An experimental investigation of the effect of varying the time between the onsets of the conditioned and unconditioned stimuli on the conditioned eyelid response

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a® M X p m im M T M , m r m T i a i m m T i m m m s s m ebb a r n v m UHCOHDX TIOMIB G O M D IfX O K D m

of m i effect of tabyxhg w of t m oombitxoieb a w B T i m h l OH fill i B lUGBOPOHSS

J o h n A rth u r M yers, J r .

A dissertation s u b m itte d in p a r t i a l f u l f i l l m e n t o f th© r e q u ir e m e n ts f o r th© d e g re e o f D o cto r of P h ilo s o p h y , i n th e D ep artm en t o f P sy ch o lo g y in th e G ra d u a te C o lle g e o f th© S t a t e University o f Iowa A ugust 1950

ProQuest Number: 10598598

All rights reserved INFORMATION TO ALL USERS The quality o f this reproduction is d e p e n d e n t upon th e quality o f th e c o p y subm itted. In th e unlikely e v e n t that th e author did not sen d a c o m p le te manuscript an d there are missing p a g e s , th e s e will b e n o ted . Also, if material had to b e rem o v ed , a n o te will in d icate th e d eletion .

uest. ProQuest 10598598 Published by ProQuest LLC (2017). Copyright o f th e Dissertation is held by th e Author. All rights reserved. This work is p ro tected again st unauthorized cop yin g under Title 17, United States C o d e Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106 - 1346

~ \Y \h o .tW \L V i

A G m m iM m m m The w r i t e r w is h e s to e x p r e s s h i s s i n c e r e a p p r e c ia ­ t i o n to D r. K enneth v/. S pence f o r h i s s t i m u l a t i n g c r i t i c i s m th ro u g h o u t th© c o u rs e o f t h i s i n v e s tig a tio n * to D r. Ju d so n S« Brown f o r h i s s u g g e s tio n s d u rin g th© p r e p a r a t i o n o f th e m a n u sc rip t* and to Mr. G eorge S . B a rk e r f o r h i s t e c h n i c a l a d v ic e #

T I B I I OF COOTMOS

Pag© I n t r o d u c t i o n * ...........................

# * • • * ♦

1

P u rp o se o f th e E x p erim e n t • • * « » , * • * •

4

E x p e rim e n ta l Method*

• . .

..............................................

S u b je c ts * ................... . A p p a ra tu s • * » . « * * * * ............................ . C o n d itio n in g P ro c e d u re * * • * • • • • * • • * R e s u l t s and D is c u s s io n • * * # • * . • * * # » » * E x p erim en t w ith Vibrator a s th e U n c o n d itio n e d S tim u lu s * * • * # * » * * • * » • » * * S u p p lem e n ta ry E x p erim en t w ith A ir P u f f a s th e U n c o n d itio n e d s tim u lu s * . # « • • * • . Summary* . » * « . . * «

. * . * • «

5 , •

5 0 7 11 11 19 30

A ppendix A • • • . * ...........................

34

A ppendix B ........................... *

35

R e fe re n c e s , . ,

43

...........................

ill

tabu

o f f ig u r e s

F ig u r e 1

2

5

4

5

6

p ag e P e r c e n t o f C o n d itio n e d R e sp o n se s in Sue* © easlv e B lo ck s o t f e n t r i a l s " f o r 't h e 5G0, 1 000, 1500, and 2500 Millisecond C roups* * •

12

I n c r e a s e s i n :P e r c e n t o f c o n d itio n e d R e sp o n se s in " S u c c e s s iv e B lo ck s o f Ten T r i a l s o v e r .th e F i r s t B lo ck f o r th e 5 0 0 , 1000, 1500, and 2500 M illis e c o n d G roups* * * * * * * * *

15

l e v e l o f C o n d itio n in g a s a F u n c tio n o f th e 3 e-S u I n t e r v a l , U t i l i z i n g th e 3c and Su C o n tro l D ata

IS

P e r c e n t o f C o n d itio n e d R e sp o n se s i n Suc­ c e s s iv e B lo c k s o f Ten T r i a l s ' f o r th e 500 and 2500 Millisecond G roups o f th e Second E x p erim e n t

22

I n c r e a s e s i n P e r c e n t o f C o n d itio n e d R esp o n ses in ,S u c c e s s iv e B lo c k s ,o f Ten T r i a l s o v e r th e F i r s t B lo ck f o r th© 500 and 8500' M illis e c o n d G roups o f th e Second E x p e rim e n t. . . . . . .

