . D uring the th ird stage ( e igh t to twelve m on ths), the child is able to fin d obj ects h i dden beh in d barri ers a n d to separate ends from mean s . When behav­ iors (means) occur w i thout ends, P iaget labels the behavi or " play" ; when they are related, P iaget l abels the beh avior "pro blem solvin g , " wh ich m ay be a trial- a n d - error process . While m ean in g an d learni n g in the second stage were define d in terms of m o tor activity , sym bol ic m eaning ( thought, or cogn i tions) appears in the fo urth s tage . At th is time the infant begins to u nderstan d causal­ i ty (or contin gencies between ends and m eans) and may wait for an a dult to bring h is bottle rather than conti n uin g to scream u ntil it is i n h is mouth . Al­ though the typical one-year-old may say a few words, such as " daddy" or " m ommy, " these so unds are not true lan guage b u t i n s tead are instrum en tal responses wh ich are reinforced by parental attention or other consequ ences . S tage 5 , tertiary c ircular react ions, extends from 12 to 18 month s . True i m i ta­ tion ( m o d el i n g) appears as a learn i n g m echan ism for acco m m o da tion, although the child continues to depen d u pon direct experience as h is basis for assimila­ tion . The child b egins the process of decentration, or a reduction in egocentric­ ity ( the youn ger child is assumed to see h im self as the center of the u n iverse) . S tage 6 is a p erio d in wh ich the child begins to apply fam il iar schemata to new situa tions, as in stage 4 (generalization of concepts), in order to m o d i fy familiar schem ata to fit new situ a t i ons, as in stage 5 ; in a dd i tion, he begins to invent new m eans through combinations of schemata ( in sight learn in g?) . Th is last process is labeled by Phillips ( 1969) as reci procal assim ilation of schem ata . In a d d i tion , object p ermanence now extends in time (as when a blanket is put away for a few d ays) rather than j us t when obj ects are h i dden behind barriers, as in e arl i er s ta ges . M o deling can now occur w i thout prel i m i n ary tri al - a n d - error behavior an d after the m odel has van ishe d (as in play) . Pi aget's s u ggestion that i m itative, or m o deling, behavior a p p ears in a fixed d evelopmen tal seq uence wo uld seem to have im portant impl ica tions for Ban dura's theory of modelin g .

Preopera tional period (2 -7 years )

The preoperational p erio d is charac­ terized by the development of intern alized act i ons tha t are reversible, in tha t the ch ild can think of, or see, an action a n d then th ink of what would happen if that action were to be un done . D uring th is p eriod, the chil d is no longer l i m i te d to an o vert S-R, or trial- and-error, type o f learn ing but instead begins to show m ore a n d m ore cogn i tive learn i n g . Wadsworth ( 1978) d iv i d es th is perio d into the Egocentric Stage ( two to four years) a n d the I n tu i tive Stage (fi ve to seven years) . D uring this p eriod, the child p erform s m en tal experimen ts i n wh ich he runs

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th rough the symb ols for events as if he were actually partic ipating in the events . This leads to one - way (egocentric) th inking, as illustrated i n the following exam ple : A fou r-year-old subject i s aske d : "Do you h ave a brother?" He says, " Yes . " "What's h i s name?" "Ji m . " " Does J i m have a brother?" "No . " [Phillips, 1969, p . 6 1 ]

As can be seen, the preoperational ch ild's th i n king is no t reversi ble . The c h i ld , however, is gaining skills that will eventually result in this new tool of th in kin g. While the sensorimotor ch i ld was "egocentric" in his or her overt actions, so the preoperational child shows symbolic egocentrici ty , or centration, while decenterin g actions . The preoperational ch i ld begins to show classifica­ tion skills (being able to group events i n to concepts, or schemata) , although the h ierarchies thus generated m ay be very d iffere nt from those of ad ults . In general, the categories ten d to be m ore narrowly defin ed and b roader in scope (havi ng fewer defin ing attributes per category and having fewer categori es) . Though learn i n g can now som etimes occur th rough cogn i tive mechan ism s, these are pri m i ti ve types of cogn i ti ve processes in wh ich thought is d o mi n a ted by env i ­ ronmental stimu l i . I n t h e f i rst (senso r i m ot o r) p e r i o d o f P i ag e t ' s d eve l o p m e n t a l syst e m , t h e c h i l d p ro g resses f ro m u n i n t en t i o n a l exercise of ref l exes. t o d i s c ri m i n ati o n l e a r n i n g a n d t ri a l - a n d -e r ro r l e a r n i n g , t o t he be g i n n i n gs of s y m bo l i c t h i n k i n g a n d u n ­ d e rst a n d i n g of c a u s a l i ty . I n t h e s e c on d ( p re o p erat i on a l ) peri o d , t h e c h i l d d e­ c e n t e rs a ct i on s a n d sh ows p ri m i ti v e c o n c e p t u a l b e h av i o r . T h i n k i n g i s s t i l l e g o c e n t ri c o r i rreve rsi b l e .

Concre te o p era tions period (7- 1 1 yea rs)

During th is per i o d , the child's thinking becomes decen tered and truly reversi ble . There is one im portan t l i m ­ i tation to this a b i l i ty; that i s the child's need to see the operation o r perform i t in order to reverse i t men tally . Du ring th is period , the basic logic o f mathematics develops as a series of d isc rete logical schemata . Before the child has developed the fu nd amental concepts of num ber, he may men1 orize , say, 1 + 1 2, through ro te association mechan isms . Th is type of learn in g is considered to be isolated from mental structu res, or schemata . Once the concepts of num ber are devel­ o ped , the learn ing of 1 + 1 2 becomes in tegra ted with mathematical schemata, and learn i ng wi th co m prehension occu rs (Wadsworth , 1 978) . Ano ther qual i tative change i n the ch ild's lo g ical a b i l i t ies is the understan d­ i n g tha t changing the appearance of so meth i n g m ay not ch ange i ts other proper­ t ies (conservation) . There are several types of conservations, and the c h i ld's skill in understan d i ng e ach (and perform ing the correct acts) tends to appear in a sequ ence beginning with conservation o f quan tity an d end i n g wi th conserva­ tion of volum e . Conservation of quantity is shown in the water j ar experi ments in wh ich two j ars of equal appearance, contain ing e q u al amounts of flu i d , are =

=

33 1

M o denz Theo ries with a Cogn itiv e Emph asis

� 1

---

r-

-

-

- ,

--

S i t uation 1

,,- -

-

'>

Transformat ion

.---

S i tuation 2

Fig u re 1 1 . 1 Con serv_a tion of qu a n tity w i th flu id. Situ a tion 1 shows two con tain ers of equ a l size, b efore th e appeara n ce of t h e flu id is tra nsform ed b y p o u ring i t in to th e tall, thin co n tainer. Situa tion 2 is after the p o u ring . A yo u ng child m a y wa tch th e po u ring and still give incorrect respon ses . If th e wa ter in th e tall, thin con tainer is th en po u red back in to th e wide con ta i n er, the p reopera tio n a l ch ild will retu rn to h is Situ a tion 1 response th a t "bo th h a v e th e sa m e . "

presented to a ch ild . The flu i d from one j ar is then p oured into a tall, thin b eaker or graduated cyli n d er and the child is asked wh ich container now "contains m ore flu i d . " The p reoperational ch ild e m i ts the s u rprisin g answer tha t the tall, thin container contains "more flu id . " This illustrates i rreversible thought. The operational child says, "The same, because if you p oured them b ack they would look the same again . " The experimental situ a t i on is shown in Figure 1 1 . 1 . S uccessful conservation of quanti ty is a prereq uisite for the development of a true concept of n um ber, wh ich i n turn is a prereq uisite for learning arithme­ t ic "with comprehension" (Wad sworth , 1978 ) . Th is illustrates the principle that logical m aturation is h i erarch ical (has a necessary sequ ence) . While the ch ild in the period of concrete operations m ay correc tly solve conservation problems, his th inking is labeled concrete because i t s t ill requires direct sensory experience . If asked to i dentify the reason why the l i q u i d is "s till the same" after the transfor­ m ation, the child will be u nable to abstract the general principl e . Th is ability will not appear un til the fin al s tage of logical d evelopment, or the p eriod o f formal o p eration s . Behaviorists a n d other non-Piagetian learn ing theorists h ave attempted to explain away the results of the conserva t i on experiments by suggesting that m otivational variables could be involved . When the experimenter asked a ch i l d , "Wh ich glass h a s m ore now?" h e or she m ay have b een creating a demand in the ch ild's m ind to i d en tify one glass as h aving " m ore . " S ince water is the flu id in the glasses in m o s t of these experiments, the child d i d not really care about m ak ing a carefu l j u d gm ent and so reacted to the demand characteristics of the situation . The author, however, has seen the same results when a p reoperational child is told tha t both con ta iners con tain lemonade or som e o ther tasty flu i d and tha t the c h ild can drink the contents of the container holding " m ore . "

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J\ l o den1 Con t en d ers

Critics h ave also suggested that Piagetian researchers may have u ncon ­ sciously shaped (gu ided) the ch ildrens' responses . Sigel, Roeper , and H ooper (1965) have presented a summ ary of the ir a ttempts to sh ape conservation in preoperational ch ildren . They fo und th a t even though a c h ild h aving the neces­ sary prerequ isite logical abilities could be tra ined to conserve, such tra ining was ineffective with non - " transitional" ch ildren . In other words, m otivational and training variables only work on ch ildren at a level of developmen t very close to that at wh ich they would naturally o btain conserva t ion . They found that pre­ liminary tra in i n g of the prerequ isite abilities (such as reversi b ility and decentra­ tion) a ided in concept acq u isition . Th is work essent ially s u pported Piaget's developmen tal model . Other research showing that environmen tal variables can speed up the acqu isition of s pecific conservations has been conducted by Wadsworth, Banks, and Kraem er ( 1975, reviewed in Wadsworth , 1978) . They fo und th at " d iseq u i l ibrium trainin g , " wh ich consis ted of having the experi­ menter ask children to "review and reconsider" the ir erroneous results, was followed by sign ifica ntly faster acqu isition of conservation of length . In support of Piaget's view that development is ultim ately dominant o ver d irect teach ing, however, a one-year followup uncovered no d i fference between tra ined and untrained (control) s u bj ects . D u ri n g t h e t h i rd ( co n c rete o p erat i ons) peri od , t h e c fl i l d b e g i n s t o d is p l ay s i g n s of k n o w l ed g e t h at o pe rat i o n s w h i c h h e o r s h e sees c h a n g i n g t h e a p ­ p e a r a n c e of so m e s u bst a n c e o r o bj e c t c a n b e reversed . T h i s type o f u n d er­ s t a n d i n g is seen as q u a l i t at i v e l y d i fferen t f ro m m e m o r i z a t i o n of i n f o r m at i o n a n d i s best s h o w n b y con servat i o n e x p er i m en ts . D u ri n g t h i s s t a g e , d i rect sen so ry e x p e r i e n c e i s n e cess a ry t o so l ve t he m a n y types of c o n serv at i o n p ro b­ l e m s . Con se rv a t i o n d e p en d s u po n m at u rat i o n .

Fonna l opera tions p e riod (1 1 -1 5 y e a rs )

The fin al stage o f lo gical develop ­ ment is that of formal operations, or the abi lity to use i n ternalized abstract o pera tions based on general principles or equ ations to pre d ict the effects of operations upon obj ects . This abil i ty appears in children between 11 and 15 years of age . Such a ch ild is s a id to be fully operational . Also i nvolved is a compl etion of the decentra tion process to the p o i n t that th inking and problem solvi n g can take place in a purely abstract framework wi thout ends of obta i n i n g food o r sat isfying o ther needs ( Bruner, G oodnow, and Austin, 1956) . Because the teenager is able to form ulate hypotheses about th i ngs which may not be ava ilable for n1an ipulat ion, truly in ternal " trial and error" becomes possible , as well as n1ore cogn itive "rec iprocal assimilations of schen1 a ta. " The differences i n thinking a n1ong children in the three m a i n periods of develo pmen t (preopera tional, concre te operati ons, formal opera tions) can be demonstrated by the "specific gravi ty problem . " I n this problem the child (or the adolescent) is presented w i th a series of obj ects (wood, iron , and other 1na terials) an d is asked why each e i ther sinks or flo ats . A correct answer would be in terms of the vol ume of each o bj ect in rel ations h i p to i ts we igh t . Because the preopera tional c h ild's th inking is controlled by h is re presentations of the

M o de rn Th e o ries with a Cogn itive E m p h asis

333

world , he or she blithely i n vokes a s p ecial c ause for each even t . The child in the p eriod of concrete o pera tions, l i m i ted by h is or her concern for orga n iz i n g the data of h is or her senses, will usually try to classify the obj ects from heavy th ings (iron bars wh ich always sink) , to somewh at heavy things ( aluminum pan l i ds which sink only when filled with water) , to light th ings (wood) . New o bj ects are then assi m ilated into these establ ished categories (as keys sink beca u se, "They m u st b e i ron also" ) . Though the thinking of the child in the p eriod of concrete o perations is orderly, i t is based u pon classifica tion sys tems wh ich incorporate only one phys­ ical d imen sion (we ight, in th is exam pl e) . The child in the perio d of formal o perati ons is able to coord inate informa tion about two d i m ensions (weight a n d v ol u m e , a s in ferre d by the volume of wa ter displ aced b y the flo ating obj ect) a n d t o arrive at a conclu sion a b o u t proportion s . Th is type o f th inking reflects the ability to th ink conceptually , or to perform operations on operations (which Piaget calls secon d - order operations) , rather than j ust operations with obj ects . Subj ects in the peri od of form al o perations form ula te hypo theses about problems to fill in the gaps in their understan d i n g . These subj ects can manipu ­ late one variable systematically wh ile hol d i n g others con stan t , wh ich i s the classical method of experi mental science . These interior m an i p ulations of hy­ potheses represen t internal ten tative accomm odation , or the form i n g of a series of schemata until a schema is formed which fits all the a dolescent's d ata . Thus, the formal o perations subj ect is able to depart from real i ty b u t i n a l awful way wh ich reflects his or her apprec iation th at d irect sensory data is only a s u b set o f a l arger set of possi b i li t i e s . This departure from real i ty allows this s u bj ect to form abstract laws wh ich predict the properties of obj ects not yet encountere d . Phillips (1969) , however, notes th a t the form al operations subj ect may fail to d istingu ish b etween h is or her h yp o theses and the social or physical u n i verse to wh ich they are applied . Th is type of egocen tr ic thinking m ay lead the a dolescen t to conclude that because h is or her own ideas are logical, others should fol low the same logic . Th is i dealis t ic egocentrism is reflected in the types of m oral j u dgm en ts m a d e by the form al operations s u bj ec t . B ecause moral j u dgmen ts illu strate the changes of th inking tha t occu r o ver the p eriods, let u s now briefl y exam ine Pi aget's d evelopm en ta l sequence for moral development . D u ri n g t h e fo u rt h ( fo r m a l o pe ra t i o n s) peri od , t h e p e rs o n b e co m es c a p a b l e o f g o i n g beyo n d i m m ed i ate s e n so ry ex p e ri ence a n d c a n t h i n k abst ract l y , o r p e rf o r m o perat i on s o n o p e r at i o n s, t o a r rive a t h i g he r-ord er s c h e m a t a , o r g e n ­ e r a l p red i ct i v e h y p o t h eses o r l aws.

