[Dissertation] Uncovering Grammatical Competence in Children with Williams Syndrome

Table of contents :
Acknowledgements
Abstract
Table of Contents
List of Tables
List of Figures
List of Abbreviations
1. Introduction
2. Production of Synthetic Noun-Noun Compounds
3. Production of Relative Clauses
4. Production of Negative Questions
5. Grammaticality Judgment of Negative Polarity Licensing
6. General Discussion
Appendices
References
Curriculum Vitae

Citation preview

BOSTON UNIVERSITY GRADUATE SCHOOL OF ARTS AND SCIENCES

Dissertation.

UNCOVERING GRAMMATICAL COMPETENCE IN CHILDREN WITH WILLIAMS SYNDROME

by

ANDREA ZUKOWSKI M.A., University o f Rochester, 1992 B.A., Wayne State University, 1988

Submitted in partial fulfillment o f the requirements for the degree o f Doctor o f Philosophy 2001

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© Copyright by ANDREA ZUKOWSKI 2001

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Approved by

First Reader ^Sfianley Allen, ^n.D. Assistant Professor of Education Boston University

Second Reader Barbara Landau, Ph.D. Professor of Cognitive Science Johns Hopkins University

Third Reader lary Catherine O’Connor, Ph.D. Associate Professor of Education Boston University

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Acknowledgements

I suspect that the normal way o f writing a dissertation is not the way that I did it. My method was to wait until years after I had finished graduate courses and left town. But it is not entirely my fault that it happened this way. It so happened that upon leaving Boston I found myself managing a research lab in Delaware headed by Barbara Landau. Over the next several years, my feelings about research underwent a gradual change, and at some point it became apparent that I was having fun. I primarily blame Barbara for this, although it can’t have hurt that the entire extended lab family was such a great bunch o f people to work with. I am especially indebted to Barbara for being so supportive when I decided to launch a dissertation project and to Nicole Kurz for so competently shouldering the burden o f running the lab while I was focused on my experiments.

Yet long before I could even pick out Delaware on a blank map o f the U.S., I spent many happy years in Boston, where I took classes on both sides o f the Charles, and benefited from very many friends, peers and teachers. I met Paul Hagstrom in a semantics course at MIT, and neither one o f us could have predicted that he would later end up on my thesis committee. I thank him for agreeing to join it, even while weathering his first year in a tenure-track position at BU. Marco Haverkort was on the faculty at BU for a number o f years, and very many people including m yself benefited from his breadth and depth of knowledge within linguistics and psycholinguistics. I thank him for sharing this with me, and for traveling so far to come to the defense! Shanley Allen arrived at BU after I had already left, and I am sorry to have missed the opportunity to work more closely with her. The Applied Linguistics program is lucky to have her. Jean Berko Gleason gamely agreed to chair my committee at the nth hour, and proved to be an excellent emcee. I owe Cathy O ’Connor very special thanks: for her support, for her friendship, for countless iv

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bagel sandwiches, for her unwavering confidence in me, and for teaching me how to dig for sedge roots. I f I can someday write just half as well as she can, I will consider m yself to be doing fairly well.

Many friends and colleagues from Delaware helped m e to run m y experiments in a frenzied and very small number o f months. For this, a very big thank you to Nicole Kurz, Colin Phillips, Jill Siegfried, Barney Pagani, Danny Dilks, Heather Jordan, and Barbara Landau. Colin Phillips offered extremely valuable and detailed advice on the first draft o f this thesis, and made the copy that my committee received a far more readable piece o f work. His own standards for academic work have benefitted this thesis immeasurably. I also received some much-needed advice relevant to m y NPI study from a number o f semantics-saavy friends. Thank you to Satoshi Tomioka, M artin Hackl, and Elena Guerzoni. Annabel Greenhill and Anna Do played an extremely valuable role in helping me to get paperwork signed sealed and delivered, even though I was 400 miles from Boston, and I am very grateful to them for their legwork.

Many people in Boston made my time there enjoyable and interesting. I would especially like to thank m y friends from my earliest days at BU: AJeka Blackwell, Mary Bodwell, Dalia Cahana-Amitay, Susan McEwen, Bhuvana Narasimhan, Andy Stringfellow, Saskia Stoessel, and Linda Taylor.

Delaware could not have been more fun, and I will miss not just one, but two lab groups (Barbara’s and Colin’s). Besides Barbara and Colin themselves, I thank very many folks whose discussions o f matters both light and deep will be missed: Nicole Kurz, Barney Pagani, Dave Schwartz, Ed Munnich, Meesook Kim, Heather Jordan, Danny Dilks, Jim v

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Hoffman, John Whalen, Dave Schneider, Baris Kabak, Nina Kazanina, Evniki Edgar, Jason Lilly, Kaia Wong, Satoshi Tomioka, Gaby Hermon, and Peter Cole.

Lixa was my constant furry companion (and research assistant) during many long hours o f writing, and she deserves my thanks for making the wee hours more bearable (and for giving m e an excuse to sometimes put my laptop aside).

O f course my greatest thanks go to Colin Phillips. He was an unbidden accomplice at every stage o f this project, and I know that it would be a humbler achievement if not for his influence. I could list countless moments during the planning, designing, testing, and writing o f this thesis when I was ready to give up, and at every one o f those moments, it was Colin’s encouragement alone that kept me going. I cannot thank him enough for always being there.

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UNCOVERING GRAMMATICAL COMPETENCE IN CHILDREN WITH WILLIAMS SYNDROME (Order No.