24

l e v e l o f C o n d itio n a© a F u n c tio n o f th e S c Su I n t e r v a l f o r th e G roups t h a t R e c e iv e d th© Y ib r a to r and T hose T h at R e c e iv e d th e A ir P u ff . . . . . . . . . . . . . . . . . . . .

26

iv

TiBil Of TABLES p ag e

T a b le I

A

B

C

B

&

P

G

H

In c re a se ® I n P e r c e n t o f Random E y e lid C lo s u re s o f L a s t 50 T r i a l s Over th e f i r s t 10 T r i a l s d u r in g th e 2 0 0 -5 0 0 , 2 0 0 -1 0 0 0 , 2 0 0 -1 5 0 0 , and 20Q-J&50Q M illis e c o n d I n t e r v a l s f o r th e S© and Y ib r a to r C o n tro l Croups* » » » . . * •

15

f r e q u e n c i e s o f c o n d itio n e d R e sp o n se s i n Suc­ c e s s i v e B lo c k s o f 10 T r i a l s f o r th e ' 20 Sub-" j e c t s i n th e 500 M illise c o n d © Y ib r a to r Croup

35

f r e q u e n c i e s o f C o n d itio n e d R e sp o n se s i n Suc­ c e s s iv e Block© o f 10 T r i a l s ' f o r th e 20 Sub­ j e c t s i n th® 1000 M illise c o n d © Y ib r a to r Group

36

f r e q u e n c i e s o f C o n d itio n e d R e sp o n se s i n Suc­ c e s s iv e B lo ck s o f 10 T ria l© f o r th© 25 Sub­ je ct© in th e 1 5 0 0 'M illise c o n d © Y ib r a to r G roup

57

f r e q u e n c i e s o f C o n d itio n e d R esponses---in Suc­ c e s s iv e B lo ck s o f 10 T ria l© f o r th e 25 Sub­ j e c t s i n th e 2500 M illis e c o n d s Y ib r a to r Group

m

Mean P e r c e n t o f S u b ject© G iv in g Response© I n S u c c e s s iv e B lo ck s o r 10 T r i a l s B o rin g th e 500 M illis e c o n d s , 1000 B iillise o o n & s , 1500 M i l l i s e c o n d s , and 25G0 M illise co n d © i n t e r v a l s f o r t h e C o n d itio n e d S tim u lu s , Y ib r a to r and P u f f C o n tro l Groups*

m

f r e q u e n c i e s o f C o n d itio n e d R esp o n ses In Suc­ c e s s iv e B lo ck s o f 10 T r i a l s f o r th e 10 su b ­ j e c t s in th e 500 M illis e c o n d s P u ff Group* • •

40

F re q u e n c ie s o f C o n d itio n e d R esp o n se s I n Suc­ c e s s iv e B lo c k s o f 10 T r i a l s f o r th e 15 Sub­ j e c t s i n th e 2500 M illis e c o n d s P u f f Group * •

41

S e m i - I n t e r q u a r t i l e R anges o f th e I n c r e a s e in P e r c e n t o f C o n d itio n e d R e sp o n se s Shown by Sub­ j e c t s i n th e 5 0 0 , 1 0 0 0 , 1500, and 2500 M i l l i ­ seco n d G roups o f th© F i r s t E x p erim e n t and i n th© 500 and 2500 M illis e c o n d G roups i n th e Second E x p erim en t • • » • • * • • • * * • * *

42

V

1

immmoTitm Among tlx© v a r i a b l e s t h a t a r e known t o a f f e c t th e s t r e n g t h o f a c o n d itio n e d r e s p o n s e i s th e tim e i n t e r v a l b etw een th® onset© o f th e c o n d iile n e d and u n c o n d itio n e d s ti m u li*

I n a f i r s t a tte m p t to f o r m u la te s y s t e m a t i c a l l y

th e m o la r law s o f b e h a v io r H u ll {&} h a s h y p o th e s iz e d t h e f u n c t i o n a l r e l a t i o n s h i p o b ta in in g b etw een t h i s v a r i a b l e and c e r t a i n m e a su re s o f r e s p o n s e s t r e n g t h , f o r ex a m p le , th e p r o b a b i l i t y o f r e s p o n s e © v o c a tio n .