Piaget's theory of n1ora l develop n1 en t

Pi aget has proposed that the two b a s ic operations involved in the develo pmen t of logic (reversibili ty and conser­ vation) h ave thei r affective cou n terparts . M orality is defin ed as the system o f rules t h a t regulates interpersonal beh avior on a rec i procal basis, o r the conserva­ tion of feelings (as in reci procatin g friendly behavior from ano ther person) . Preoperation al ch i ldren ( those u n d er seven years of age in most cases) are only able to think in one d imen sion ; their though t p atterns are self-centered or

J\ l odenz Con tenders

33.J

egocentric . Thus, they may classify people as behaving morally solely on the basis of persons behaving like them selves . The ch ild in the s tage of concrete operations is be tter able to u se the data of h is or her senses (what are h is or her group's norm s) and to th ink in two d i m ensions (how he or she feels about som e thing and how he or she should behave towards others) . Th is child h as advanced beyond the selfis h m oral j u dgm ents of the preoperational child to m aking m oral j udgmen ts b ased on h is or her vi ews interacting with p eer-grou p and adult norm s . I n this stage, m oral j u dgm ents a r e "conventional . " I n the last p eriod o f moral development, the p erson is able to m ake m ultid imen sional moral j udgments b ased o n abstract p ri nciples* (or p erform opera tions on o pera­ tions) wh ich m ay not con form to group norm s . M oral thinking in this last perio d is sim ilar t o the lo gical thinking of the formal operations person (Biggs, i n Varm a and Williams, 1976) . The developmental system for m oral j udgmen ts d iffers in two important respects from the developmental system for logic an d th inking . First, p rogress is slower, with children in the p eri od of concrete o p erations still showing egocen­ tric, or preopera tional, moral th inking an d adolescents typically showing con ­ ventional, or concrete opera tions, moral th inkin g . A b s tract, or 0postconven­ t ional, " moral th inking u sually does not appear u n til the m iddle twen ties and m ay never appear at all . Second, the type o f moral j udgments m ade are much m ore influenced by modeling and direct re inforcem ent th an the m ore innately programmed sequ ence of develop m ent of logical th inkin g , in general . As K ohlberg has shown through research on h is extension of Piaget' s system, college-age stu dents m ay show patterns o f moral j u dgmen ts ranging from very egocentric to very abstract (revi ewed by Biggs, in Varma and Williams, 1976) . H e has also found that the s peed w i th wh ich p ersons progress through the sequence of moral d evelopment is influ enced by o ther variables, such as soci al class an d peer- group standards . This suggests tha t moral d evelopment is m uch more controlled by learning (not bi ological maturati on) than is logical development. P i a g e t has a l so p ro p osed a d eve l o p m en ta l seq u e n c e f o r m o r a l d eve l o p m e n t , p ro g ressi n g f r o m p re c o n v e n t i o n a l e g o c e n t r i c u n i d i m e n s i o n a l m ora l c o n ­ c e pts . to c o n v e n t i o n a l so c i o m et r i c b i d i m e n si o n a l m o ra l t h i n k i n g , to p o s t c o n ­ ve n t i o n a l a bst ract m u l t i d i m e n s i o n a l m o ra l s c h e m ata. T h is seq u en c e i s m o re v a r i a b l e a n d i n f l u e nced by l e a r n i n g t h a n i s t h e seq u e n c e for t he d eve l o p m e n t o f l o g i c , i n g e n e ra l .

Persp ective Piaget has develo ped a theory o f learn ing and cogn ition stressing the epis temol­ ogy, or structure, of logic . This theory i ncludes the idea that innate fac tors, such as the functions of assim i la tion and accommoda tion, act toge ther wi th en­ vironm ental i n fluences to change cogni tive s tructures in qualitative ways, in accordance with an innately determ i ne d develo pm ental order . This theory , *

Such as soc i a l j u st ice .

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then ( is n aturalistic, interactionis t- m a tura tionist, cogn itive , and s tructuralist. Althou gh Piaget's m ain aud ience among p s ycholo gists has been developmental p sychologists, his theory tha t the m echan is m s o f learn ing depen d upon devel­ o pmen tal level and h is suggestions for teac h in g an d prov i d i n g optimal learn i n g environmen ts* q ualify h is t heory a s a learn ing theory . Taking seriously Piaget's o pposi tion to " direct" teac h in g , on the grou n ds that lectures and rei n forcement of selected behaviors develop cogn i tively iso­ late d rote m e mory rather than integrated "knowledge , " m an y teachers a n d some schools (Pacific Oaks experimental pre- and primary school in P asadena, C aliforn i a is a good example) h ave tried to incorporate Piaget's ideas in their teaching progra m s . In p art, this m ay reflect m any educators' disl ike of behav­ iorist approaches to educatio n . A rea dable guide to P i agetian applications has been provided by Barry Wadsworth in h is text Piaget for the Classroo m Teacher ( 1978) . Techn i q u e s of surprise (as in the d ise qu ilibrium trai n i n g previou sly mentioned) and inqu i ry tra ining (similar to the ges talt techn ique of d iscovery learn i n g d iscu sse d in Chapter 5) h ave been fo u n d u se ful in motivating children to act on obj ects and events . This, of course , is t he result of d isconfirmation of the child's pre d ictions. Piage tians m ake a distinction between three types o f knowle dge : physical knowledge (which children learn through the ir activi ty with obj ects, such as u n successfully trying to b urn stone ), logico- mathem atic al knowledge (which comes from the child's actions impose d on o bj ects, as when the c h ild learns about n u mber from counti n g collections of obj ects) , and so cial-arbitrary knowl­ edge. Only soci al-arbi trary knowledge should be taught and re inforced in the " d i d actic - lecture metho d " m o d e . The child is seen as b e in g taught the first two types of knowledge by the o bj ects themselves (much as M on tessori's d i d actic m a teri als were i n ten ded to be self- teaching a n d self- re in forcing) . To interfere with the child's spontaneous activi ties is to retard h is acqu isition o f true " knowledge" of the first two types . Letting the child be wrong in h is pred ictions is seen as prov i d i n g the motivation for accomm o dation . Wadsworth ( 1978) also s uggests that becau se the schemata of o ther children are more likely to be sim ilar to a gi ven child's lo gical structures, com m u n ication about logico-mat hematical a n d social-arbitrary knowledge is often m ore effi ­ c ient be tween children of the same developmen tal level than b etween ch ildren a n d a d u lts . This suggests extensive u se of "peer teaching" techn iques . Wadsworth does concede that when rapi d behavior change is necessary, behav­ ior m o d i fica ti on procedures m ay be appropriate , as long as t he child is devel­ opmen tally advanced enough to learn from the m . He states that such behavior changes s hould not be confused w i th true knowledge or reason i n g . This focus on the active , in ternally d irecte d , organizin g functions o f learners is also to be fou n d , in m ore m echan istic language, in the n ext theory to be reviewe d .

*

He su ggests t h at every t i m e a teacher t eaches som et h i ng , c h i l d ren are preven ted from d iscov­ eri n g i t for t h em selves. Th us, cla ssrooms s hou ld be fu ll of o p portu n i t i es for p h ysical m a n i pulation of o bj ects, a n d teac h i n g s hould be d i rected towards su gges t i n g to c h i l d ren t h a t they try to fin d out w h a t would h a p pen i f so m e t h i n g is c h a n ged or m a n i pu la ted ( P h i ll ips, 1 969) .

33 6

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I nform ation- Processing Approaches to Leaming and Memory

The i n formation - processing approach to learn ing ori gi n a ted from several sources . E llis (1978) s uggests an i n fluence of the ges talt theory of mem ory, which s tates that the ways organ ism s actively organ ize their percep tions are reflected in how they organ ize the i r memori es . Norman ( 1970) d istingu ishes three m a i n i n flu ences reflected in curren t informa tion- processing theories : ( 1 ) ma the ma tical learn ing theories of the types first proposed by Estes, Hull, an d Spence, (2) signal (atten t ion) d etection theories, w h ich contributed the suggestion th at learn ing is a m u ltistage process begin n ing wi th selective atten tion an d end ing with long- term memory traces, an d (3) compu ter models, wh ich were h i ghly i n d ebted to the concep t of cybern e t ics i n troduced by Norbert Wien er . Computer-model theorists contributed the i dea that processing b y perip heral processin g devices precedes processi n g by the cen tral compu ter, the i dea that temporary working memories i n teract w i th m ore lastin g core s torage memori es, and the i dea that memoriz ation is a fu ncti on of the programs (or rules a n d strategies) involve d . Th u s, mem ory , for the i n form a tion- processing theorists, i s much more than j ust someth i ng t h a t med i a tes be tween s t i m u l i and response s . We have already d iscu ssed the fu nctionalist S -R association approach to human verb al learn i n g ch aracterized by a nonneurological environ men talist orien tation in wh ich mem ory is simply the conseq u ence of the learn in g process . By contrast, information- processing theories often d iscuss possible neurological mechanisms (wh ich will be explored fu rther i n the d iscu ssion of Pribram's neurological information- processing theory in Chap ter 12) w h ich m ay be in­ volved at each of several of the s tages of learn i n g , or they suggest analogies w i th s tages of compu ter in form ation process i n g . As w i th con1 p u ters, human learn i ng i n volves th ree types of processes : encoding, storage, and retrieval (Ellis, 1978) . L i ke the gestalt theorists, the inforn1 a ti on- processi n g theoris ts see perce ption , learn ing, an d men1 ory a s reflecting a processing con tinuun1 u n i fied b y comn1 on organ izational princ i p les opera ting w i t h in act ively organ i z in g organ ism s . The portions of th is con tinuum explored in depth by inforn1 a ti on- processing theoris ts incl u d e : atten tional mech an is n1 s (selec tive attention), storage at the level of the sense organs and lower brain areas (sensory in forn1a tion s tore , or S I S) , working or i n1 m e d i a te n1emory (short- tern1 men1 ory, or STM) , mechanisms for transferring im med iate n1en1 ory into long- tern1 s torage (consol i d a ti on) , and fin ally , in ech anisms for retrieving inforn1 a tion fron1 long- tern1 mem ory ( LTM) . L i ke Spence and Bandura , an d li ke the cogn i tive theorists, the information-processing theoris ts d is tingu is h be tween wh a t may be learned (de­ fin ed as what is stored in pern1anent n1 en1 ory) and wh a t w i ll be performed (or retrieved) in tes ts o f h u n1an n1 e1n ory . Failure to dem ons tra te s tored knowledge in perforn1ance is seen as also invol v i n g a fa ilure of retr i eval n1 ech an isms ra ther than forgetting, as postulated by the S-R assoc i ation is ts . I t is the ex pl icit attem pt to distingu ish s torage and re trieval using a concep tual langu age borrowed from co m p u ter tec hnology that characterizes inform ation -

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p rocessing a pproac hes . Retrieval, m ean i ng the b u si ness of getting t h ings o u t of s torage, takes on a special i m p ortance for those psychologists who emphasize i nformation-processing a pproaches . The focus i s m ore on re trieval than on s tor­ age w i th these a pproaches becau se retrieval mechan isms are viewed as the key to u nlocking memory . [ Ellis, 1 978 , p . 801

Let us now review each of the stages of learn in g as classified by Donald N orman (1970, 1976) .

The S tages of Lea rn ing Atten tioll The idea tha t attention is a v i tal p art o f the learning p rocess has a long h istory . To a i d orators i n cultivating reli able memories, the Romans wrote a text (Rlzetorica ad He renniu m ) on the subj ect of tra in i n g memory . The first rule given in that ancient text was " Pay attention" (Norm an , 1 976) ! First Pavlov ( 1 960) and then Sokolov ( 1963) cond ucted research on the attention- related orienting re flex (OR) and concluded that con d i t ion ing was i m p ossible u n til the OR had been elic ited . The ges talt the ory d ifferen tiating figure as what was atten d e d to and learne d , fro m ground , focused on selective attention as a pri ma ry v ariable i n learning. The problem o f selecti ve a ttention , rather than random responsiveness to environmental sti m u l i , is illustra ted in the cocktail party problem i n vestigated by E . Colin C herry (in Norm a n , 1976) . Consider the situ ation faced by someone at a large party. Several conversations m ay be taking place at the same time a n d y e t each person i s able, at will , t o sh i ft h is attention t o l isten t o a n y n earby single conversation wh ich " interests" h i m . In the laboratory Cherry found that when h is subj ects were given two speeches (one presented through each side of a set o f headphones), they could attend to e i ther but not both . Some features o f the nonattended speech, however, such as the i ntro duction of non­ human- ori ginated sounds or a switch from a male to a female speaker, were no ticed and reported . By switch ing that m essage to German w i thou t the subj ects' being able to detect the ch ange, C herry demonstrate d that attention to the "un atten d e d " message d i d not exten d to mon i tori n g meanin g . Cherry also made extensive u se o f a tech n iq u e called shadowing, wh ich req uired the subj ect to repeat the atten ded mess age . Such repetiti ons were u s u ally delivered in a monoton e . I t was foun d th at when the subject was involved in generating such verbal responses, memory of the atten ded message was poorer than i n the nonshadowing con d ition . S hadowi n g was most accurate when there was a time lag between hearing and repeatin g the message ( phrase shadowing) . This s u ggested that the message was be in g temporarily stored between stimulu s a n d response, although most o f th is storage seemed to b e temporary . I t i s alm o s t as i f a tape recorder were tem p orarily stori n g s uch verbal message s . The author has used such a very short- term s torage mech an ism when people have talked to h i m wh ile h is " m in d was elsewhere . " When asked if he is paying attention , he is usu ally able to repeat back the last few words of the i r conversation w ithout being aware o f the ir words when they spoke them . At first it was thought that the select i ve atten tion mechan ism was cau sed by

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the b ra in 's blanking out most o f the outp u t of one ear. When both speeches are g iven to both e ars, however, one m essage still is "he ard " and the other atten d e d t o only m in i mally (Norma n , 1976) . Anne Treism an ( 1964) suggested that some sort of partial sensory filters m ust b e mediating between messages stored in this sensory i n formation store , or SIS (as in the " tape recorder p henom enon" j us t d iscussed), and what is now called short-term memory, or STM . An example of STM is rem embering a p hone number you h ave j ust looked up long enough to dial it. Treism a n postulated that the act o f experienci n g a ttention to som eth i n g occurred after SIS storage h a d passed through the filters to the level of STM . She s ugges ted that such filters only a tten uated (weakened) the nonattended ch annels of i n formation, rather th an eliminating them . Because som e m essa ges were atten d ed on the " nonattended" channels (such as hearing your own n am e) , she suggested tha t there m u s t b e sev eral filters, the first of which operates on the gross physical characteristics o f the sounds receive d . Thus, even the m atter of selective attention , wh ich i n turn determines what m a terial is available for learning, may i n volve several s tages . Norman ( 1976) sugges ts that there ex ist h i erarchies o f analyzers i n w h ich the output of the first analyzers of physical characteristics of stimuli b ecom e the input for m eaning analyzers . We pay attent i o n t o a few s e l e ct ed sti m u l i f r o m a w i d e ra n g e o f possi b l e c u es . T h is s e l e c t i v e att e n t i o n m e c h a n is m i s based b o t h o n p h ys i c a l c h a r acte rist i c s o f t h e c u es a n d o n m ea n i n g v a r i a b l es . I t h as b e e n s u g g es t ed t h a t a ser i es o f a n a l yzers a l l o ws u s t o s h ad ow o n e co n v ers ati o n w h i l e i g n o r i n g m o st featu res of ot h e rs ( c o c k t a i l pa rty p ro b l e m ) .

Processing nzodes for a tten ded inp u ts

The typ e of i n i t ial p rocessi n g n1ay be in two basic modes . When looking for the fri en d who is to pick you u p at an a irport, you may th ink you recogn ize h i m or her in the crowd, only to fin d yo urself i n the embarrassi n g position o f greeting a total s tran ger (a false posi­ tive, in sign al detection j argon) . The type of processing u sed when you have a concept or expectancy of what you are look ing for (such as your friend's face) is called conceptual ly driven, or top- down, proc essing ( N orman, 1976) . The sec­ ond mode of paying attention , or i n i tial processing, is called data- driven, or bottom-up , processin g . This involves tun ing your attention to p rogre ssively m ore sophisticated aspects of the stin1uli available in a situation where you are trying to m ake sense of the infom1ation available . In th is n1ode of p rocessi n g , the informa tion passes through your h i erarchy of analyzers, as when you seek to fin d a pattern or form a concept (for exan1 ple, try i n g to understand and re­ member the central i deas fro n1 a lecture abou t a new and complex theory) . In the first mode of processi ng ( top- down ) , you begin processing with "preconcep­ tions" about what you are experiencin g . I n the second mode (bottom - u p ) , you begin with an open mind and try to form organized concepts . These two m odes o f processing m ay (and o ften do) occur simultaneously, as i n the complex task of rea d i n g .

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Most a dults read faster than can be reasonably accounted for by data - d riven p rocessing . Norman ( 1976) s ays this occurs because gramm a tical and o ther con­ textual cues cause langu a ge to be so redundant that you can s kip many ind ivi d ­ ual letters a n d even words w i thout losing m uch m e an in g . Of cou rse, i n tasks like rea d i n g h ighly techn ical m aterial ( data- dense m a terial) or in proofreading, this " s k i mm i n g , " or h igh rel i ance on conceptually driven p rocessin g, may result in your m issi n g i mportant information . That both p rocesses are operating simultaneously may be shown by the p heno menon of reading rapi d ly , suddenly reali z in g tha t y o u d i d not understand a passage, and going back to read it slowly, word by word ( d ata- driven p rocess ­ ing) . N orman s uggests that speed-reading trai n i n g forces a person to place increased reliance on conceptually driven processing, in which most central concepts are recogn ized ( hopefully) and less important m aterial is not attended to . With all this a ttent ional and sensory-s tore-level p rocessing taking place be­ fore you become aware o f perceptions and begin to put them in m emory p roper, i t is hardly surprising that the central nervous system " performs s u bstantial alterat ions o f the physical i mage received by the sense organs" (Norman , 1976 , p . 39) . This conforms n icely to the gestalt theorists' i deas tha t p erceptions are the end result of processing by active organ ism s ra ther than m i rror i mages of envi­ ronm ental stim u l i . In Norman's model , of cou rse, the whole is l ess than the s u m o f i ts p arts, in t h a t only information p assing thro ugh t h e filters i s p erceived or a tten d ed to at the level of consciousness . Norman's theory of d ata-driven rather than conceptually driven atten tional m echan isms has support from some o f the verbal learn in g data . M iller ( 1962) fo und that when words were chunked (combined) into gram matical five-word sentences rather than b e i n g p resented as individual words (which is assumed to requ i re d ata- driven processin g instead of using the concept information avail­ able in grammar) , words in the sentences were correctly recogn ized more times than words presented individually. As " no ise" ( distraction) was increase d , the advantage of having the words in sen tences i ncrease d . Another example o f the interact ion of the two types o f processing can b e seen in Fi gure 11 . 2 . The r a t c a n easily b e recogn ized b ecau se i t conforms to o ur concept p attern o f " ra t . " Presented as p arts o f a puzzle, only fairly well- drawn features are recognized as rat e ars, nose, and so on . Good caricaturists are able to s uggest a well-known pol i t ic i an (of whom you have a s trong concept) with a few p en s trokes which o ften exaggerate dom i n ant facial feature s . This also i ll u s ­ trates the ges talt principle o f Priignanz , which states t h a t w e tend to see and remember things in a way wh ich is closer to their " id eal" form, or gestalt. Recognition o f the whole rat i ll us trates conceptually d ri ven p rocessing; asse m ­ b l i n g a p uzzle illustrates data-driven p rocessing . Because o f the greater s peed of concep tu al ly driven processin g i n readi n g a n d o ther tasks o f this nature, such processing ten ds to b e dom inant a n d inter­ feres w ith data - driven processi n g . Th is is illustrated by the S troop ( 1935) phe­ nomenon, i n which the word " blue" was printed in red ink on a card , the word

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Fig u re 1 1 . 2 A p oorly dra w n ·whole ra t; the s a m e fea tu res with a n d w i th o u t s upporting detail . Th e ra t is recognizable as s u c h , b u t the parts of t h e s a m e ra t may no t be recog nz z ed witho u t eno ugh detail to " c u e off" th e app ropria te p a ttern recog n i tion or concep t of ra t .

"green " i n blue ink on another card, a n d so on . Subj ects asked t o name the color of the ink tend e d to res pon d instead with the word (incorrect) printed on the cards . N o r m a n s u g g ests t h a t i n i t i a l p ro c essi n g of i n f o r m at i on c a n t a k e p l ace i n two m od es . I n c o n c e pt u a l l y d r i v e n , or t o p-d ow n , p r o c essi n g , you beg i n w i t h a c o n c e p t of w h at yo u a re l o o k i n g for ; t h i s p ro c ess i n g i s v ery r a p i d . I n d ata­ d ri v e n , or botto m - u p , p ro cessi n g , y o u t ry to ass e m b l e a c o n c e p t f ro m a m ­ b i g u o u s i n f o r m at i o n . B o t h types m ay o perate s i m u l t a n eo u s l y a n d m ay i n t er­ fere w i t h eac h o t h e r .

The infiu ence of a ro us a l level on a tten tion

Levels of arou sal also affect attention mechan ism s . One of these effects is a shift from conceptually driven p rocessing to data - d riven processing as arousal increase s . This creates the familiar inverted U curve of the relations h i p between performance and arousal, identified as the Yerkes-Dodson law (1 908), shown in Fig ure 11 . 3 . With very low arousal, s u b j ects make q u ick g uesses based on their concepts, and hence make many errors . As arousal increases, subj ects tend to

Q) u c ro

E I.....

0

I.....

Q) Q_

Arou sal

Fig u re 1 1 . 3 a ro usa l .

Th e in verted L I cu rve shows th a t perform a nce zs h ighes t with m o dera te levels of

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focus the ir attention o n d e tails u n til, with very h igh arousal, the cen tral task gets lost in details which m ay be irrelevan t . N orman (1976) suggests this is the reason for pan ic reactions experienced u n d er emergency situation s . Maladaptive n arrow focus in such situ ations can be o vercome by overtraining, which re­ duces the n u mber of cues tha t m u s t b e a ttend e d to by h aving e ach cue trigger a seq uence of responses . Th is effect can be seen in learn in g to drive a car : A t first, each i n d ivi d u al skill (such as shiftin g) req u ires a great deal of attention (data­ driven processin g) u n ti l fin ally most d riving responses become so a u tomated tha t the driver can sing or talk while e a ting and drivi n g . I n a sense , the driving responses have been chu nked i n to fewer an d l arger u n i ts . The effects o f level of arousal on the type of processin g u sed suggests that the capacity of atten tion is lim ite d-bu t th a t th is limitation is b ased on the n u mber of un its a ttend e d to, rather than the amount of informa tion available within each u n i t . L i m i ta tions on a tten tion are of two basic types : the amount of resources available, such as in telligence or effort, and the amount of data avail­ able . Yo u can h ave all the critical principles of learn in g available in one textbook, b u t if you cannot understan d them or if you are unwilling to try to a tten d to the m , you will learn l ittle . Conversely , all the intelligence a n d effort in the world will be wasted if there is l i ttle d ata-as when you try to gu ess an absent person 's true feelings towards you . In general, trying to do too many th i n gs a t once stra ins attentional reso urces an d no th ing rece ives s u ffic ient atten ­ tion to get learned (for exam ple , try i n g to s ki m h ighly tech n ical material) . Gen ­ erally , high-priority tasks ten d to be data l i m i te d ; tasks of low importance (such as trying to stu dy learn i n g principles in the presence of a very a ttractive a n d seductive "friend " ) tend to be resource lim i te d . A s a ro u s a l l ev e l i n c reases , t here i s a s h i ft f r o m c o n c e pt u a l l y d ri v e n p ro cessi n g to d ata-d r i ven p ro cessi n g . A t f i rs t , t h is i s ad a p t i ve , i n terms of fa c i l i t at i n g b e tter l e a rn i n g a n d p e rfo r m a n c e , b u t w i t h v e ry h i g h a ro u s a l t he re i s t o o m u c h a t te n t i o n to d et a i I ( t o o m u c h d a t a) a n d p e rf o r m a n c e d e teri o rates. Perfor­ m a n c e u n d er c o n d i t i o n s o f h i g h m o t i vat i o n t e n d s t o b e l i m i ted by too l i t t l e d at a ; l ow- a ro u s a l tas ks tend t o b e l i m i ted b y t he c o g n i t i v e reso u rces yo u a re wi l l i n g to a pply.

hn n1 edia te tru e ni emory (slz ort- tenn n1 e n1 o ry , o r S TM )

Although y o u m ay atten d to or experience a great many th in gs a t one time in S I S , the n u mber of such th ings that you can remember i mmedi a tely , if asked, is rather s mall . The very act of being asked to tell what one experiences req u ires the act of coding the information wh ich h as p assed the filters of a ttention ; the en d result of such cod i n g is the first stage of real memory, or STM . Norman ( 1 976) reviews the literature wh ich suggests th a t the channel cap acity of short- term , act ive , work­ i n g memory is l i mited to about seven + two u n i ts of information a t any given time (M i ller, 1956) . N o twith s tan d in g th is l i m i ta tion of i m m e diate recollections, we are often aware that "we c an see m ore than we can rem ember . " S ince the seven + two lim i tation of STM is b ased on un its of information rather than on

342

,\ l o if r rn Con tenders

basic yes/no bi ts, * the strategy of chunking several sm all u n i ts i n to a few larger un i ts is a h ighly e fficient way to get m ore inform ation i n to STM in a given tim e . For exam ple, highly practiced typ is ts think and type i n whole words or short phrases rather than in i n d ividu al le tters . The basic tech n iq u e of chu nking is to group several i tems of information i n to a chunk, to name the gro u p , and then to remem ber the name of the group . Th is illustrates the process of coding in infor­ m ation processin g . Coding is a process wh ich can occur i n STM , in long-term mem ory (LTM) , or in the transfer of inform ation b e tween the two types of memory . This brings u s to the q u estion of the differences between STM and LTM . Norman views STM as a low-capaci ty storage u n i t for inpu ts, or as a bu ffer memory system . Since i n p u t levels are always fluctu at in g , STM serves to hold some of the inputs in consciousness d urin g periods of h igh activity , un til fur­ ther processin g can be effecte d . STM is then viewe d as a fragile (a wide variety of i n fluences can d isrupt i t) , active (we are conscious of its contents; any­ thing that d isrupts active bra i n cell functioning obli terates STM) mem ­ ory -trace system that holds a l i m i ted n u mber o f u n i ts of infom1 a tion . This memory- trace system may not only be disrupted by i nterference from new inputs, it also shows decay with time . A n euronal theory of these mechanis m s will b e discussed in the first sec t ion o f Chapter 12 . S h o rt-term m e m ory ( ST M , or i m m ed i ate m e m ory) h o l d s a l i m i ted a m o u n t (seven + two u n i t s of i n for m at i o n ) for a s h ort t i m e f o r f u rt he r p ro c essi n g ( a b u ffer m e m o ry syst e m ) . T h e u n i ts o f i nf o r m at i o n c a n b e very s m a l l ( b i ts) o r l a rge c o n ce p t u a l u n i t s ( c h u n ks) . U n l ess p rotected b y rehea rsa l , S T M is easi l y i n terfered w i t h b y n ew i n p u ts .

Consolida tion -tlze p rocess of tra nsferring infonn a tion fronz S TM to LTM Much of the m a teri al in immed iate , experien tial mem ory (STM) see m s t o vanish witho u t a trace . Over time , however, w e gradually accu mulate infor­ m ation in the nonexperien tial , relatively perm anen t form we call long- term memory, or LTM . Th is inform a tion , which can only be experienced after re­ trieval, is transferred from STM by the process (or processes) labeled consolida­ tion. The prim ary mech anism for consol i d a tion see m s to be rehearsal , as when we try to learn something by repeating i t to ourselves . Sometimes, as in try i n g t o remember a phone num ber j ust long eno ugh t o reach a d is tant phone a n d d ial it, the end res ult is noth ing more than prolonging the STM , and no consol ida­ tion takes place . More comn1 only , we do succee d in consol idating a t least part o f the con ten t o f our STM . Norman ( 1976) s ugges ts tha t t h e s uccess o f rehearsal i n causi n g STM t o translate into LTM p art ially depends upon a second process com i n g i n to play . Th is second process is cod ing. Cod ing can draw upon a s trong

*

" B i t" i s t he term used by com p u ter people t o design a te t h e sma llest possible u n i t of i n form a ­ t i o n t h a t is either a n active state ( 1 ) o r a n i n a c t i ve state (0) . These u n i t s con s t i tu te a b i n a ry ( base 2) n u m ber sys tem . M ore com p lex i n form a t i on i s stored a s com b i n a tion s of b i ts (as w hen the n u m ber 5 is exp ressed i n a base 2 n u m ber system as 1 0 1 ) .

M odern Theories with a Cogn itive E m p h asis

I nput (St i m u l i)

I I I I I I I I I Attention I I f ilters II I I I I I I I

I I I I H igher I o rder I I filters I I I

I I I I

I

I I I I

Cf) Cl> Cf) Cf) Cl> u o "-a.

O> c: ·"'O 0 u c: Cf) 0 - co ·-co .s:::. "'O u :..= :::J 0 Cf) Cf) c: 0

343

Secondary memory

(LTM)

0

Figu re 1 1 . 4 A s u m m a ry sch e m a tic of the s tages of lea rn ing in Norma n 's m odel of h u m a n inform a tion processing . I nforma tion is p rogressively los t in going fro m t h e grea t n u mber of s ti m u li poten tia lly a vailable to th a t being a t ten ded to a t the SIS le vel to the s m a ll n u m ber of u n i ts of informa tion t h a t ca n be h eld in S TM a t a n y given time . Th e capa city of LTM is pre­ su med to be extre m e ly la rge, b u t i ts co n ten t is, of co u rse, slo1oly a cq u ired over time th ro ug h consolida tion of ma terial origin ally stored i n S TM .

preexisting associ ation already i n LTM , and i t is m ore resistan t to i n terference from d is tracting even ts than rehearsal . Therefore, the primary function of re­ hearsal is to hold input inform a tion* in STM ( i m m e d i ate memory) long enough for codi n g p rocesses to b e applie d . The entire process o f learn i n g material (get­ t in g i t in to LTM) in Norman's inform ation -processing theory is s u m m arized in schematic form in Figu re 1 1 . 4 . As we h ave seen , learn i n g seems t o occur m ore q u ickly with conceptu ally driven processing . Th is is p artially a function of the relative contributions of rehearsal and coding in consol id ating STM to LTM and m ay b e experimentally m an ipulated . Res tle ( 1964) fou n d that givi n g s u bj ects tasks and i n s tructions d esigned to elic i t strategy or concept-form ation learn ing resulted in discon t i n u ­ o u s learn i n g o r insightful-type rap i d learn i n g . Tasks a n d instructi ons wh ich focused subj ects' a tten t i on on the i n di v i d u al i tems to be learned resulted in continuou s gradual learn in g . It is assumed that the cod i n g operations in the first case were already present in LTM and the role of rehearsal was m i n i m ized . In the second case, con siderable rehearsal was n ec essary for the s u bj ects to hold the i n formation in STM long eno u gh to invent and perform coding operation s . These results m ay explain why the types o f learn i n g tasks presented t o s u bj ects by behavioristically orien ted researchers typically result in con tinuous learn i n g curves, while the concept- formation tasks o f the cogn i tive theorists are m ore likely to lead to d iscontinuous i nsight learni n g . Both as a gu ide to u n d erstand i n g the concept of consol idation a n d as a n introduction t o the properties of the resulting LTM s , Norman (1976) classifies p rocessin g structu res into two d icho tom ous typ e s : fixed an d flexi b le . F ixed p ro ­ cessing s tructures are innately d etermined a n d consist o f the central n ervous sys tem , the sensory apparatus, the m echan is m s of sensory i n form ation store *

M u ch a s i n form a t i on is held in a com pu ter b u ffer storage system wh ile awai t i n g processin g .

3-l..J.

,\ l o dcrn C o n t e n d e rs

(S IS) , STM , LTM , and rehearsal m echanis m s . These are analogo u s to com puter " h ardware" (compu ters and their in put/ou tput term inals) . The secon d type of p rocessin g structures are flex ible i n that they are d eterm ined by the organ ism's experiences with its en vi ronm en t ; they consist of controlling processes, such as rules and strateg i es (for atten t i on and cod i n g) , an d in tent ional con trol of rehearsal . Flexi ble p rocessin g structures are analogous to the p rograms wh ich s peci fy how the com pu ter hardware will actually process inform ation . W h i l e fixed pro ­ cessi n g s tructures are very s i m ilar for all humans, flexible processing structures are m uch more variable. Most p eople, however, u se som e gen eral pri nci ples of gro u p i n g and categoriz ing of i n form a t i on . For example, the names of the months are u su ally l earned "ch u n ked" into thei r seasons or through the rhyme , " 30 days hath September . . . " Telep hone numbers are learn ed as groups o f d i g i ts rather th an number by number, an d t h e alph abet is learn ed in the form of the rhyme, " ( ab -cd)-(ef- g)-(h i -jk)-(lmno - p) . . . . " As can b e seen i n these ex ­ ampl es, u se o f small n umbers of chunks, which don't stra in the capaci ty of STM , seems un iversal, a n d i n many cases rhythm a n d rhyme cues act as supplemen tal contextu al a i ds (wh ich fac i l i tates conceptu ally driven processi n g) . Tra nsferr i n g i n f o r m a t i o n f ro m S T M t o LT M i s c a l l ed co n so l i d at i o n . a n d i ts p r i m a ry m ec h a n i s m i s rehears a l . Cod i ng S T M i n t er ms o f e x i st i n g asso c i a­ t i o n s i n c reases resist a n c e to i n te rfere n c e . T h i s oc c u rs i n co n c e pt u a l l y d r i v e n p ro c essi n g . C od i n g strate g i es a re f l e x i b l e , l e a r n ed p ro c essi n g p ro c ed u res . s u c h as g ro u p i n g a n d c at e g o r i z i n g i nf o r m a t i o n ( a n a l o g o u s to c o m p u ter p ro g r a m s ) .

Fu rtlzer clz a racteris hcs of LTM

In the v i ew of the g estalt theori sts, perma­ nent mem ory is not fi xed, like words engraved on ston e . Rather, they saw m emories evolvi n g towards better gestalts in accordance w i th gestal t laws . S i nce they saw these laws apply ing equ ally to perception, learn ing, and mem­ ory, their ori enta tion was clearly a prel ude to the information - processi ng theo­ ries, which see the ir processes ( analogous to the ges talt laws) acting at every stage of the learn ing process (wh ich begins w i th atten tion and perception, a n d concl u d es with long- term storage and retrieval mechan isn1 s) . Norn1 an (1976) v i ews processi n g of men1 ori es as not stopp i n g with s torage of the i n format ion i n LTM . Newly arr i ved ma terial, when retri eve d , shows signs o f hav i n g received less processi ng than older memori es . M em ori es tend to get more and more "organ ized . " Norn1an suggests v i ewing th is as a h i erarchy of processing steps leadi n g to increasing " d e pth of p rocessing. " Wi th time, m emories get " hooke d" to more and n1 ore assoc i a t i ons and as a result becon1 e more persisten t and more re trievabl e . H i ghly meanin gful s t i n1 td i (wh ich fi t preexisting LTM structures) are more amenable to conceptually driven processing, lead ing to deep process­ ing in less t i m e . This is offered as an explanation of the tend ency of see m i ngly m ore complex assoc iated informat ion to be learned faster an d reta i n e d longer ( or to be more retri evable) . The possi ble bra in m echan isms of LTM will be d is­ cussed in the next chapter .