He p o s t u l a t e d t h a t when

a s tim u lu s e n e rg y i s a p p l ie d to th© re c e p to r© o f a n organ ism a n a f f e r e n t n e u r a l im p u lse ( s tim u lu s t r a c e ) i s p ro d u c e d t h a t r is e © to a maximum i n t e n s i t y , and a f t e r some se co n d s reach©-© a z e r o v a lu e *

Gn4 th® b a s i s o f th e s e p a r t i c u l a r assum ption®

a s w e ll a s f u r t h e r a s s u m p tio n s , w hich i n e f f e c t s t a t e t h a t t h e p r o b a b i l i t y o f r e s p o n s e e v o c a tio n i s an i n c r e a s i n g mono to n ic f u n c t i o n o f th© I n t e n s i t y o f th e a f f e r e n t n e u r a l im p u ls e , i t i s e x p e c te d t h a t a© t h e 3 e-S u i n t e r v a l i s i n c r e a s e d from z e ro to a c e r t a i n ( o p tim a l) l e n g t h , l e v e l o f c o n d i t i o n ­ in g w i l l in c r e a s e to a maximum v a l u e .

A© th e S e-S u i n t e r v a l

i s f u r t h e r le n g th e n e d t h i s l e v e l w i l l d e c r e a s e i n a n eg a­ t i v e l y a c c e l e r a t e d m a n n er, b u t to d i f f e r e n t asym ptote© d e p e n d in g upon when th e 3o ha® c e a s e d to a c t .

T h u s, i f th©

Sc i s e s s e n t i a l l y m omentary (9 ) and d o es n o t te m p o r a lly o v e r­ l a p th© Su ( t r a c e c o n d i t i o n i n g ) , l e v e l o f c o n d i tio n in g w i l l

3 p re su m a b ly f a l l to z e ro a t th e lo n g e r 3e«Su i n t e r r a l e *

If,

on t h e o th e r h an d , th e Sc o v e r la p s th© Su (d e la y e d co n d itio n * * lu g ) t h i s a s y m p to te w i l l p re su m a b ly be a p p r e c i a b l y ab o v e z e ro * ^ Th© e x p e rim e n ta l i n v e s t i g a t i o n s o f th e e f f e c t o f c h a n g in g th© l e n g t h o f th© 8©-Su I n t e r v a l on l e v e l o f c o n d i­ t i o n i n g t h a t h a v e b een r e p o r t e d i n th e l i t e r a t u r e h av e em ployed e i t h e r th e t r a c e o r d e la y e d c o n d i tio n in g te c h n iq u e *

fiv e

o f th e s e ( 1 , 1 0 , 1 2 , 1 4 , 15) h av e em ployed th© fo rm e r te c h n iq u e and two ( 5 , 5) h a v e u t i l i z e d th e d e la y e d p ro c e d u re *

In

g e n e r a l , th e r e s u l t s o f b o th ty p e s o f i n v e s t i g a t i o n s s u g g e s t t h a t t h e r e i s a n o p tim a l S o -S u i n t e r v a l so f a r a s l e v e l o f c o n d i tio n in g i s c o n c e rn e d , and t h a t w ith e i t h e r lo n g e r o r s h o r t e r i n t e r v a l s t h e r e i s a c o r r e s p o n d in g d e c r e a s e i n t h i s le v e l * A ll o f th© f i v e t r a c e - c o n d i t i o n i n g s t u d i e s hav© d e m o n s tra te d t h a t S c-S u i n t e r v a l s s h o r t e r th a n an o p tim a l l e n g t h p ro d u c e l e v e l s o f c o n d i t i o n i n g t h a t a r e lo w e r th a n t h a t p ro d u c e d a t th© o p tim a l i n t e r v a l *

F u rth e rm o re , t h e r e

i s good a g re e m e n t among th© r e s u l t s o f t h e s e i n v e s t i g a t i o n s

1* T hese same r e l a t i o n s h i p s b etw een l e v e l o f c o n d i t i o n i n g and th© 3c~Su I n t e r v a l i n t r a c e a n d d e la y e d c o n d i tio n in g s i t u a t i o n s a r e e x p e c te d on th© b a s i s o f H ull*© somewhat r e v i s e d a s s u m p tio n s . (5 )

s a s t o th® l e n g th o f th® o p tim a l sc**3u i n t e r v a l *

T h ree

s t u d i e s (1 0 , 18* 14) h a v e fo u n d th e o p tim a l l e n g t h to h e v e r y © lo se to $00 m i l l i s e c o n d s , w h ile a f o u r t h (1 ) y i e l d e d 300 m illis e c o n d s *

The f i f t h

i n v e s t i g a t i o n ( 1 5 ) , u s in g a

s m a ll num ber o f s u b j e c t s , r e p o r t e d a 800 m i l l i s e c o n d o p tim a l in te rv a l*