M odern Theories with a Cogn itiv e Emph asis

345

LT M is n o t f i xed b u t c o n t i n u es to be p ro c essed by o rg a n i z i n g t h e i n f o r m a t i o n a n d h oo k i n g i t t o m o re a n d m o re asso c i ati o n s . T h i s a c t i v i ty , c a l l e d d e e p p rocessi n g , l e a d s t o l o n g e r reten t i on ( o r easi e r re t ri ev a l ) .

The 1neas u re n1 en t of nzenz o ry a n d t h e p roblen1 of re trieval

A n end uring problem in the stu d y o f wha t is learned i n e ither STM or more perm anent m em ory is how to measure the extent of retention . Ell is (1978) d iscusses fo ur b asic m easurement techniq ues, called recall, rec ognition, savings, a n d reaction time, res pectively . Recall m ay b e the most o bv i o u s techn i q u e . Two types of recall p roced ures exis t : free a n d a id e d . Free recall is simply b e i n g asked to tell wh a t yo u re­ member of somethi n g you h ave j u st experienced (for m easures of STM) or essay q uestions on tests (for m easures of more permanen t m emory, or LTM ) . A i de d recall i n volves remembering som eth ing when you are presented w ith con textu al cu es, such as previo u s words, i n tests of serial learn i n g . S i nce h um a n s ten d to crea te thei r own i n ternal a i ds to memory (s uch as grou p i n g the d i g i ts i n series of n u m bers) , what appears to be free recall m ay actu ally be a i d ed recall . The secon d techn i q u e , recogn i tion, req u i res tha t you correctly i dentify i tems you h ave j u st seen ( i n tes ts of STM) or h ave previously exp erienced (for example, a multiple cho ice exam) . S i nce s trong arousal creates a tendency to 0 recogn ize" th i n gs n ever exp erienced, the general rul e tha t recogn i t i on is more accurate than recall m ay not hold un der cond i ti ons of overly h igh motiva tion (as i n asking a rape victim to i den tify her a ttacker when she is at the p e ak of her anger) . The s avi ngs tec h n i q u e i nvolves asking the p erson to relearn som e th i n g experienced . S avi ngs is a very sensitive m easu re of reten t i on b ecau se a person m ay relearn son1ething m uch m ore q uickly than he or she ori g i nally learned i t , even though h e o r s h e m ay fai l recall a n d recogn i t i on tes ts . Reaction t i m e , fin ally, is a tech n i q u e th at tests recogn i t ion or recall o f well-m emorized i tems; i t en tails measuring the t i m e b e tween s t i m ulus a n d respon se . Th is tech n i q u e perm i ts a d etailed analysis o f m em ory . S tern berg ( 1966) con ducted research on the q u estion of whether s u bj ects exam i n e d i tems i n memory one at a time (serial p rocessing) or i f all i tems were checked simulta ­ neously (parallel proc essing) . H is s u bj ects were gi ven sets of d ig i ts h av i n g one to fi ve n u mbers p er set ; later, they were presented w i th test d i gi ts an d asked to report if the tes t d i g i t was one of the nu mbers in a g i ven set. If the s u bj ects were u si n g p arallel processi n g , then they should h ave been able to check the tes t d i g i t a ga i nst the m e m orized sets o f longer l ists o f d i g i ts i n the same t i m e requ ire d to check them against the shorter sets of d ig i ts . Stern berg fou n d a l i n ear relation­ ship between the numb er of d i g i ts i n the m emorized sets and the time req u i red for the comparison ( ab o u t 38 m ill iseconds were req u ired per d i g i t, i n the m em orized sets) . He i n terpreted these results as showing th at memory scan n i n g took place in the ser i al processing m o d e . Ellis ( 1 978) , however, notes tha t rea d ­ ing, i n experienced read ers, d o e s not proceed i n a letter- by-letter fashion b u t i n volves scan n i n g groups o f words a n d letters i n a p arallel processing fash ion .

346

M odern Con tenders

Th is parallel processing is analogous to the previ ously d iscussed conceptually driven processes tha t are d o m in an t in experienced readers . Therefore, it m ight be concluded tha t serial processing w ould u s u ally be u sed with less familiar material and parallel processing w i th highly fam il i ar m aterial . Up to this point, we have d iscussed the informa tion- processing theory of the stages and processes i nvolved in learn in g . Theorists s uch as N orman have m a d e other contributions to our attempts to understand learn i n g ( including m athematical models that are too complex to review here-consider yourself lucky) . As we saw in the very beginning of this section , however, the gen eral study of learning and m em ory has very anci en t roots, and some of the results o f these anc i ent stu dies have been influential in developing applications for i m ­ proving your capacity to learn a n d memori z e . In a d d i t ion, m o d ern theories may give u s a way to better und erstand why the m em ory-enhancing methods of the ancients work as well as they do . Fo u r t e c h n i q u es h ave been d ev e l o ped to m e as u re t he e x t en t o f reten t i o n of m e m o ri es : ( 1 ) reca l l ( f ree a n d a i d ed by c o n t ext u a l c u es ) , ( 2 ) reco g n i t i o n ( as i n m u l t i p l e c h o i ce tests ) , (3) s av i n gs ( t i m e req u i red t o rel e a rn p rev i o u s l y l e a rn ed b u t a p pa re n t l y forgotten m at e ri a l ) , a n d (4) rea ct i o n t i m e , w h i c h h as been u s ed t o s h o w t h a t l ow-fa m i l i a r i ty m at e ri a l s e e m s t o b e asso c i ated w i t h seri a l p ro­ c ess i n g o f m e m o r i es rat h e r t h a n p a r a l l e l p ro cess i n g ( s i m u l t a n e o u s s ca n n i n g ) . '

The techniques developed by the Greeks and Romans, called mnemonic devices today, illustrate the p aradox that apparently com plex material may b e learned m ore easily than l ists of simple words o r nonsense syllables . Let us now turn to a d iscussion of these techniques .

M nemonic devices, or plans for remembering a n d re trieving

M i ller, G al­ an ter, and Pribram ( 1 960) suggest th at the S-R " b n1 te force" approach to mem­ ory followed by most o f the associa tionists (behavioris ts, or early functionalists) is simply unnatural when applied to hum an (or proba bly h igher organ isms') ways o f remembering things u n d er n a tu ral conditions . They even suggest tha t humans u se plans, or s tra tegies (co d in g sys tems) , i n the s u pposedly rote m em orization of nonsense syllables . When M i ller and colleagues ( 1 960) asked (som e thing not done by most behaviorists) subj ects engaged in a tas k of " rote" mem orization how they had learned the lists, all of the subj ects who learned the lists reported using plans rather than sheer rehearsal . Son1 e put the nonsen se syllables i n to word s ; others used sheer drill b u t w i th rhythn1 ic group ings (as in learn ing the alphabet) or imagined each syllable assoc i a ted w i th a d i fferen t part o f the room or as part o f an image or s tory . M oreover, when s ubj ects were not told they would b e asked to recall the lists, even hun dre ds o f readings o f the lists d i d no t prod uce learn i n g . This showed the critical i m p ortance o f " in tention variables" (resource allocation) . The responses of the subj ects seemed to show clearly tha t memorization was not the automa tic process postulated by the be­ haviorists . It is of interest tha t all the techn iqu es described by the s ubj ects were mentioned in the anc ient text on im proving m emory (Rhetorica ad Here n n iu m ) cited earlier .

Modern Theories with a Cognitive Emph asis

34 7

The art (or science) of developing plans to aid m em ory is called mnemon ics, named after the G reek goddess of memory, M nemosyne . One of the several types of m n em onic d evices d escribed by M i ller and colleagu es (1960) , called the p eg word technique, may be useful for you to learn and u se in memorizing l ists of technical term s . You begin by thoroughly memorizing the following b i ts of doggerel ( the numbers are the places in the l is t and the i tems m entioned are the " p egs") : One is a b u n , Two is a shoe, Three is a tree , Four is a d oor, Five is a h ive, Six are s ticks , Seven is heaven, Eigh t is a gate, N in e is a line, Ten is a hen . The next step is to take the list of term s you w ish to learn and form associ ations ( u su ally i n the form of visual i mages) between your terms and the peg words . As an example of " h anging your list of words to be m e m orized upon the p egs, " consider the followi ng numbered list of word s : (1) a s h tray, (2) firewood, ( 3) p ic tu re , ( 4) c i garette , (5) table, (6) m a tchbook, ( 7) glass, (8) lamp, (9) shoe, a n d ( 1 0 ) phonograph . You m igh t b e g i n b y visualiz ing a b u n o f b read left o n top of an ashtray, t hen setting wet shoes to dry beside a p ile of j ust-igni ted firewood, then a p ic ture s u spended from a tree or a p ho tograph of a tree , and so on . If you carry o u t this exercise completely, you will be surp rised at the ease with \Vh ich the i tems can be learned, in order, and wi th excellen t retention. The role of i m agery i n facilitating learn ing and retention has b een of i nteres t to psychologists for a long time . This u s e o f images a s an associ ative techniqu e h a s b een investigated b y Hasher, Riebman, and Wren (1976) , who com p ared learning of p ic tu res and concrete and a b s trac t nouns u n d er con d i tions of imag­ ery, verbal, and standard free-recall instructions . Im agery was fou n d to h ave facilitated learn ing, and concrete nouns (which could m ore easily be associated w ith i m ages) were learned fas ter than abstract nouns . S u bj ects u si n g i magery, however, d i d not h ave superior long-term retention of their m aterial. In any case, if the use of i magery facilitates learning, then such cond i tions should have an ind irect e ffect on retention, since new m ateri al wh ich is learned m ore poorly would be l ess easy to recall . L e t u s now turn to a second ancient m ethod of a iding learning, the method of loci, which u ses i mages of places or locations in a roo m as a m nemon ic a i d . Although this m e thod is less used tod ay, i t i s o f interest because o f the following s tory about how i t was i nvented . I n ancient G reece, the nobleman Scopas of Thessaly g ave a great banqu et and h ired the poet S im onides of Ceos to chant a lyric p oem i n honor of h is hos t . S i m on id es d elivered the poem b u t incl u d ed a passage i n praise of the twi n gods, Castor and Pollux . E gocentric Scopas was angered and told the poet that he would p ay h im only h alf the agree d - u p on sum and tha t the poet should collect the rest from the twin gods . Just then a m essage arrived for S i m onides telling him to leave the banqu e t h all to see two young m en . The poet left b u t was unable to locate a nyone outsid e . Before he could reenter the hall, the roof collap sed , killing everyone inside and smashing the b od ies b eyond recognition . The poet was able to i dentify all the g u ests for their relatives by v isu alizing the plac e occup ied by e ach a t the table and realized how h is recall of names h ad b een aided by h is m em ory of locations . S p e akers today m ay pay u nknowing homage to S imonides' i nvention of the m e thod of loci by beginning their s peeches w i th the expressi on " in the firs t place . " The firs t place

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in the n1ethod o f loci was, of cou rse , the mental i mage of a specific location i n a b u ilding associated with the open i ng lines of speeches g i ven by ancien t G reek and R om a n orators ( i n Norm a n , 1976) . L in d s ay and Norman ( 1977) have suggested a modern version of the m e thod of loc i . In thei r version, a l is t of words to be remembered (su ch as a shopping list) is associated w i th a set of pl aces lying along a p a th th a t is comm only u sed by the memorizer ( i n the i r example, the p a thway l ea d i n g to the i r u n iversi ty) . The tech n iq u e is to visualize the first i tem to b e m emorized i n front of the door of the s u bj ect's house : i n this example, a loaf of bread so huge i t blocks the doorway. A sim i lar proced u re is followed w i th the o ther i tems on the l ist; the order of the i tems is l inked to the order in wh ich noticeable fea tu res of the pathway would be encou n tered . To recall the l ist, it is only n ecessary to i m a g i n e yourself going from y o u r home t o the fin al p o i n t o n the path , looking at each location along the way and rep ic turing the obj ects placed there . Norman notes tha t the problem w i th these mnemonic sys tems is the i n i ti al effort that m u st be expended to ap ply the m . He g i ves four rules wh ich relate these memory plans to modern theori es of i n formation processing : (1) the mate­ rial m u s t be d ivi ded i n to sm all basic un i ts d ivisible into self-contai n ed sections, consisting of fou r or fi ve u n i ts per section; (2) the secti ons (chunks) sho uld be i nternally organized into logical s tructu res to facili tate conceptu ally driven pro­ cessing, and sections should have n am es ; (3) the mater.ial to be le arned should be related to concepts already p resent (wh ich co uld be peg words) in LTM to faci l i tate cod in g ; (4) the speed w i th wh ich processing depth i ncreases can be i mproved by men tal activi ties such as form ing i n1 ages, fi tting ma terial i nto s tories or mental loca tions, or u si n g rhythm or rhym e as u n i fying devices . The only p roblem wi th th is last tech n i q u e is tha t u su ally the whole rhyme m u st be given to remem ber items comi ng la te i n the lists . All these techni q ues conform to other aspects of inform a t ion- processing theory i n forcing fu ll atten t i on to the releva n t ma teri al, forc i ng chunking, and provi d i ng structure to relate the chunks to one another and to previou sly learned materi al . S i nce n1en1 ori es so organ i zed h ave rece ived extensive processi n g , they are usually easily accessi ble from LTM . This bri ngs up the fin al p o i n t, tha t n1 os t inform a ti on - process i ng theorists ass u n1 e that true forge tti ng ( pern1 a nent loss of inforn1 a tion) is a phe­ non1enon associated only wi th STM . I n abi l i ty to ren1 em ber n1 ateri al that has reached LTM is ass u n1ed to re flec t i n adequ ate processing and is a fa ilure of re trieva l . Thus, the success of psychoanalysis i n getting a patient back i n touch w i th lon g - i naccessi ble n1 e1n ories is seen as ca u sed by the fact th at the sessions provide a d d i tional processing thro u gh free associ a t i on . S u bj e cts u si n g d e l i berate p l a n s or st rateg i es t o a i d t he m i n m e m o r i z i n g m ate­ r i a l h ave been fo u n d to l ea r n faster and reta i n m o re . P l a n s d e r i ved f r o m a n c i en t t ec h n i q u es for a i d i n g m e m o ry are ca l l ed m n e m o n i c d ev i c es ; t he t w o rev i ewed h e r e ( pe g wo rd te c h n i q u e a n d m et h od of l o c i ) u s e t he fo r m a t i o n o f i m ages as a n a i d i n l ea rn i n g . I m ag ery t e c h n i q u es h ave b e e n fo u n d to a i d l e a rn i n g b u t not reten t i o n .

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Persp e ctiv e The stage s of m em ory reviewed here a re widely, b u t not u n i versally, accepte d . Some theorists p ostulate fewer or greater numb ers o f m em ories, and som e even see S I S as simply the con d ition of fastest trace decay and LTM as the con d ition o f slowest trace d ecay. Norm an o ffers the fol lowi n g introspective exercise in d e ­ fense o f h is theory : Although it i s e a s y t o recall i m me d i ately the l a s t few words s a i d by a conversation p artn er ( an d for some of us, even easi er to parrot back those words) , l asting verbatim recall requ ires considerable rehearsal of the m ate­ rial while i t is s till i n STM . In a sen se , the inform ation- processing approach represents a step b ackward for p sychology . At the turn of the century , both J ames and Ti tchener d iscussed attention al m echanisms and types of m em ory correspon d in g to STM a n d LTM that they d iscovered through their " m en t alistic " i n trospection metho d . Skinner ( 1974) dism isses i n formation -processi n g t heories as more o f the s ame vague s peculation about u nobservable inner processes originally repu d i a ted by the behaviorist revolu ti on in psycholo gy . Chapter Perspective

The fo ur approaches presented in t h is chapter d i ffer almost as much from each other as they do from connection i s t approac hes . The type of appro ach rep­ resen ted by S altz's theory is d erived from the s ame experimentally ori ented learn ing theory mainstream as the connectionist approaches, wh ile the other three approaches all are d erived from other tra d i t i ons . Although information­ processin g theory is also closely t i ed to experi mental psycholo gy , its heavy u se o f computer term s and theory m akes i t a more eso teric b ranch o f psychol ogy . The other two a pproache s are not even deri ved from psychology a s an aca­ d e m ic d isci p li n e . Cho msky' s theory has i ts roots in p h i l osophy and l i n ­ g uistics; Pi a get's theory ori ginated in b i ology a n d today is m ore closely i d enti­ fied with developmental a n d e d ucational psychology than with experimental psychology. This diversity is reflected in the ways in wh ich the data u se d i n these theori es h as b een collected . While the neofu ncti onal ist an d verbal learn i n g theorists s uch a s S altz an d the i n form ation- processing theorists h ave con d ucte d m uch o f their experimental work w i th college s tu d ents, Piaget almost exc l u ­ sively and S altz t o some extent have worked with sm all ch ildren . C homsky's theory ori gin ated m uch m ore from h is logical analysis of language than from experim en tal work per se , and Piaget has rel i e d extensi vely on ob servational d ata rather than the results o f controlled experiments . These theories are conse­ q u en tly foc u sed on d i fferent learn in g phenom en a than the theori es tied to the learn i n g psychology mainstream and are thus somewhat d i fficult to integrate with m a i n stream theori es . Such an in tegration , if possi ble, would be desira b le if the comprehen sive learn in g theory of the future is ever to be d eveloped . H opefully, the d i versi ty o f m o d ern cogn itive approaches reviewed in this chap­ ter will prove complemen tary to the ways in which the connec t i on is t trad i tion is evolvi n g .