W ith r e s p e c t t o th e e x p e c te d d e c r e a s e i n l e v e l

o f c o n d i tio n in g a s Sc**Su I n t e r v a l s lo n g e r th a n th e o p tim a l a r e em ployed, t h e r e i s a g a in good a g re e m e n t among th e t r a c e * c o n d i tio n in g s t u d i e s * d e m o n stra te d *

I n a i l b u t on® th e d e c r e a s e w as

Wor th e e x c e p tio n (1 ) i t w as fo u n d t h a t i n t e r v a l s

a s lo n g a s 1480 m il lis e c o n d s w ere a s e f f e c t i v e a s th e o p tim a l i n t e r v a l , 300 m illis e c o n d s * I n on® o f th® two d ® la y e d * c o n d itio n in g s t u d i e s , Eimfel® (6) i n v e s t i g a t e d le v ® ! o f c o n d i tio n in g a s a f u n c t i o n o f 3c~8u i n t e r v a l s s h o r t e r th a n th® o p tim a l an d fo u n d t h a t th® g r a d i e n t a p p ro a c h e s t h e maximum i n a n e g a t i v e l y a c c e l e r a t e d mannerIn

th e o t h e r d e la y e d * c o n d itio n in g s tu d y , t h a t o f

K appauf an d S o h lo e b e rg ( 5 ) , a w ide ra n g e o f Sc~8u i n t e r v a l s w as em p lo y ed .

The o p tim a l i n t e r v a l w as r e p o r t e d a s 660

m i l l i s e c o n d s , and th e on® i n t e r v a l t h a t was s h o r t e r th a n 666 m il lis e c o n d s ($33 m il lis e c o n d s ) y i e l d e d a lo w e r l e v e l o f

8* T hese f i n d i n g s a r e a l s o c o n s i s t e n t w ith H u l l 's r e v i s e d p o s t u l a t e s and c o r o lla r ie s ,* ($}*

4

c o n d itio n in g *

a © f o u r lo n g e r i n t e r v a l s p ro d u c e d l e v e l s

t h a t c o u ld be f a i r l y w e ll a p p ro x im a te d b y a n e g a t i v e l y a c c e l e r a t e d decreasing m onotonic f u n c t i o n t h a t r e a c h e d an a sy m p to te a t a b o u t o n e * tb ir d o f th e l e v e l fo u n d a t th e o p tim a l i n t e r v a l {&)*

H ow ever, b e c a u s e t h e r e w ere o n ly two

s u b j e c t s i n ea c h g ro u p and th e s e g ro u p s w ere s u b d iv id e d f o r d i f f e r e n t i a l t r e a t m e n t , th e s e r e s u l t s can be no more th a n s u g g e s tiv e * Purpose of the Experiment The p u rp o s e o f th© p r e s e n t i n v e s t i g a t i o n w as to s tu d y th e r e l a t i o n s h i p between th e l e v e l o f c o n d i tio n in g o f th e e y e l i d re s p o n s e and th e l e n g th o f th e tim e i n t e r v a l betw een th e o n s e t s o f th e c o n d itio n e d and u n c o n d itio n e d s t i m u l i f o r i n t e r v a l s b etw een th e o p tim a l (SCO m il lis e c o n d s ) and 2500 m illis e c o n d s *

5

One h u n d red an d tw e lv e s u b j e c t s w ere u s e d i n th e e x p e rim e n t, o f whom 30 w ere women end SB w ere men.

A ll

w ere member® o f a b e g in n in g b o u rs e i n p s y c h o lo g y a t th e S t a t e U n iv e r s it y o f Io w a.

T h ere was random a s s ig n m e n t o f th e

s u b j e c t s to g r o u p s , e x c e p t t h a t th e p r o p o r ti o n o f women i n th e g ro u p s was k e p t a s n e a r l y e q u a l a s p o s s i b l e *

The Sc was a n i n c r e a s e i n th© l e v e l o f b r i g h t * n e s s o f a m i l k - g l a s s d i s k (d ia m e te r £ .7 5 in c h e s ) from a c o n s ta n t l e v e l o f 0 ,1 9 a p p a r e n t f o o t - c a n d l e s t o a l e v e l o f 0*44 a p p a r e n t f o o t- c a n d le s *

T h is d i s k was c e n te r e d on a

b la c k s q u a re (19*5 in c h e s on a s id e ) l o c a t e d a p p r o x im a te ly 92 in c h e s fro m th e s u b j e c t 1s eye*

I t w as a p p r o x im a te ly 4 .5

in c h e s abo v e th e l e v e l o f th e s u b j e c t 's eye so t h a t th e e y e l i d was c o m p le te ly open when t h e s tim u lu s d is k w as f ix a te d * The Su was a blow from a v i b r a t i n g e le c tr o m a g n e tic hammer d e l i v e r e d t o a p o i n t below t h e r i g h t ©ye o f th e s u b je c t*

T h is hammer w as o o n sta ru c ted b y a t t a c h i n g a l e v e r

arm to th e a rm a tu re o f a 1 2 - v o lt r e l a y .