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tvl odenz Con tenders

Key Terms accommodation

deep structure

p hysical knowledge

assimilation

d i me nsion

positive i nstance

attrib ute

disj unctive concept

preoperational

b ase rul e

egocentricity

p rob abilistic concep t

bit

equilibration

p roj ection rul e

b oundedness

formal operations

b uffer memory system

function

channel capacity

generative grammar

chunk

i ntegration

classification skill

kernel sentence

coding

linguistic compete nce

common response mo del

logico-ma thema ti cal knowledge

cocktai l party problem concept attainment

recognition savings schemata selective attention serial processi ng seven

+

two

shadowing

media tional facilitation

s h ort-term memory (STM)

method o f loci

concrete operations

mnemonic device

conj u nctive concept

natural language

consolidation

recal l

long-term memory (LTM)

concep tually driven (top-down) p rocessing

conservation

reaction time

overtraining

simpl e concept social-arb i trary knowl­ edge S troop phen omenon structuralist

p arallel processing

su rface stru cture sente nce

data-driven (b ottom-up) processing

p articular grammar

transformation

partist strategy

trans form ational ru l e

decentration

peg word tech nique

u niversal gram mar

deep processing

ph onological rule

w holist strategy

Annotated B ibl iography

A good introduction to the area of verbal learn ing and cogn ition in general is provi ded in E. Saltz, Th e cog n i tive b a ses of h u m a n l e a rn i ng ( H omewood , Ill . : Dorsey Press, 1971) . A classic text i n the area is J . S . Bru n er, J . J . G oodnow, an d G . A . Austi n , A s t u dy of th i n king (New York : John Wiley & Sons, 1956) . A much more recen t text that provi des a good overvi ew o f issues and research in cogn i­ tive learn in g theory is H . C. Ellis, F u n da m e n t a ls of h u m a n l e a rn i ng , m e m o ry , a n d cog n i tion , 2 n d e d . ( Dubuque, Iowa: Will iam C . Brown , 1978) . Cho msky's theory o f psychol i n gu is tics a n d h is cri tiques o f Skinner's theory o f language learn ing are given in N . Chom sky, L a ng u age a n d m i n d , enl . ed . (San

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Francisco, C a . : H arcourt Brace J ovanovic h , 1972) . A less i d i osyncratic and m ore recen t overv i ew of psychol i n gu istics is D . S . Palermo , Psychology of language ( Glen view, Ill . : Scott, Foresman , 1978) . A n easy- to-read introduction to Piaget is h is " How ch ildren form mathe­ m atical concep ts" (Scientific A merican , 1953 , 189, 74-79) ; a m ore recent and com­ prehensive work is h is Science of education and the psychology of the ch ild (N ew York : Vik ing Press, 1 970) . A n informative collection of papers, including d iscus­ sions of Piaget's theory o f m oral d evelopment, m ay be fou n d in V. P. Varma and P. Williams ( E ds . ) , Piaget, psychology and education (I tasca, Ill . : F. E. Peacock , 1976) . U seful suggestion s for apply i n g Piagetian principles t o the classroom are given in B . J . Wadswort h , Piaget for the classroom teacher ( N ew York : Longman , 1978) . A very readable and comprehensive i n troduction to the area o f inform a tion- processing theory i s presented in D . A . Norma n , Me mory and atten­ tion : An introduction to human information processing (New York : John Wiley & S ons, 1976) .

T h e B i o l o g i c a l B o u n d a r i e s o f Le a r n i n g

I n the previo u s chapters on cogn itive approaches to learn ing theory, we re­ vi ewed theorists (Montessori, Chomsky, Piage t, a n d others) who were not part of the mainstream of academ ic learn ing theory psychology . I n this chapter, we will cover the contributions and ideas of theorists ident ified with com parative psychology, neuropsychology, an d behavioral bi ology whose work adds an­ other important d imension to our understan d i n g of the learn i ng process or processes . By relating learn ing p henom ena to biolo gical principles, such theorists h ave enriched our u n d erstan din g in many ways . As we have seen , two dominant trends seem to be emerging in o u r concep­ tu alization o f the learn ing process : (1) an increasing tendency to explain even such "sim ple" forms of learn in g as con d itionin g in terms of cogn itive vari ables (awarene ss, p redictive value of cues ) , an d (2 ) an increased atten tion to biological variables . We shall explore the la tter trend in this chapter . The biological vari­ ables we will examine are of two types : (1) those rela ted to the neurophysiology and neuroanatomy of learn ing, and (2) those related to inn ate and "sem iinnate" variables wh ich re flect evol utionary pressures on the selection of adaptive modes of beh avi or . Historically, m o s t learn i n g theories h ave been concern ed with the effects of environmental cues on overt behavior. Th is position has taken its n1 ost ex treme form in the rad ical behaviorist approach (now represented by the orthodox Skinnerians) , which has deliberately tri ed to avoid specu lations about even ts occu rring within the "black box" of the brain . Even the cogni tive behavioris ts and the cogn itive theoris ts h ave , for the n1 ost part, confin ed their speculations about intern al processes to discu ssing in ternal variables in tern1 s of " i n terven­ ing variables" (hypothe tical processes not rela ted to neurophysiological or evo­ lu tionary data) . Entit ies such as schen1 a ta, concepts, buffer n1 emories, and S -R bonds, as well as processes s uch as bonding, eq u il i bra tion, acco mmodation, and se nsory filtering, are in heren tly unobserva ble. In part, this approach by learni ng theorists represents a residual react i on against the na ive instinct theo­ ries and n1 en talis ms of psychology's early h is tory . I n part, i t may also reflect the repud iation of the pri n1 i t ive neurological n1 odels o f learnin g deve loped by Pav­ lov and the gestalt theorists . Finally, it n1 ay reflect the woe fully in adeq u ate background in biological principles most American learn i n g theoris ts possess . Whatever the reasons, the selective effects of evol u tion in preparing organisms to assoc iate some cues n1 ore easily than o thers h ave largely been ignored . Both the " black box" (Skinnerian) a n d in terven i n g variable approaches to u n d er-

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stan d in g learn i n g tell u s li ttle about the neurophysiology of learn ing . Almost every theorist revi ewed i n this tex t , however, would agree that learn in g is ultim ately a function of the activities of the b ra i n an d i ts constitu en t neuron s . B efore World War II, the techn i q u e s for investigating the functions o f the brain were relatively prim itive . M ost research on the relation s h i p o f the bra i n to behavi or was con ducted by cutting out sections of bra i n (ablation) or damaging them (lesion ) . A host o f m ore advanced m ethod s have b een develo ped since then , i nclu d i n g electrical stim ulation of, and recordi n g fro m , selected brain areas ; c hem ical stimulations ; and m uch m ore precise lesion tech n iques (s tereotaxic s urgery) . Th is entire l i n e of research has greatly i ncreased our knowledge of bra i n function in g an d i ts relation s h i p to learni n g . We will see how neuropsychological technology h as advanced by comparing the p ioneering con ­ tri butions of Lashley an d Hebb to the m ore recent com prehen sive neurological model of learn in g an d m emory developed by Pribram . Pri bram's theory will be explored in the m o s t detail becau se i t i ntegrates m an y l i n es of physiologically oriented research on learn i n g an d m em ory, an d because Pribram attemp ts to relate the processes postu lated by Norm an ( in h is i n formation - processin g theory) t o neurolo gical data an d theory . While the develo ping s c i ence of neuropsychology ( a typ e of p h ysiolog ical psychology) h as increased our u n d erstan d in g of what happens within the " black box" o f the bra i n , advances in d elineating the effects of evolutionary vari ables h ave come from two d i fferen t scien tific d iscipli n es . One of these is the branch of behav i oral b iolo gy known as eth ol o gy, w h ich originated in Europe through the work of K onrad Lorenz, N iko Tin bergen, an d others . The p u b l ica­ tion of Lorenz's b ook, On Aggression ( 1963) , created considerable fomen t among en vironm entally b i ased American soci al scientis ts an d rekin dled the debate over i n stinct versu s learn i n g (nature/nu rture) . Ethology is characterized by a s tron g reliance on naturalistic observation i n the field and by use of experim en tal procedures d esigned to approximate n atural con d i tions in field an d laboratory . An exam ple of such an experim en t would b e to present various models of eggs outside the nest of a herri n g gull in order to d eterm i n e wh ic h stim ulus features of the mo dels are most effective in eliciting the gull's instinctu al response of e gg retrieval . The ethologists suggested that m an y seem i n gly i rra tional h u m an b e ­ h av iors (such a s war) reflect the s a m e i n s tinctual m echan isms (such as territory defen se) m e diating aggressi on in m any lower an i m als . This v i ew of h um an m otivation as having instinctu al componen ts h as recently b een exten d ed in the n ew (and very con troversial) science of soc iobiol ogy, w hich will be briefly re­ v i ewed after we d iscuss the instinct theory of the etholog ists . Another con tribu­ t i on o f the ethologists has b een the d iscovery of the p henom enon of imprinting, or the rap i d learn ing of a very s tron g attachment to m e mbers of one's own s pecies during a sen sitive p eriod of early d evelopm en t . This relatively (or some­ ti mes totally) i rreversi ble type of learn i n g h as characteristics of both learn i n g an d i n s tinct. The o ther scien t i fic d isci pline w h ich h as contribu ted to our u n d erstan d i n g o f the e ffects of evolution on learn in g i s the b ranch of American psychology known as comp arative psychology. Although comparati ve psychology began

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very early in the h istory of psychology (in a sense , any psychologist who studies the behavior of more than one organ ism is a com parative psychologist) , onl y recen tly has i t focu sed on inn ate variables in behavior . Comparative psychology can be distinguished from etholo gy in the followin g ways : I t tends to focus m ore on learn ing variables ( rather than lo oki n g for examples of instinctual behaviors) , and com parative psychologists make extensive use o f laboratory experimen ta­ tion on a relatively restricte d number of species . Wi thin t h is tradition , we will review the work of: (1) the B relan ds, who d iscovere d that learn ed behavi ors similar to instinctual behaviors ten d e d to " d ri ft" towards b ecom i n g like the instinctual behaviors, (2) Bolles, who postulates that the behavior shown by an imals d urin g avoidance learn in g reflects "species-specific defen se reaction s, " and (3) G arcia, Seligman , and o thers, who h ave found that organ ism s can easily associate some types of cues but may have great d i fficulty in associating other types . G arcia has related his results to inn ate " ba i t-shyness" mechan is m s and suggests that all learn ing can be classi fied accordi n g to how inn ately prepared the organism is to learn a particular class of relationsh ips . Seligman suggests that in stinct and learn ing of such responses as bar-pressing by ra ts are only points on a preparedness continuum , w i th phenomen a such as imprinting and learn i n g of bait avoidance fallin g somewhere b e tween ins tinct an d unprepared learn i n g , and con traprepare d learn ing at the opposite en d from instinct. All of these con tributions suggest that it is necessary to take ,i n to account the evol u­ tionary h istory of each organ ism studied . Thus, the principle of equip oten tial­ ity , wh ich underlies the " laws of learn ing" d escribed by most connection is t theoris ts, may only a pply to "unprepared" responses, such as bar- pressing by rats . As e vidence for the influence of genetic variables on learn in g, the chap ter concludes with data concern ing the d i fferen tial learn in g abilities o f s trains of ra ts bred to be ei ther "m aze bright" or "m aze dull . " As you read this m a terial, you should try to learn : (1) where in the b ra i n learn ing and storage o f the d i ffere nt types o f n1em ory occur, ( 2 ) the probable physiology of the d i fferen t types of memory first presented in the section of C hap ter 1 1 covering the information - p rocessin g approach to learn ing, (3) how Pribram 's holographic model of learn ing reconciles many d ifferen t approaches to the neuro psychology of learn ing, ( 4) how d i fferen t "learn ing" phenomena show how learn ing is related to ins tinct an d the e ffects of e volution , and (5) what types of behavioral phenom ena bes t illu s trate b i ological i n fluences on learn ing laws (such as imprinting, tas te aversion , species- specific defense reac­ tions, and so on) . The N eu ropsych ology o f Learn ing and Memory

A B rief His tory of Ne u rop lr ysiolog ical App ro a clres to Learn ing a n d M e111 ory Tire sea rclr for tile en g ran1 Investigations of the relationship of the brain to learni ng and memory have been of two main types : (1) a ttem p ts to relate brain anatomy to the process of learn i n g and to the storage sites of long- term m e n1 ories (engrams) , and (2) attem pts to deline ate the physiological processes

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involved in learn i n g and retrieval of memories . We shall first review the ana­ tom ical approach . Historically, there h ave been two d i am e trically opposed views about the extent to which learn i n g and memory can be related to s peci fic brain areas . The extreme localizer ( m o sa ic) view m a in tained tha t s p ecific m em ories are s tored in specific location s m uch as m a il is s tored in p i ge onholes in a post o ffice (in G ardner, 1 97 4) . This posi tion was d erived from the early successes of the great n euroanatom ists, such as Paul Broca, in localizing cortical function s . A less extre m e version of this view was advanced by Pavlov , who suggested that the cortical proj ection area s associated w i th U S s act as dominant foc i ; when exci te d , they rad i a te electrical exc i tation which acts t o attract the excitation produced by a CS, so that eventually t he CS has the power to elic i t the reflex. Thus, Pavlov saw cla ssical con d i ti on i n g as i nvolving electrical connecti on s between localized cortical proj ection areas (in Schneider an d Tars his, 1975 ) . Opposed t o this localizer v i ew was t he t heory, advanced by the gestalt theorists, that the b ra i n functions a s a whole through electrical field forces generate d b y the brain durin g learni n g . K arl L ashley, an American p hysiological p sychologist, s p e n t over 30 years tryin g to determine where, if anyplace , the engram m i gh t be localized. In his early work, he i mplanted insulating s trips of m ica b e tween reg i ons of the cortex to d isrupt any p ossible field forces without effecting any losses o f m e mory or learn i n g . He m a d e deep cuts b e tween cortical regions to d isru p t the kinds of connection s between U S - excited proj ection areas an d CS-excited proj ection areas p o s tulated by Pavlov-again, wi thou t losses of m em ory or learn i n g abil­ ity. H e then systematically removed various cortical regions fro m thousands of rats w i thout d e s troyi n g their abil i ty to learn an d remember , thereby d isprovin g the localizer hypothesis . Reviewin g his research, Lashley concluded : " I some ti m es feel, in reviewi n g the evi dence o n the localization of the memory trace, that the n ecessary conclu­ sion is that learn i n g j ust is not p o ssible at all . Nevertheless, in s p i te of such evi dence agains t it, learn in g does sometimes occur" (Lashley, 1950, p. 501) . While Lashley fou n d no evi dence of localization of m em ory, m e mory d efic i ts d i d appear i n som e of h is subj ects . The extent of such deficits, however, was related to the extent of the lesions-not to their location . From th is data, L a shley (1963) advanced h is theory of mass action, wh ich s ta ted that with in function al region s (such as the visual association cortex) , all parts of the regi on were equally effective in carry i n g out the funct ion normally served by the entire cortical region . This mass function (wi th i n regions) comprom ise between s trict locali zation theories and s trict holistic theories h as received clin ical support. Observing bra i n - d am aged World War I veterans, Kurt G oldste i n ( 1963) noted that patients w i th damage in the associ ation (th inking?) areas adj usted by ac­ ceptin g tha t the ir o verall i n tellectual abilities had been reduced . Luria , the R ussi an cogn i tive-neuropsychologist whose work was discussed in C hapter 8 , h a s also supported the m ass function (mass action) concept by develo p i n g a series of testing s trategies to evaluate the amount of intact function rem a i n i n g

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w i th i n a damaged region ( L u ria and Majo vski , 1977) . If some i n tact fu nction rem a ins, the patient can be tra i ned to compensa te for beh avioral deficits (show­ ing plas tic i ty , or flexi b i l i ty, in brain functioning) . Test i n g b o t h t he h o l i s t ic a n d the l o c a l i z e r v i ews of b ra i n f u n c t i o n i n g a n d m e m o ry , L as h l ey f o u n d m e m o r i es to b e rep resen ted d i ff u s e l y t h ro u g h o u t v a r i o u s re g i o n s o f t he cere b ra l c o rt e x .