The r e l a y was

a c t i v a t e d b y 30 v o l t s AC f o r 150 m illis e c o n d s *

6

Two Humi©r*Brora d e c a d e * ty p e e l e c t r o n i c i n t e r v a l * tim e r s (4 ) c o n t r o l l e d th e o n s e t s en d d u r a t i o n s o f th e Sc and th e Su*

One tim e r c o n t r o l l e d th e S c , and th e o t h e r th e S u.

file d u r a t i o n o f th© Su, 150 m illis e c o n d s * was c o n t r o l l e d by th e difference b etw e en th e i n t e r v a l s s e t i n t o th e tim e rs # The r e c o r d in g d e v ic e w as s i m i l a r t o t h a t u s e d by T a y lo r (1 3 )#

B r ie f ly * th e r i g h t e y e l i d was m e c h a n ic a lly

c o n n e c te d to th e i n d i c a t i n g p o i n t e r o f a B u r lin g to n isodeJL 43b F o w # r* le v e l I n d i c a t o r by m m w o f a l i g h t n y lo n th re a d # Th© m e te r w as m ounted on an a d j u s t a b l e h ead band in su c h m way t h a t th e th r e a d from th e p o i n t e r p a s s e d d i r e c t l y to a l i g h t p l a s t i c e x t e n s io n f a s t e n e d to th e u p p e r e y e l i d o f th© su b je c t* © r i g h t eye#

T h is m e te r had been m o d ifie d by rem ove

in g th e e o p p e r- o x id e r e c t i f i e r and w in d in g ® n 'a d d itio n a l c o i l on th e p erm an en t m agnet#

When t h i s c o i l w as e n e r g iz e d

by a 1000-eyel© s i g n a l from an o s c i l l a t o r * v a r i a t i o n s o f a c o r r e s p o n d in g fre q u e n c y w ere in d u c e d i n th e m a g n e tic f i e l d o f th e m eter*

As a co n sequence* a 1 0 0 0 -c y c le v o lta g e m s

d e v e lo p e d a c r o s s th e m e te r c o i l i t s e l f , t h e m a g n itu d e o f t h i s s e c o n d a ry v o lta g e v a r y in g d i r e c t l y w ith th© p o s i t i o n o f th e m e te r c o l l and i t s a t t a c h e d p o in te r #

The o u tp u t o f th e c o i l

w as a m p l i f i e d , r e c t i f i e d , and r e c o r d e d 'g r a p h i c a l l y by means o f a B ru sh e le c tr o m a g n e tic i n k - w r i t i n g o s c illo g r a p h #

Thus

th© in k w r i t e r f o llo w e d th e movements o f th© e y e l i d , e a c h

7 movement b e in g r e c o r d e d a© a d e v i a t i o n i n one d i r e c t i o n fro m a s t r a i g h t lim e* On r e a d in g th e r e c o r d s , a n e y e l i d r e s p o n s e m m c o u n te d i f a d e v i a t i o n g r e a t e r th a n one m i l l i m e t e r o c c u rr e d a t l e a s t 200 m il lis e c o n d a a f t e r th e o n s e t o f th e Sc b u t b e f o r e th # o n s e t o f th e 'S iw

a e e p o n s e e a p p e a r in g b e f o r e 300

m i l l i s e c o n d s a f t e r th e o n s e t o f th®. so w ere n o t in c lu d e d i n th e d a ta a t n ee th e y w ere r e g a r d e d a s o r i g i n a l r e s p o n s e s ( a lp h a o r b e t a ) to th e l i g h t s tim u lu s * The s u b j e c t s w ere c o m fo r ta b ly s e a te d i n an a d j u s t * a b le d e n t i s t 1a c h a i r w h ich w as i n a p a r t i a l l y s o u n d p r o o f e d room*

An e l e c t r i c f a n was u se d to. c i r c u l a t e f i e a i r an d to

s e r v e a s a so u n d * sc re e n *

Th© room w as u n d e r a c o n s ta n t

i l l u m i n a t i o n o f 0*15 f o o t- o a n d le s *

The experim ent© ? re m a in e d

i n a n o th e r room d u r in g th e e x p e rim e n ta l s e s s io n * g o n d itio n in R B r o c e iu r # E ig h ty c o n d i tio n in g t r i a l s w ere g iv e n to th e members o f each e x p e r im e n ta l g ro u p , a l l t r i a l s b e in g a d m in is te r e d d u r in g a s i n g l e e x p e r im e n ta l s e s s io n *