Following h is stu d i es of the effects of cortical lesions, Lashl ey rej ected Pav­ lov's hypothesis th at U S -exci ted areas and CS-excited areas com m u n icated thro ugh transcortical (horizontal) connecti on s . He l eft open, however, the pos­ sibi lities that e ither classical conditioning could be learned by s u bcortical cen­ ters or th at cortical regions com m u n icated i n d i rectly thro u gh vertical connec­ tions to s ubcortical relay centers . Support for the first hypothesis was prov i d ed by Lashley h im self when he fou n d that rats could learn a l ight- dark discri m i n a ­ tion after ablation of the i r v i s u a l cortex . Th is removal o f t h e visual cortex , how­ ever, res ulted in an alm ost com plete loss of previ ou sly l earned d iscrim i n at ions, s u ggesting that the con d i tioni n g was norm ally l earned an d stored at the cortical level . Further, th is s uggests th at subcortical visual structures ( the optic tectum) h ave the capacity to learn and store h ab i ts but do not do so as long as the visual cortex is i ntact. These res ults have been supported by the work of Doty (1961) , who fo u n d horizontal cuts i n the cortex o f cats to h ave no effect, b u t vertical cuts (wh ich in terfere with subcortical connecti ons) to impair, b u t not eliminate, classical con d i tion i n g . Wh ile teac h i n g at Occ i d ental College , the author and two of h is stu dents conducted a series of experiments wh ich n1 ay also be i n terpreted as su pporting the idea that learn ing is possible at e i ther cort ical or s u bcortical sites. They applied bi ts of pa per soaked in potassi u m chlori d e (KCl) solution to the exposed men1 branes (the d u ra n1a ter) of both cortical hen1 is p heres of the ir experi mental rats, and they applied saline solution to the exposed n1 em branes of the " whol e b ra i n " control rats . (This procedure is sup posed temp orarily to s h u t off fu nctioning of the KCl- trea ted cort ices, or t o create a " reversi ble lesion . " ) Both gro u p s of rats were able to learn a bl ack-wh ite d iscrin1 i n ation i n the first experiment (Swenson and Goldwi tz, 1972) , with exper i n1 en tal a n i n1als learn i n g almost as fas t as saline-control rats . In the second experin1 ent, the ra ts were req u i red to ru n , alternately , into a white ch an1 b er and i n to a black ch am ber in successive tri als . Before the beginning of each tri al, a l i gh t was turned on over the entrance to the correct chan1ber. Both groups of rats learned th is si mple "concept" of alternating fron1 cham ber to chamber, altho ugh the KCl gro u p (also called the cortical spread ing depressi on, or CS D, gro u p because KCl causes waves of depression of cortical function i n g) took n1ore trials to reach 90 p ercent accu racy (Swenson and Catan i a, 1973) . When the statu s of the an im als was reversed during tes t i ng o f re ten tion (the whole- b ra in con trol ra ts were tested after application of KCl and the exper i n1 ental a n i m als were tested witho u t KCl), both gro u p s showed retenti onal deficits. This s uggests that the KCl rats learned through s u bcort ical n1 ech anisms a n d the whole-bra in rats learned through cor­ tical n1ech anism s . When the i r tes ting statu s was reverse d, both gro ups showed

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effects that could be i nterpreted as resulting from interference between the two learn i n g system s . I n a further test, the g u i d e l i gh ts were turn e d off and all an i m als were tested i n the ir orig i n al tra i n in g state (depressed or whole b ra i n) . U n d er these cond it ions, the KCl rats showe d marke d decl i ne s i n accuracy, wh ile the whole- bra i n controls were u naffected by the change . Th is fin al res ult (Swenson and Catania, 1 974) suggests that the subcortical learn i n g centers o f the KCl rats learne d primarily through the cues p rovi d e d by the g u i de lights, whi le the rats w ith intact cortices learned a m ore flexible concept . It is, of course, not surprising, if one reviews the li terature on classical cond i tioning of lower ani­ mals, to fin d that ves t i g i al su bcortical cen ters can be classically con d itione d . M any a n imals w i th no cortex at all (and some w i thout anythi n g w e would call a brain) can be classically con d i ti oned (reviewed i n Schneider and Tarsh is, 1 975) . I f we conclude that learni n g is normally som eth in g that takes place at the cortical level in mammals, can we say anyth i n g further abou t local ization of memories?* D i amond and Neff ( 1 957) foun d th at cats s howed a loss of reten ti on of an a u d i tory d iscr i m i nation after rem oval o f thei r audi tory cortex but were able to relearn the d iscri m ination . T h is suggests that mo dal i ty-specific learn i n g (as a u d i tory alone) i s usually s tored only in the appropriate region o f the cortex, but that som e o ther b ra i n regions can store such i n form ati on . Are there , then , any areas of the cortex that are p articularly i m p ortant for memory s torage and learning? Penfield (1969) was able to evoke complex mem ories in the temp oral lobes of patien ts await i n g surgical treatment for ep ilepsy. The complexi ty of the mem ory was p roportional to the i nten s i ty of the electrical stimulation appl ied . S p i nelli and Pribram ( 1 966) fou n d tha t stimulating the temporal lobes of mon­ keys through permanently connected electrodes (at low in tensi ty) o ver a period of weeks resulted i n fas ter learn i n g o f visual d iscri m ination problem s . Monkeys w i th temporal lobe lesions are not able to learn "learn i n g sets , " or general s trate gies for problem solvin g (Ri opelle an d A des, 1 951) . This suggests that the temporal lobes h ave a spec i al role in complex learni n g an d memory . Penfield's results, however, could also be i nterpreted as show i n g that the temporal lobes are especi ally i mportant for retrieval of memories rather t h an for their storage . The focu s on the temporal lobes is i nteresting because these lobes h ave embedded w i t h i n them ( below the temporal cortex) s tructures that are known to h ave an importan t role in the trans fer of short-term mem ory to long-term mem­ ory (consol i d ation) . Each tem poral cortex h as extensi ve connections w i th such a s tructure , known as the hippocampus. When the h ippocampus is d amaged i n h u m ans, they show severe anterograde amnesias ( in a b i l i ty to form new perm a­ nent m e m ories) , although exis t i n g long-term m e m ories rem a i n i n tact . Such a person is forced to l i ve i n a world i n wh ich i t is always a few hours or m in u tes after the acci d en t that cau sed the i nj u ry (M i lner, 1 966) . (We will further review the functions o f the h ippocam pus i n o u r d iscu ssion of Pribram's theory . ) I f the tem p oral cortex and the u nderlying h i p pocam pu s are espec i ally i m plicated i n learni n g a n d memory, is there any p art o f the cortex which may not store *

You m ay fin d it helpful at t h is poi n t to tu m ahead to Figure bra i n show i n g areas i n volved in m em ory .

12.3,

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m em ories? The answer seems to be the fron tal cortices, which, w h ile they m ay be i n volved i n reducing dis tractib i l i ty duri n g learni n g , seem to h ave no s torage function s . Tens o f tho usands of human patien ts have been subj ected to removal of parts of the frontal lob es (and, in earli er days, to rem oval of the entire an terior portion) , w i th few, i f any, reports of m em ory loss (reviewed i n Brown , 1976) . These areas seem i n volved in abstract th in king rather than m em ory . There is one more q uestion we m u st try to answer before m ovin g on with the h i story of the processes o f learn i n g . D o m emories b ecom e localized i n j ust one of our cerebral hem ispheres, or does each hem isp here con ta i n "carbon copies" o f the m e m ories o f the other? In a series of an i m al stud ies, Sperry ( 1961) has s hown that normally the engram formed by one surgically isolated hem i ­ sphere i s transferred across the fi ber b un dles (corp u s callosum an d o thers) con ­ necting the two hem ispheres . Moreover, when these fiber b u n dles are cut i n h umans ( for relief o f the symptom s of m ajor ep ilep sy) , the person c a n b e treated in such a way that independen t m em ori es are learned by each hem isphere ( G azzan iga, 1967) . It has also been found (for right- h an d e d persons, at least) that the left hem isphere is specialized for verb al fu nctioning and the right hem i ­ sphere for spatial manipulation a n d recogn i t i on o f tem p oral seq u ences, such a s melo d i es . This m ay suggest that verbal a n d spatial memories d o n o t com pletely transfer o ver to the right and left hem ispheres, respecti vely, in a dult human s . G azzan iga (1967) h as reported tha t when a spl i t- b ra i n subj ec t (whose i n ­ terhemispheric connections h a d b een surg ically severed) was s hown a p ictu re o f a n u d e , proj ected so tha t i t was only receive d b y her r i gh t hem isphere, she d en i e d seeing anyth ing, but right- b ra i n reco gn i ti on was evi d enced by her sly s m i l e . This demons trated that verbal labels were stored exclusi vely in her " blind " left hemisphere . I n s u m m a r i z i n g t h e atte m pts to f i n d a n a n ato m i c a l l o c at i on f o r t he e n g ra m , w e c a n m a ke t h e fo l l ow i n g po i n t s : ( 1 ) M e m o ry i n t h e i n t a ct m a m m a l i s sto red t h ro u g h o u t b road reg i o n s o f t he c e re b ra l c o rt e x e x c e pt i n t h e f ro n ta l l o bes ; ( 2 ) m e m o r i es t h at a re s p e c i f i c to o n e sen sory m o d a l ity a re u s u a l l y sto red i n t h at sen sory recei v i n g a re a , b u t o t h e r m e m o ry a reas c a n store t h is t y p e of i n f o r m at i o n : (3) t he t e m p o ra l l o b es a re e s p e c i a l l y i m p o r t a n t f o r e i t h e r the s t o r a g e o f co m p l e x m e m o r i es or t he i r re t ri ev a l ; (4) t he h i p p o c a m p u s, w h i c h l i es i n t h e m ed u l l a o r w h i te m atter o f t h e t e m p o r a l l o bes. i s i m p o rt a n t i n t ra n sferri n g c o m p l e x s ho rt-t e r m m e m o r i es to l o n g -t e r m m e m o r i es , a n d ( 5 ) m e m o r i es " l a i d d o wn " i n o n e cere b ra l h e m i s p h e re t r a n sfer to t h e o t h e r he m i ­ s p here ; s u c h t ra n sfer, however, m ay be weak i n t he case o f ve r b a l i n f o r m a t i o n ( w h i c h is stored i n t he l eft h e m i s p here o f m o s t p eo p l e) a nd s o m e t y p es o f s p at i a l -te m p o r a l seq u e nces ( w h i c h a re m o re st ron g l y rep resented i n t h e r i g h t he m i s p h ere o f m o st peo p l e) .

I t is clear that the strict localization theory o f memory is i nvali d , although m em ories are not to tally d i ffu se . Ra ther, they are somehow represen ted througho u t l arge regions o f the cortex . This su ggests that in divid ual memories m ust not be coded on ind ividual neurons (cell bod ies of n erves) but must instead be coded in pa tterns of cell s . S ince neu rons form patterns by their

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Axon endf eet CELL 2 O R I G I N ATI N G C EL L

(CE L L 1 )

D endri tes

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Fig u re 1 2 . 1 Wh en the firs t cell is excited, i t sends a m essage o u t its axo n wh ich synapses with the den dri tes of Cell 2 . Cell 2 th en sen ds a m essage o u t i ts axon to Cell 3 (th e message m us t cross th e synap tic cleft between them ) a nd Cell 3 reexci tes Cell 1 . This co mple tes the firs t circ u it of th e loop . Cell 2 is then reexcited by Cell 1 , a nd so on . Th e long a rrows show the direction of the m essag e .

con n ections to o ther n eurons at the ir syn apses (the gap s b e tween the output of one neuron and the input areas of o ther neurons) , alterations in synaptic struc ­ ture o r function h ave becom e the prim e targets i n the continuing search for the structural basis of long- term m e m ory . We will now exam ine synaptic even ts and the processes o f m em ory .

The p rocesses of learn ing a n d memory

Don ald Oldin g H eb b has b een ac­ tive i n the investigation of b rain functi ons and memory since the m i d dle 1930s . He was one of the first p h ysiological psycholog ists to d evelop a comprehen sive m ultistage theory of learning, a theory which h as influenced m any cognitive and neurological theorie s of m em ory . The stages of m em ory d e scribed in the preced in g chapter in the d iscussion of D onald N orm an's information- processing theory of learning are very close to the s tages described by Hebb . I n turn , Karl Pribram's theory, to be described n ext, further d evelops m any of the i d eas advanced by H eb b . Hebb first d istingu ishes b e tween imme diate memory (short-term memory, or STM) and long-term mem ory ( LTM) . H e suggests that STM consists o f active networks of n erve cells that repeatedly exci te one another . These reverb erating loops of cells can m a intain a stim ulus trace in the brain from a few seconds to many m in u tes . What m akes the p atterns of cells form into loops is that the cell which origin ally brings the sensory inform ation into the cortex is hypothesized to rece ive onto its receiving p rocesses (dendrites) i n pu ts from cells further along i n the loop . As the output p rocesses (axons) of these cells stimulate the first cell, it then sends signals back to the n ext cells, which ultimately causes the first cell to b e restimulate d . The excitation i n the loop , i f fairly weak, fin ally d ies down ; the loop then " breaks" and the information is los t from the brain , or "forgot­ ten . " A simplified "loop" is shown in Figure 12 . 1 . B ecause loops are hypothesized to b e dyn am ic electrical and che m ical even ts (me ssages from dendrites to cell b o d ies to axons are electrical in n ature; chem i-

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cal s u b stances called transm i tters relay the messages across the synapses) , they are fragile and prone to electrical and/or chem ical d isrupt ion . For ex ample, H e b b (1 966) notes that when men tal patients are scheduled t o rece i ve electroshock therapy, they can be asked to learn a series of nonsense syllables j ust before the treatmen t . After patien ts h ave recovered from the confu sion that follows such shock treatments, they can b e asked how many syllables they remember. When s hock is given j ust after learn i n g , the typ ical result is that no retention is evi­ denced . When there is a delay, some retention is fou n d , and the s u bj ect shows consid erable savi ngs when relearni n g the list. This implies that short-term mem ory is s u sceptible to d isrupt ion i n i ts i n i tial stages but that it changes with time into a m ore durable form . Th is p rocess of ch a n ge is called consoli d ation; i t is the process whereby the dyn a m ic STM trace is converted i n to a structural LTM trace . Such a ch ange clearly does not occur all a t once. H e b b s tates that accord­ ing to con tigu ity theory, when neuron A fires a neu ron B, the A-B con n ection is stren gthened . Accord ing to reinforcemen t theory, however, a reinforcemen t must occur j ust after the firing for the bond t o be s tren gthened . I n any case, the slow progress of consolidation shows that the s yn aptic change th at stren gthens the A - B connection is only begu n by dyn a m ic events . The full process of con ­ sol id ation takes an hour or m ore . H ebb (1966) speculates that the consoli dation process involves either a structural change at the synapse (such as growth in the synaptic knobs) , or a narrowing of the synaptic cleft, or a b i ochem ical change in the two neurons i nvolved . Hebb notes the effects o f h ippocampal damage i n h um a n s and compares these to an imal stud ies . Fro m th is, he s p eculated that the h ippocamp u s is only n ecessary for the consol ida tion of com plex STM , and th at simple S-R learn in g can be consol idated through some sort o f b i ochem ical e ffect of rei n forcement which keeps the loops active long enough to "cemen t" the synapses involved . Th us, H e b b sees memory a s involv i n g a transition from a dynamic STM form (wh ich i nvolves activation traveling aroun d lo ops) to a s tructural pa ttern of altered synapses (wh ich occurs gradu ally in the process of c onsol i d a t i on) . S i nce m e m ory in this theory is stored in patterns a nd no t in i n d i vid ual p igeonholes or n erve cells, it is reasonable to assun1 e th a t n1 en1 ories are wi d ely represented througho u t functional regions of the b ra in rather th an b e i n g stored separately i n spec i fic locations . As noted, when mental patients are given electroshock therapy ( also called el ectroconvulsive therapy, or E CT) , they s how a loss of memory for learning that occurred j ust before the shock (retrogra de amnesia) . This would seem to i mply that d isru ptive electrical events s top the process of consol i d ation and hence preven t new STM s from ever becom ing s tructural LTM s . There are some co mplications o f ECT (called ECS, or electroconvulsive shock, when a pplied to an imals, since no one pretends that shock is g i ven to animals as therapy, or for their "own good " ) , however, that m u s t be note d . H ines and Paolino (1970) fou n d th at wh ile rats given ECS after learn i n g a passive avo i d a nce response show the expected amnesia for the avo idance res p onse, their heart rates are accelera ted in the test situation , showing some evi dence of cond itioned fear. This m ight b e explained as ei ther a function of fear cond itioning that takes place in lower brain centers not affected by the shock, or as a sign that consolidation is

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faster for autono m ic responses . Q uarterm a i n , McEwen, a n d Azmitia ( 1970) fou n d that when animals tra ined to avoi d shock were g iven ECS 1 second later (ECS is m ost effective if g iven very soon after the original learn ing) , the expected loss of memory of the avo idance response resulted . B ut if the an imals were g iven " rem inder foot-shocks" o u tside the test s i tu a tion, or if they were g iven repeated opportun ities to d isplay the " lo s t memory of the avoi dance respon se, " recovery from the apparent retro grade amnesia occurre d . These results could be inter­ preted to mean that som e consol idation had occurred almost i m m ed iately and the test procedures provided enough stimulat ion to allow these partially con­ sol idated traces to compl ete the consoli dation process, thus m ak in g it appear as though the memory " returned . " Alterna tively, it could be that ECS d isru p ts retrieval of the memory rather than block i n g consoli d a tion . This retrieval h y­ pothesis has been s up ported by M e yer ( 1972) . A nother alternative to the " in terference-with -consol idation" interpretation of the effects of ECS h as b een offered by N i elson ( 1968) and DeVi etti an d Larson ( 1971) . These authors have s uggested th at since the ECS p roduces a ch ange in brain state , m aterial learned when the s ubj ect is i n a normal brain state is not retr ievable . Thu s, retrieval is depen den t u pon the state of the animal's bra in . DeVietti and Larson ( 1971) fou n d that if the animals were tested fo ur d ays after the ECS ( presu m a bly when their b ra i n s h ad returned to the same state as d u ri n g the origi n al learn in g) , fear memories were again retrievable . Th is p henomenon , called state- dependent l earning, cou ld be offered as an alternative explanation of the results of the K Cl (cortical spreading depression) s tu dies presented earli er . That is, i n s tead of proving the existence o f subcortical learn ing, the results o f these stud ies could b e i nterpreted as demonstrating that the d epressed animals tested in a non d e­ p re ssed (whole-brain ) state were unable to retrieve the ir m emories of the alterna­ tion response because the state o f their b rains h a d been altered . Most of ECS and h uman shock therapy s tu dies, however, do support the " i nterference-with -consol idation" h ypothesis, at least w i th responses m e diated by the central n erv o u s system . Many o f the anomalies d isappear if we think of consolidation as a process that begins immediately after the learn ing experience and then may take several hours to complete. Retrieval d i fficulties may reflect partially consolidated memories wh ich can be m ore fully consolidated e i ther by remi n d er cues or by t i m e . State- dependent effects m ay b e due to the fact that the cues ( i ncluding the sensations in duced by ECS) are p art of the total experience of the s u bj ects . One could hypothesize th at since the memory is only weakened by ECS ( assu m i n g that som e consolidation h ad occurred j u st prior to ECS) , sti m u ­ l u s con d itions unl ike those of train i n g would interfere with retrieval; on the o ther h an d , cues associated w i th training (a non -ECS state) would fac ilitate retrieval. For H e b b , t h e f i rs t stage of t r u e ( s h ort-ter m , or i m m e d i ate) m e m o ry c o n si sts o f m e ss a g es t rav e l i n g a r o u n d reverberat i n g l oo p s o f n e u r o n s . S T M is easi l y d i s­ r u pted , o r preven ted f r o m c o n s o l i d a t i n g i n t o LT M , by E C S , w h i c h p r od u ce s a retro g r ad e a m n e s i a . T h is a m n e s i a d oes n o t e x t e n d t o p r i m i t i v e fear re­ s p o n ses, m ay be a t l east p a rt i a l l y revers i b l e , a n d m ay reflect ECS s t i m u I u s p ro p ert i e s or state-d e pen d e n t l e a r n i n g .

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Even i f most evi dence favors Hebb's contention that STM is a dyn a m ic event which can be interfered with to prevent or weaken consol idation , what of h is theory that LTM consists of altered syn apses? R a isman ( 1969) has shown that synaptic connections have the ability to change (at least, in the septal n uclei of rat brains) . Frazier, A ngelett i , and Bradshaw ( 1 972) h ave shown that new synapses can be forme d by peripheral neurons (sproutin g) in the p resence of a naturally occurrin g substance (nerve growth factor) . Rosenzweig and colleagues ( 1967) h ave shown that rats placed in enriched environm ents not only h ave m uch heavier brains than rats reared i n stimulus-poor env i ronments, they also show m uch faster learn ing. Morrell (1961) h as demonstrated that treatin g one cortical hem isphere with alum inum hydroxi d e cream results in an irritative focus, with tangled and d isordered nerve fibers . Interest i n gly, a similar " m irror focus" appears in the untreated hem isp here ( presum ably by transfer of inform a­ tion across the corpu s callosum) , indicatin g tha t p atterns of neuronal synapses can be altered by dynamic factors (th at is, by transfer of the "exper iences" of the chemically treated hem isphere) . Taken together, these results suggest that e i ther changes i n synapses or growth of new synapses can occur as the result of experiences and that these chan ges m ay represent the anatomical basis for con­ sol idated , or long- term , memory . This i n turn leads one to speculate that p erh aps the old popular belief that men tal exercise strengthens the b ra i n j ust as physical exercise strengthens the m u scles might be correct after all . A few years ago, anyone s uggesti ng that th inking and learn ing m ight m ake the brain grow would h ave been laughed right off the s peaker's podium ! Seve r a l l i nes o f ev i d ence s u g g est t h at LT M c o u l d c o n s i s t of a l tered syn a ps e s . I t h as b e e n s ho w n t h at d y n a m i c events ( s u c h as t h ose o f S T M ) c a n a l t e r syn a p t i c con n e ct i o n s a n d t h at h i g h-s t i m u l at i on e n v i r o n m en t s l ead t o i n ­ c re as es i n c o rt i c a l we i g h t .

M orrell (1961) reported another in teres ting find i n g . H e found that the ribonucleic acid (RNA) obta ined from the " m i rror focus" was consider­ ably d i fferent from that fo und in normal bra in tiss u e . This s uggested tha t d ynamic events in the b ra i n could alter the kinds and amo unts of RNA i n the bra i n . RNA is the molecul e that takes the i nstructio ns mapped onto DNA m olecules (the genetic code) and uses then1 to d irect protein syn thesis . RNA molecules are very large; they consis t of thousands of atoms arranged into fo ur types of base su bstances and connectors . To those search ing for a chem ical s u bstra te of memory, RNA is i n tr i gu ing because i ts base sub­ s tances can be arranged in many con1 b inations; an impressi ve amount of infor­ ma tion could be coded in sequ ences of such combina tions . Th is great s torage capac ity is on e of the reasons why n1a ny researchers h ave exam ined RNA as a possi ble element of learn ing and memory . The role of bi ochem ical factors in memory can be viewed from two perspect i ves : (1) that m emories are coded d i rectly onto RNA or protein molecules and th at somehow th is cod ing is s u bse­ q u en tly retranslated i n to altered patterns of specific neuronal activi ty , or (2) th at

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I ntense l ight

T maze

C rossed eyes

Mouth at end of stomach tube

Fig u re 1 2 . 2 A fla tworm (pla n a ria) ma king up its mind i n a T maze. Since most of th e n ervo us system is posterior to the b rain , th is m a y be a diffi c u lt pro cess . Th e w orms do learn to choose on e of the maze a rms con sis ten tly , either beca use of th e in tense ligh t (a versive US ) or beca use of foo d rewa rds (ins tru men ta l lea rning ? ) .

R N A or o ther macro m olecules (such a s proteins) are somehow involved i n form­ ing altered or new synapses . L e t us examine the first perspec tive . In 1964, Hyden and Egyhazi found that rats trained to u se the i r nonprefer­ red paws to obtain food showed b oth h igher amounts and d ifferent types of RNA in the half o f their cortex that controlled that paw. Control an imals who used their preferred paws (and hence required no new learn ing) showed no changes in RNA . S i m ply showing changes in RNA as the result of learn ing, however, does not explain whether the RNA m olecules carry the memories, or if the changes in R N A reflect changes in s tructu ral ch aracteristic s o f synapses or o ther b rain elemen ts . D ingman and S p orn ( 1964) found th at inj ection of a che m ­ ical that i nh i b i ted R N A synthesis interfered w i th formati on o f n e w m emories but had no e ffect on old memories . These results could b e interpreted as e ither showing the production of RNA " m em ory m olecules" to be necessary or as showing that RNA is som ehow involve d in structural changes during consolida­ tion o f STM to LTM . Again , we are unable to determine the exact role of RNA i n m em ory . How, then , could i t be shown that R N A i s indee d the memory mole­ cule? One m ethod m i gh t be to transfer the memories of a task encoded on the RNA o f one animal to another animal . If the second ani mal showed si gns of " knowing" the solution to a task to which i t had never been expose d , that would be sol id evi dence that RNA is a " m e m ory m olecule . " The first experim ents to d em on s trate this were conducted by James McCon­ nell and h is s tudents, u sing flatworms ( planarian s ) . First, they classically con­ d i tioned their an imals using shock as the US and a flash o f light as the CS . The trained worms were then fed to untrained worms . The untrained worms exh i b­ ited the cond itioned res ponses, ind icating that " m emory" had been transferred (McConnell, 1 962) . To prove that RNA was the critical element in the transfer, they then trained the planaria in a sim ple T maze (see Fi gure 12 . 2) and after­ wards fed only the extracted RNA to u ntrained worms . Again, transfer of learn-

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i n g was impl i ed by the s u per ior perform ance of worm s fed " tra ined RNA' ' when com p ared to the performance of worms fe d " u n trained RNA' ' (M cConnell, 1966) . Though McConnell's results seemed to demonstrate th at mem ori es could be trans ferred by transferring RNA, criticisms were not long in com i n g . H artry , K e i th- Lee, and Morton (1964) fou n d th at R N A from worm s given random shocks was j u st as effect ive in facilitatin g shock a vo i d ance as that from worm s trained to avoid shock. These results suggested th a t p erh aps R N A sim ply pro­ duced a sensi tization effect . M cC onnell (1968) replied to s u ch cri ticisms by s u g ­ gesting th at the n egative results represented methodolo gical problems o f rough h andling procedures and fa ilure to m ax im ize m o tivation . In any case , attenti on then turned to attemp ts to replicate McConnell's tran s fer effects i n m am m als . An early successfu l example of such transfer was perform ed by Jacobson in associ a tion with Babich and Bubash (in J acobson and Schl ecter, 1 970) . They trained rats to approach fee d i n g places only when a light was on (a S 0) . These donor rats were then sacrificed; the ir RNA was extracted and i nj ected into the abdom in al cavi ties of rec i p i ent rats, and these rats were, in turn , tested on a light and on a tone discrim ination task. If the transfer effect was really sensitiza­ tion, it would be expected tha t the reci pients would ap proach the foo d c u p d uring ei ther tone or li ght presentation. The results were t h a t the light- tested rats approached m ore d urin g light flashes, offering str ong s u p port for the RNA transfer hypothesis. Another group of rats, tra ined to ap proach the foo d cup when a click was sou n ded, suffered a similar fate. The reci p i ents of their RNA approached the food cup fo ur times as o ften when a click was sou n d e d as when a light was flashe d . At th is p o in t , some of you are no d o u b t considerin g gri n d ­ ing u p p rofessors a n d extracting the ir ( presum ably) h ighly trained R N A a s a shortcut to absorbi n g knowledge. But wai t ! As you sho u ld have s u spected , n u merou s negative reports challenging these fin d i n gs soon appeared (reviewed in Brown , 1976) . In addi tion , Lu ttges and colleagues ( 1 966) , u sing rad i o active tracers, fou n d that most abdo m i n ally inj ected RNA was secreted before reach ­ i n g the bra i n . I n sp ite of many successfu l replications (over 50 are revi ewed in an art icle by Byrne, 1970) , the whole iss u e o f transfer o f n1 en1 ori es through transfer o f RNA is st ill in doubt . Chapouthier ( 1 973) , revi ewi ng the con fl icting reports, conclu des that the successful studies u sed a coarse RNA ex tract, while most unsuccessful attempts at repl ica t i on u sed a pure RN A extract. This sug­ gests that i n1 p u ri ties (such as prote ins) may actu ally h ave carri ed the mem ory i n formation . Some s u p port for the protein memory hyp othesis has come from the labora­ tory of Ungar (1 966 ) , who hab i tu a te d two gro ups of rats to e i ther a loud no ise or a stron g pu ff of a ir. Followi n g hab i tuation , the bra i n s of the rats were homogen ized an d the resulting prote in extracts were inj ec ted in to n a i ve reci p ­ ients . The rec i p i ents habi tuated n1 ore rap i dly to the stimulus to which the donor h a d been expose d . In 1970, U n gar reported the isol ation of an extrac t obtained from the bra i ns o f n1 ice that had learned to avo i d shock by leavi n g a dark com partmen t . When i njected into n a i ve mice, i t cau sed them to leave the ir norm ally preferred dark cham bers, in the absence of experiences with aversive

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consequ ences . U ngar named th is extract scoto phobin (a G reek \vord mean i n g "fear o f the d ark") . O ther s u p p ort for the prote in hypothesis came from the work of Baron d es and Cohen ( 1966) . They reported rapi d forgetting of a maze h a b i t in m ice i nj ected w i th puromycin (an antibi o tic wh ich i nh i b i ts protein synthesis) . The same researchers, however, fou n d no d isruption of consolidation when cyclohexam ide (also a p ro te i n synthesis i n h i b itor) was i nj ecte d . Cohe n , Erv i n , a n d Barondes ( 1 966) offered a n explanation o f this d iscrepency . Puromycin i n ­ duces abnormal electrical activ i ty i n the h i p p ocampus (which, a s w e have already seen, is i nvolved in consoli dation of comp lex m emori es) , wh i le cyclo­ hexa m i d e does not . Thus, the resu l ts of p uromyci n may reflect convulsion­ i n ducing p roperties which act like E C S , rather than a d irect i nterference w i th m em ories . The effects of puromycin can also b e reversed by i nj ections of sal i ne solu t i ons i n to the bra ins of the experim en tal anim als (reviewed in G ross m a n , 1973) . We are left w i th the conclusi on th at altho ugh prote i n forma tion m ay have some function i n memory, i ts exact role is u nclear and i ts statu s as the " s i te of engrams " is uncertain . A nother approach wh ich exam ines the rol e o f chemical factors i n m emory has concen trated on altered levels o f transmitter substances (wh ich carry m es ­ sages fro m axons to d endrites) . Deu tsch an d D e u tsch ( 1973) h ave looked for the engram in altered m echanisms of trans m itter s u bs tance s torage and release at syn a p ses . As the result of experience, these m echanisms m ight alter the effi­ ciency o f syn apses, and hence make certai n pattern s of neuron s b etter su i ted to conduct m essages in the fu ture . Drugs wh ich block the act i on of transm i t ters were fou n d to have selective amnesic effects . Scopola m i n e , wh ich blocks the n eurotransm i tter acetylcholi n e (AC h) , had no effect on memori es of experiences occurrin g less than 30 m in u tes before the i nj ec t i on . As the t i m e b e tween tra i n ­ i n g and dru g i nj ect i on increase d , the amnesic effects i ncreased , u nt i l almo s t complete am n es i a was produced w i th one- to three - d ay train in g t o i nj ecti on i ntervals . If the i nj ections were g i ven two wee ks after tra in i n g , m em ory of the tra in i n g was i mproved or unaffected . Th is was presuma bly becau se the drug acted to block m ore recent, i nterferin g m em ori es . Deu tsch and Deu tsch ( 1973) reported further : Drugs that b locked the enzym es (chol ines terases) that normally d estroy A Ch not only raise d the levels of A Ch b u t also h ad effects o pposi te to those of scopolam i n e . One- to three - d ay-old m emories were u naffected, wh i le one- to two-week-old m e m ories were almo s t totally lost. Wi th still older m em ories, the amnesic effects d i m i n ishe d . These results su ggested that conso l i ­ d a tion w a s a much slower process th an i n d icated b y the results o f the E C S s tud ies . Deu tsch an d Deutsch's fin di n g s m a y , however, reflect losses in abi l i ty to recall newly conso l i d a ted m em ories rather th an i nterference w i th consoli da­ tion per se . These resu lts do lend tan gen tial s u pport to the ges talt a n d inform a ti on -processin g v i ew th a t memories con tinue t o change a n d s trengthen long after b e i n g learned . Severa l ty pes of m a c ro m o l e c u l es h ave been i n ves t i g ated i n t he sea rc h f o r t he e n g ra m . I t h as been s ho w n t h at i n c reased a n d a l te red R N A i s p ro d u ced by l e a rn i n g , a l t h o u g h t he t he o ry t h at m e m o r i es c a n b e d i re c t l y t ran sfer red by

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R N A i nj e c t i ons is d is p u ted . D ru g s i n te rfe r i n g w i t h p ro t e i n synt hesis c a n a p­ p a re n t l y b l o c k c o n so l i d a t i o n , res u l t i n g i n a m n es i a . M e m o ry t ra n sfer by p ro­ t e i n t ra n sf e r is a l so d i s p u ted . D r u g s i n terfe r i n g w i t h t ra n s m i tt e r s u b s t a n c es c a u s e a m n esi as- p er h a ps by b l oc k i n g reca l l of n ew l y f o r m e d m e m o r i es .