The i n t e r - t r i a l i n t e r ­

v a l s w ere ran d o m ly a s s ig n e d from th e t h r e e v a l u e s , 1 5 , 2 0 , and 2 $ se c o n d s (Mean m 20 s e c o n d s )*

A r e a d y s i g n a l i n th e fo rm

o f a f a i n t b u rste r was p r e s e n te d 2 , 3 , o r 4 se c o n d s b e f o r e th e p re d e te rm in e d tim e f o r th e b e g in n in g o f a t r i a l *

a W inety o f t h e s u b j e c t s if e r e a s s ig n e d ran d o m ly t o th© f o u r e x p e r im e n ta l g ro u p s*

Th© e x p e r im e n ta l tr e a tm e n t o f

th e s e g ro u p s d i f f e r e d o n ly w ith r e s p e c t t o th e l e n g t h o f th e tim e i n t e r n a l b etw e en th e o n s e ts o f th e So and th e su* a © i n t e r v a l s em ployed w ere dO0# 10 0 0 , 1500, and 3&G© milllse c o n d s i n le n g th *

The f i r s t two g ro u p s w ere a s s ig n e d tw e n ty

s u b j e c t s ea ch end th e l a t t e r two tw e n t y - f iv e s u b j e c t s each * The s p e c i a l p ro b lem o f c o r r e c t i n g f o r an a r t i f a c t a r is e © i n c o n n e c tio n w ith an i n v e s t i g a t i o n o f this e x p e rim e n ta l problem *

I n view of th e f a c t t h a t e y e l i d c l o s u r e s o c c u r a t

random i t i s o b v io u s t h a t on© e f f e c t o f c h a n g in g th e l e n g t h o f th e Se*6u i n t e r v a l i s to p r o v id e u n e q u a l opportunities f o r th e o eeurren© * o f random e y e l i d c l o s u r e s d u r in g th e d i f ­ f e r e n t in te rv a ls *

The msm o f th e lo n g e r in te r v a l© would be

e x p e c te d to r e s u l t i n a g r e a t e r t o t a l u m b e r o f .-such random eyelid.blinks#

M o reo v er, t h e r e i s a p o s s i b i l i t y t h a t th e

f r e q u e n c i e s o f th e s e b l i n k s ch an g e d u r in g th e c o n d i tio n in g s e r i e s , and t h a t th e amount o f t h i s change i s u n e q u a l for th e d i f f e r e n t S a-B u i n t e r v a l s *

F o r th e s e r e a s o n s two c o n t r o l

g ro u p s war© in tr o d u c e d i n t o th e e x p e rim e n t* The two c o n t r o l g ro u p s w ere ru n u n d e r c o n d i tio n s t h a t d u p lic a t e d a s f a r a s p o s s i b l e th e c o n d i t i o n s u n d e r w h ich

5* Th© d u r a t i o n o f th© Sc w as 150 m il lis e c o n d s lo n g e r th a n th e s e i n t e r v a l s so a s t o c o m p le te ly o v e r la p th e Su*

9 tits c o n d i tio n in g g ro u p s v e r s run*

One c o n t r o l g ro u p (H « 11}

r e c e i v e d th e Sc f o r SO t r i a l s , and t h e o t h e r (If # I I ) r e c e iv e d th© Su f o r an e q u a l number o f t r i a l s # 3000

mi l l i s e c o n d s , ^

or ^

The Se w as on f o r

Su o c c u rr e d 3000 m il lis e c o n d s

a f t e r th e u s u a l tim e f o r th e o n s e t o f th e Sc ( t * e* S, 3 , o r 4 se c o n d s a f t e r th e r e a d y s ig n a l} #

T h is means t h a t t h e r e

w as an i n t e r v a l o f a t l e a s t f i v e se c o n d s b etw een th e r e a d y s i g n a l and th e S u, a n i n t e r v a l s u f f i c i e n t t o in s u r e a g a i n s t c o n d i tio n in g to th© r e a d y s ig n a l#

A ll o f th e o t h e r e x p e r i ­

m e n ta l c o n d i tio n s w ere th e same a s th o s e f o r th e c o n d itio n in g g roups# During th e few m in u te s when th e s u b j e c t w as becom ing a d a p te d to th e illumination i n th e e x p e rim e n ta l room , the i n s t r u c t i o n s w ere r e a d to him#