Let u s summarize the d a ta presented thus far . The process of learn i n g seems to begin with selective attention, which res ults i n som e dyn a m ic acti va tion of gro ups o f neurons . In intact m amm als, these are cortical neurons, and the activa­ tion consists of cells sen d i n g m essages across the ir synapses to other neurons wh ich, i n tum , send messages onward in a cha in o f events that eventually reexcites the ori g inal neurons . Th is short-term m em ory trace is prone to d isru p ­ tion by electroconvuls i ve shock o r by t h e waves of depression pro d uced by K C l when it i s applied to the surface o f the m em b ranes over the cortex . Th is pattern of activation stimu lates the gradual formation of a structural representation of the m em ory, known as long-term m em ory or the engram . The transformation of STM to LTM , called consolidation , probably i n volves some ch anges in the synapses, j ust as Hebb pre d ict e d . During th is process, altered R N A and new prote ins are produced , and experim ental m anipulations wh ich i nterfere with e ither RNA or protein production can prod uce amn esic effect s . Some properti es of m emory may be coded on RNA or protein molecules, although the extent to wh ich this occurs is debata bl e . Memories wh ich are , fairly well along in the process of consoli d a tion may be blocked by agents wh ich in terfere w i th trans­ m itter functions . Engram s seem to be diffu sely represen ted throughout whole reg ions of the cortex , rather than being coded on in divi d ual neurons, and the h i ppocampus plays som e vi tal role in the consoli dation of complex in forma tion . F i n ally, we know tha t the total storage cap ac i ty of LTM is very large an d that memories th a t appear to have been los t can , u n d er certain cond itions, b e bro ught back. Any theory that professes to b e a com prehensive theory of men1 ory must incorporate most of these ideas and research res ults . It must provide an explana­ tion for the s urvi val o f engrams in the face of extensive cortical damage (recall the work of Lashley) , and it must take i n to account the large storage capac ity o f LTM (Reynolds, 1974 ) . O n e theory wh ich i s able t o accomp l ish this i s the holo­ gram* ana logy theory proposed by Karl Pribran1 (197 1 ) . Th is theory sho uld not be in terpreted as s ta ting tha t we l iterally create hologran1 s in our heads, but rather that learn i n g and memory involve processes similar in function to those in­ volved in the creation and dep iction of holo gra m s . Another advan tage of the *

H ologra m s or hologra p h s are the pro d ucts of a speci al photogra p h ic process ca lled holo­ g ra p h y i n wh ich la ser beam s ( u su a lly) a re u sed to expose the photogra ph i c plate (the hologra p h ) . U nl i k e t he photogra p h s created in norm a l photogra p h y , hologra p h s con tain i n each o f thei r parts so me i n form a t i on from each part of the scen e photograp hed . Con seq u en tly, when v i ewed w i t h norm al l ig h t, hologra p hs look l i ke collect i on s o f wavy l i n es ra ther th an p ictu res. I f vi ewed u n d er laser l i g h t , a th ree- d i m en sional i m age appears i n fron t of the hologra p h ; th is i m age chan ges i n a ppearance when vi ewed from d i fferen t angles . When a hologra p h is cut i n two, each h a l f w i ll s how a l l the ori g i n a l scen e, rather t h a n half the scen e, as when a con ven t i on al photograph is b isected . See the appen d ix to t h i s chap ter for a m ore d etai led descri p t i on of hologra p h y , or see Pribram 's art icle i n Psychology Today (1971 b ) .

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m o d el o f learn ing and m em ory developed by Pribram is that it provides n e u rophysiological explanations for the various s tages of m em ory p resented in the d iscussion o f Norm an's inform ation-processing theory. To the extent that Pribram's theory accurately reflects the d ata on b ra in m echanisms during learn­ i n g , it p ro vi des s u p p ort for the multis tage vi ew of learning and m em ory . Pribram's Theory o f Leaming and Memory : Holograms i n the Head

As we saw in the d iscussion of Norm an's informa tion-processing t heory, the first step in learn in g is p ay i n g a ttention , which is a h ighly selective p rocess . A complex reflex correlated with p aying attention is called the orienting reflex, or the "what-is - i t?" reflex . Sokolo v ( 1963) fou n d that any chan ge i n a repeate dly presented s ti m ulus configuration , i ncluding a reduction of i n tensity, could elic i t t h i s reflex . H e concluded t h a t the ori enting reflex w a s triggered b y a m ismatch b e tween i nco m i n g i n formation and some p atterned memory trace, or neuronal model, of a given situation . Thus, attention results from the simu ltaneous acti­ vation o f an i nternal pattern and the e ffects of the incom ing i n form ation . The i nteraction of these two sou rces of activation is t he firs t step in form ing new m em ory traces . Pribram ( 1971 b ) has noted that u s ually two laser b eam s (or two halves of one beam split by a m irror) are needed to create a hologram , or a holograph ic "m emory , " o f t he obj ect exposed to the laser beam s . The i nteracti on b e tween these two sources of "ac tivation" creates a pattern , and all the informa­ tion about the o bj ect vi ewed is coded in each part of th is p attern . Why not, Prib ram concludes, consider the two sou rces o f activa tion eliciting the orientin g reflex as analogou s t o the two laser beams?

A t ten tion a n d Habitua tion When a sensory i n p u t m a tches the internal neuronal model , no n ew learn i n g occurs . I n s tead , the electrical responses recorded from the retina of the eye a n d from the visu al relay s tations s how decrem enting ( decreasing) responses to m onotonou s visu al s tim ulation ( Pribram and M cG uinness, 1975) . Only changes i n stimulation trigger increased responses from these sensory elemen ts, and t h is m ay represent an ini tial s tage of filtering sensory informa ti on s tore (S IS) , a type o f information s torage in Norm an's theory that occurs before true STM . This decre m enting of sensory responses to repe titive stimuli is called h ab i tu ation; i t i s the p rocess b y wh ich w e learn n o t t o p a y a ttention to redund an t o r irrelevant cues . Like o ther form s of learn ing, habi tu ation begins w i th a STM p hase and then progresses to a m ore p erm anent form o f m em ory . U nlike normal LTM , however, habi tu a tion u s u ally d ecays progressively o ver time p eriods as long as six m onths ( Pribram , 1971b) . Pribram and M c G uinness ( 1975) also note that a m ore com plex typ e of p atterned hab i t u ation occurs in the visu al cortex . I n this type of habituation, som e cells i n itially fire at h igher rates (increment) , wh ile o thers fire at lower rates (decrement) . These a uthors suggest that this complex p at tern o f changed firing rates to repetitive s tim ulation represents the i n i tial, or STM , p h ase of form ing a neuronal m odel of the ongoing environment. E ventu­ ally, t h is altered s ta te of activity is consoli d a ted i n to a m ore d urable neuron al

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m od el . When reexposed to environments represented by the neuronal model, the organ ism again shows the behavior associated with habituation-that is, a lack o f b rain aro usal and an absence of the orienting reflex . Paradoxically , even forms of m is match with the neuronal model cause d by removal of the repetitive stimuli or lowerin g of their i ntensi ty result in dishab itu ation and a return of the orienting reflex. Pri b ram (1971 b ) reports that when a very noisy elevated railway line in N ew York was torn down, people slee p i n g in a part ments near t he line suddenly awoke and called p olice to report " some stran ge occurrence . " The call s coinci ded with the former sche dule of the trains, and the strange occurrence was, of course, the deafen i n g silence that had replaced the expected sounds o f the trains . The fact that the peop le had learned to ignore the so unds of the trains illustrates a long-term form of complex habituation, and their arousal reaction s to the lack of s uch sounds illustrates dishab ituation . This s uggests that the people' s neuronal models of repeti tive n i ght soun ds h a d even reflected t he timing o f the trains, an d that the mismatch with that m o d el cause d by the closing down of the line h a d e l icited the orienting reflex an d arousal . The types of h ab i tuation j ust discussed may b e related to the stimulus filters responsible for selective attention effects . Recall the discussion of select ive atten ­ tion from the section on inform ation-processing theory i n the las t chapter . We presented evi d ence that when a s u bj ect was exposed to two simultaneou s m e s ­ sages, h e o r she w a s only able to report b ack the in forma,tion contained in on e o f these m essage s . When the gross physical ch aracteris t ics of the u n attended mes­ sage were changed rad ically (as from a m ale to a female voice) , however, the subj ect was aroused by the change and able to report i t . Somehow the s u bj ect had m on itored the physical ch aracteristics of the u n a ttended message on an unaware leve l . For the su bj ect to detect the change in type of stimuli, som e part of the brain m u s t have had a model of the general stimu l u s characteristics of the sou n d before the change . When the sou n d no longer matched this m o d el , he or she began to p ay attention to the so u n d on a consciou s leve l . Norman suggests that lower- level filters reduce the intensity o f such " u n im portan t messages, " or atten uate the m , so that witho u t a radical change of the type j u st d escribed they are not strong eno ugh to lead to aware attention . Th is attenuation by Norman's "stim ulus-ch aracteris tics filters" could be created by the decremen ting of sen­ sory responses to repeti tive stimu lation reported by Pribram and McG u inness (1975) . It was also reported that when " h i ghly meaningfu l" words (like the s u bj ect's name) were embedded in the un attended n1essages, the s ubject be­ came aware o f them . This " filter for mean i n g" process m igh t be explained by Pribram's and McGu inness's pa tterned h abi tuation, wh ich they cite as evi dence of the form ation within the b ra i n of a new neuronal model. This model of the p resen t state of the person's envi ronm ent, along with the altered s tate of the rece ptor processes, consti tu tes a n1emory s ystem which operates on an unaware level and wh ich inhibits the orienting reflex when the organ ism is exposed to condi tions matching the neu ronal model . Thu s , h ab i tu ation of the two types j u st described is a type of unaware learn i n g of what not to pay attention to and what not to p u t into normal long-term memory . This learni n g occurs whenever the orienting reflex is not followed by unu sual or conseq u ential even ts and m ay

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i nvolve the temporary arousal o f some regions of the cortex while the appropri­ ate neuronal model is being formed . Th is n euronal model then acts to i nhibit the orien ti n g reflex and conscious awareness while s timulus cond itions remain u nchange d . I n this model o f selective attention, the subj ect monitors repetitive and/or meaningless stimulus events at an unconscious level . The process by which monitoring shifts from h igh - involvement aware a ttention to unconscious m on i ­ toring is habi tuation . The unconscious monitoring system scans incoming i n ­ formation and compares it t o a relatively short- term model of the existing world . Whenever new information doesn't fit this n euronal model (either because o f a radical change i n stimulus characterist ics or because o f having a h i gh "mean i n g value" through fitting existing long-term memories o r pred icting important events) , the orienting reflex and conscious attention result. This mechanism has the result o f ensuring that we s pend most of our energy on importan t events and form new long-term memories only of such events . This protects us from filling our p ermanen t memory banks with a multitude o f trivi al u nits of information . P ri b ra m s u g g ests t h at o u r b ra i n forms n e u r o n a l m od e l s of t h e w o rl d . W he n st i m u l i f i t t hese m o d e l s a n d d o not l ea d to c o ns eq u e n c es , h a b i t u at i o n o c c u rs . D i fferent types of h a b i t u at i on , a n a l og o us t o t h e d i ffe rent s t i m u l u s f i l te rs i n i n fo r m at i on p ro c essi n g , s e rve t h e s a m e p u r p o s e-t h at of " t u n i n g o u t " i r­ r e l ev a n t i n fo r m at i on f r o m aware atten t i o n of t h e type asso c i ated w i t h t h e o r i e n t i n g ref l e x . U n aw a re s c a n n i n g of h ab i t u ated st i m u l i , h o wever, c o n t i n u es u n t i l a m i s m at c h i s d etected , c a u s i n g d is h ab i t u at i o n .

Pribram a n d McG u in ness ( 1975) h ave tried t o relate habi tuati on a n d mon i ­ toring mechanisms t o the functi ons of v arious p arts of the bra i n . Habituation of the type that inhib i ts the ori en ting reflex seems to depend upon activities of the a mygdaloid nuclei which lie d eep in the temporal lobes between the hippocam­ pus and the brainstem . When these nuclei are removed , the experimental ani­ mal shows an ever-continuing orienting reflex and cortical arousal wh ich never h ab i tuates . During the orien t i n g reflex , numerous body and visceral responses (such as i ncreased heart rate) can be ob served . These components of the orien t­ i n g reflex can be abolished by lesions to the top and sides o f the frontal lobes . L e t us now review the functions of the frontal lobes i n selective attention and learn ing. L uria ( 1970) iden tifies the frontal lobes as the place where plans and strate­ g ies are first formed . These take the form of neuronal m odels "of the possible , " or ab stract thinkin g . These neuronal models, like o ther neuronal models d is­ cu ssed so far, are related to short- term memory i n that they are assumed to consist o f altered s tates o f electrical activity ori ginating i n the functions of n euron s . M iller ( 1972) reports that damage to the frontal lobes does not result in loss o f memory o f formerly learned ab stract i deas (which are assumed to be stored i n engrams or relatively p ermanen t s tructural form i n the back half o f the cortex), but does p revent the learn ing of new ab straction s . Pribram suggests

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M od ern Con tendfrs

that the frontal lobes are the place where ongoing events are com pared to the h i ghes t types of neuronal models, w h ich consist of expectancies about se ­ q u ences of stimul i . Thu s, they relate successive events to pre d ic ted seq u ences and coordinate d i fferent channels of i nform a ti on origina ting in different types of sensory cortex so tha t these different activated reg i ons do not i nterfere wi th each o ther . A n example of this functi on in g m i gh t b e tu rn ing your head towards a su dden m ovement and being prepared to experience the sou n d assoc i ated with that movemen t . When events do not follow o u r exp ectancies, we experience surprise, which manifests i tself i n b oth arousal of o ther reg i ons of the bra i n a n d in the p hysiolo gical responses associ a ted w i th the orien t i n g reflex . This i n ­ creased arou sal, i n tu m , creates a state of aware attention and a readiness e ither to act or to m e m orize i n formati on about the u n u s u al even t . We have alrea dy seen that damage t o the frontal lobes of animals i ncreases distractib ility. When such animals are faced w i th tasks requ iring delayed re­ sponses, they seem u nable to prevent even ts occurri n g du rin g the delay period from i nterfering with STM related to the ori ginal learn i n g . Pribra m ( 1971a) suggests that such animals can not form neu ronal models wh ich would pre d ict that their origi n al responses will still be successful after a delay . I n o ther words, they do not d iscriminate the events occurri n g during the delay from events before (original tra i n i ng) and after ( m ak in g the delaye d resp onse) because they have no neuronal m odel predicting the en tire sequ ence of events . This is be­ cause they are u nable to coordinate multiple ch annels o f inputs (the i nputs arisin g from the events of d i fferent p arts o f the entire sequ ence) . For such an i ­ mals, every event i s a totally new event rather than p art o f a n ongo i n g seq u ence and so every even t calls for atten tion . This is the reason for the increase d d i s trac­ tib i l i ty . S i nce every event is attended to, no one event stands o u t enough to call forth the body signs of the orien t i n g reflex . To conclude th is discu ss i on o f Pribram's theory o f the anatomy o f learn i n g a n d a ttention, one m ore area of the b ra i n s hould b e men tioned . The hypothalam u s, which lies at the top of the bra i n s tem, seems to coordi n a te most m ot ivations and contains powerful " pleasure" an d "pain" areas . Th is area be­ comes active during periods of uncerta inty (m ismatches between i npu ts and neuronal m odels) and may provide the m otiva tion to reduce u ncerta inty . Prib­ ram notes th at damage to the p art of the hypoth al am u s known as the m a m m il­ lary bodies seems to reduce the incentive to recall previ ously learn ed material (1971a) . Pribram c i tes s tu d i es showing that the effects of these o perations are exerted on central ( h igher) mechan isms con trollin g selective attention and not on sen­ sory sen si ti vi ty or response mechan ism s . These h i gher mechan isms, in tu rn , determ ine what gets reg istered a s STM or, followin g the hologram a nalogy, what starts the operations o f the neuronal equ ivalent of the laser beams which fin ally crea te a holograp h . Pribram summ arizes data showi n g that when two i n p u t signals are sepa­ rated by an i n terval, the first acts to start the formation of a neuronal model (similar to the first laser beam i n holography) and the second determines what the organism will do (form a memory or m ake a response) . Paying atten t i on is

371

Th e B io logical B ou nda ries of Lea rn ing

Parietal lobe

(Front)

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�ssoc iation areas)

· �� r--

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H i ppocampus

Occ i pital lobe (Visual cortex)

(Auditory cortex) Temporal lobe

� � )'\.__ Amygdala

(Back)

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