T hese i n s t r u c t i o n s ( s e e

Appendix A) w ere d e s ig n e d to in d u c e a n e u t r a l s e t ( n e i t h e r an i n h i b i t o r y n o r a f a e i l i t o r y s e t ) to w ard b lin k in g # P r i o r t o th e e i g h t y c o n d itio n in g t r i a l s , f o u r p r e ­ li m i n a r y t r i a l s w ere run*

The f i r s t t h r e e c o n s i s t e d o f t h e

p r e s e n t a t i o n o f th e Sc a lo n e to b e s u r e t h a t th e s u b j e c t was f o llo w in g i n s t r u c t i o n s and to a s c e r t a i n w h e th e r th e s u b j e c t ’ s

4# A 3OO0 m il lis e c o n d i n t e r v a l was s e l e c t e d so a s to h av e c o n t r o l d a ta f o r a c o n d itio n in g g ro u p r u n u n d e r an Sc-Su i n t e r v a l lo n g e r th a n 0300 m i l l i s e c o n d s , i f th e a d d i t i o n o f such a g ro u p w as found to b e n e c e s s a ry # H ow ever, i t w as n o t fo u n d n e c e s s a r y to add su ch a group#

10 e y e l i d r e s p o n s e w as a l r e a d y c o n d itio n in g t o re s p o n d t o th e s tim u lu s *

The Su { w ith o u t th e s c ) w as g iv e n a s th e f o u r t h

t r i a l i n o r d e r t o s e e w h e th e r th© v i b r a t i n g hammer was p r o p e r ly a d j u s t e d f o r e l i c i t i n g th e u n c o n d itio n e d re s p o n s e * Im m e d ia te ly f o llo w in g t h i s l a s t p r e lim in a r y t r i a l th e s u b je c t* a random b l i n k s w e re c o n tin u o u s ly r e c o r d e d f o r a p e r io d o f f o r t y se co n d s*

Any s u b j e c t who e x h i b i t e d more th a n t h i r t y resp o n se®

d u r in g th e l a s t t h i r t y se c o n d s o f t h i s f o r ty - s e c o n d r e c o r d w as e lim in a te d from th e e x p e rim e n t*

F iv e s u b je c t® w ere

e l im in a te d on th e b a s i s o f t h i s c r i t e r i o n and t h r e e f o r m is u n d e rs ta n d in g th e i n s t r u c t i o n s * A_ su p p le m e n ta ry e x p e rim e n t in w h ich an a i r p u f f w as u se d i n s t e a d o f th© v i b r a t i n g hammer a s th e Su was a l s o run*

T h is w i l l b e d e s c r ib e d i n d e t a i l i n th e H e s u lts and

D is c u s s io n s e c tio n *

BESOMS m > DXSCUSSIGH R m m t m m t w itfe Y ib r a to r a s th e tto o o n d iti om & s tim u lu s Th© a c q u i s i t i o n c u r v e s f o r th© 0 0 0 , 1 0 0 0 , 1 5 0 0 , and 2500 m il lis e c o n d c o n d i tio n in g g ro u p s a r e p r e s e n te d i n F ig u r e 1*

T h ese c u r v e s show th e p e r c e n t o f c o n d itio n e d

r e s p o n s e s i n s u c c e s s iv e b lo c k s o f te n t r i a l s g iv e n b y th© s u b j e c t s i n e a c h g ro u p .

(T h e se p e r c e n t s a r e l i s t e d i n T a b le s

A, B, G, a n d B o f A ppendix B»)

X n sp eeU o n o f F ig u r e 1

r e v e a l s t h a t t h e r e i s a s y s te m a tic u p w a rd * tre n d i n a l l th e c u rv e s #

I t may b e n o te d , h o w ev er, t h a t th© lo n g e r th e So«*

3u i n t e r v a l th e h ig h e r th e p e rc e n t', o f c o n d itio n e d r e s p o n s e s in th e f i r s t b lo c k o f te n t r i a l s .

I f w i l l be r e c a lle d t h a t

t h i s was e x p e c te d s i n c e le n g th e n in g th© Sc*Su i n t e r v a l i n c r e a s e s th e o p p o r tu n ity f o r random e y e l i d c l o s u r e s to o ccu r* I n o r d e r t o c o r r e c t f o r th e d i f f e r e n c e s b etw een th© i n i t i a l p o i n t s i n F ig u re 1 , and th u s p r o v id e more m eaning* f u l i n d i c e s o f d e g re e o f c o n d i t i o n i n g , th© p e r c e n ta g e s ©f c o n d itio n e d r e s p o n s e s i n th e f i r s t b lo c k o f te n t r i a l s w ere s u b t r a c t e d fro m th e s u b s e q u e n t b lo c k s f o r e a c h o f th e g ro u p s* T h is c o r r e c t i o n amount© t o u s in g e a c h s u b je c t a s h i s own c o n tr o l* F ig u r e 2*

The r e s u l t s o f su c h a c o r r e c t i o n a r e shown i n The c u rv e s i n t h i s g ra p h s t i l l show a s y s te m a tic

upw ard t r e n d f o r a i l f o u r experimental c o n d itio n s *

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20 5 0 0 MSC. GROUP 1000 MSC, GROUP 1 5 0 0 MSC. GROUP 2 5 0 0 MSC. GROUP

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1-10

11-20

21-30

31-40 BLOCKS

F ig u re 1

41-50

51 60

61-70

71-80

OF TEN TRIALS

P e r c e n t o f C o n d itio n e d R esp o n ses in S u c c e s s iv e B lo ck s o f Ten T r i a l s f o r th e 500, 1000, 1500, and 2500 m i l l i ­ seco n d groups*

RESPONSES

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40 5 0 0 MSC. GROUP

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1500

MSC. GROUP

2500

MSC. GROUP

20

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1 0 0 0 MSC. GROUP

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__ _

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11-20

21-30

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F ig u r e 2

41-50

51-60

61-70

71-80

OF 10 TRIALS

I n c r e a s e s in P e r c e n t o f C o n d itio n e d R esp o n se s in S u c c e s s iv e B lo ck s o f Ten T r i a l s o v e r th e F i r s t B lock f o r th e 500, 1000, 1500, and 2500 M illis e c o n d Groups*

u 50# m i l l i s e c o n d g ro u p c l e a r l y show a th e g r e a t e s t in c r e a s e i n p e r c e n t o f conditioned re s p o n s e s ,, th e i n c r e a s e s becom ing l e a s a s th e So*Su interval i s le n g th e n e d f o r th e o t h e r g ro u p* The q u e s tio n now a r is e © a s to how much o f th e r i s e i n th e curves o f f i g u r e 2 a c t u a l l y r e p r e s e n t s c o n d i tio n in g an d how much m ig h t m e re ly b© an in c r e a s e that was due p e rh a p s t o o c c u la r f a t i g u e o r o t h e r f a c t o r s an d h en ce w as q u i t e in d e p e n d e n t o f th e c o n d i tio n in g p ro c e d u re # t h a t two c o n t r o l g ro u p s w ere ru n *

I t w i l l be r e c a l l e d

One g ro u p r e c e iv e d e i g h t y

p r e s e n ta tio n © o f th e S c, and th e o t h e r r e c e iv e d an e q u a l num ber o f t r i a l s i n w h ich o n ly th e Su w as p r e s e n te d *

Th© So

w as p r e s e n te d f o r 3000 m il lis e c o n d s to th e fo rm e r g ro u p , and th e l a t t e r r e c e i v e d th e v i b r a t o r 300# m il lis e c o n d s a f t e r th e u s u a l tim e f o r the b e g in n in g o f a t r i a l (2* 3* o r 4 se co n d s f o llo w in g th e r e a d y s i g n a l ) *

The p e r c e n t o f random r e s p o n s e s

made by th e s u b je c t© i n s u c c e s s iv e b lo c k s o f te n t r i a l s d u r in g 800*500, 300*1000, 300*1500, and 300*2500 m il lis e c o n d i n t e r * v a l e was obtained f o r ea c h o f th e two c o n t r o l g ro u p s* T a b le E i n A ppendix B)

(se e

From t h e s e d a ta th e in c r e a s e in p e r*

c e n t o f random e y e l i d r e s p o n s e s i n th e l a s t t h i r t y t r i a l s o v e r t h a t o f th e f i r s t te n t r i a l s w as com puted f o r th e 200*500, 200*1000, 200*1500, and 200*2500 m illis e c o n d i n t e r v a l s o f th e Be an d Su c o n t r o l g ro u p d a ta * \

i n T a b le 1*

The r e s u lt© a r e p r e s e n te d

15

T a b le 1 I n c r e a s e s i n p e r c e n t o f random e y e l i d c l o s u r e s o f l a s t 30 t r i a l s o v e r th e f i r s t 10 t r i a l © d u r in g th e 200*500., 200*1000, 200*1500., and 300*2500 m illis e c o n d i n t e r v a l * f o r th© So and y i b r a t o r c o n t r o l g ro u p s

C o n tro l G roup

200*500

In te rv a l 200*1000

200-1500

200-250