)

ANDREA ZUKOWSKI Boston University Graduate School o f Arts and Sciences, 2001 Major Professor: Shanley Allen, Assistant Professor o f Education ABSTRACT Williams Syndrome (WS) is a genetic disorder that results in widespread cognitive impairments without the accompanying severe language deficits sometimes observed in other cognitive disorders (e.g. Down Syndrome). The WS cognitive profile is often invoked as support for language modularity. However, recent work has challenged the significance o f WS in the modularity debate because WS language does not exceed the language o f unimpaired children o f similar mental age, and because some evidence suggests that WS language is anomalous and therefore cannot be used to support claims about the nature of unimpaired brains. But some past evidence has relied on standardized tests that m ay confound language abilities and cognitive abilities, and such tests reveal little about the nature o f the underlying language system.

This thesis explores what the WS language profile its e lf reveals about the level o f grammatical sophistication that can be achieved in the context o f an impaired cognitive system. Four studies examined the nature o f the grammatical system in WS. Twelve WS children (age 8—16) and twelve unimpaired children o f similar mental age (4—7 years) were tested. Three studies used an elicited production technique to encourage production o f 3 structures: noun-noun compounds, embedded relative clauses, and affirmative and negative questions. A fourth study used a grammaticality judgment technique to assess vii

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sensitivity to licit and illicit uses o f the expressions any and some.

The studies yielded 3 findings. First, the linguistic knowledge reflected in the WS iresults was highly sophisticated, and comparable to that o f the unimpaired controls. Se=cond, both groups experienced difficulty with some structures, and this difficulty was often exaggerated for the WS group. Finally, the two groups were highly similar in the o*verall pattern o f ease vs. difficulty and in their overt errors.

These findings suggest that WS syntactic development is driven by normal mechamisms o f language acquisition, and the gram m atical system is ultimately m uch m o re sophisticated than that observed in other cognitive disorders with comparable retardation. Thus, WS is indeed highly relevant to the modularity debate. The findings also su g g est that imperfect levels o f language performance in WS m ay reflect an exaggerated influence o f normal processing factors.

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Table of Contents Table of Contents_____________________________________________________________ix List of Tables________________________________________________________________ xii List of Figures............................................................................................__ ... ........................ xv List of Abbreviations

--------------------------------------

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1. Introduction................................................................................................................................... 1 1.1 Overview....

__________________________________________________________1

1.2 Williams Syndrome and Modularity-----------------------------------------------------------------3 13 Williams Syndrome Genotype and Phenotype--------------------------------------------------- 12 1.4 Review of Cognitive Abilities and Disabilities in Williams Syndrome______________ 13 1.4.1 Full Scale IQ....................................................................................................................................................13 1.4.2 Spatial Cognition D eficits.............................................................................................................................14 1.4.3 Piagetian Conservation Tasks...................................................................................................................... 17 1.4.4 Mathematics and Number Concepts........................................................................................................... 18 1.4.5 Folkbiology Concepts................................................................................................................................... 19 1.4.6 Auditory Short Term Memory.................................................................................................................... 20 1.4.7 Face Processing..............................................................................................................................................21 1.4.8 Theory o f Mind...............................................................................................................................................23

1.5 Review and Discussion of Language Abilities and Disabilities in Williams Syndrome .........................................................................................................................................................24 1.5.1 Production o f Complex Sentence Structures............................................................................................24 1.5.2 Language is Delayed in Williams Syndrome...........................................................................................27 1.5.3 Performance on Comprehension T ests......................................................................................................28 1.5 4 Elicited Production may Reveal Competence Masked by Cognitively Difficult Comprehension T ests...........................................................................................................................................................................35 1.5.5 Morphosyntactic Operations........................................................................................................................38 1.5.6 Lexical Anomalies......................................................................................................................................... 41 1.5.7 Sensitivity to Syntactic Violations: Putting This to Good U se.............................................................44

1.6 Overview of Four New Studies.............................................................................................. 47 2. Production of Synthetic Noun-Noun C om pounds...........................................................49 2.1 Background and Motivation.................................................................................................. 49 2.2 Subjects.....................................................................................................................................50 2 3 Method......................................................................................................................................53 2.3.1 Materials........................................................ 53 2.3.2 Procedure........................................................................................................................................................ 55

2.4 Results.......................................................................................................................................57 2.4.1 Plural Responses............................................................................................................................................ 57 2.4.2 Compound Responses...................................................................................................................................60 2.4.3. Summarizing the Results............................................................................................................................. 65

2.5 Discussion................................................................................................................................. 65

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2.5. LWhat kind o f linguistic competence has been revealed?.......................................................................65 2.5.2 Comparison with other disordered groups............................................................................................... 68

3. Production o f Relative C lau ses............................................................................................ 75 3.1 Background and Motivation--------------------------

75

3.2 Subjects_________________________________________________________________ 78 3 3 Method__________________________________________________________________79 3.3.1 Materials........................................................................................................................................................ 79 3.3.2 Procedure....................................................................................................................................................... 82

3.4 Results_______________________ 3.4.1 3.4.2 3.4.3 3.4.4

85

Success o f the M ethodology...................................................................................................................... 85 Overview o f Results.....................................................................................................................................85 Presence and Grammatical Quality o f Relative Clauses........................................................................ 88 Relative Difficulty o f Different Relative Clauses...................................................................................97

108

3.5 Discussion...............................................

3.5.1 A Method for Reliable Elicitation o f Embedded Relative Clauses....................................................108 3.5.2 What kind o f linguistic competence has been revealed?..................................................................... 109 3.5.3 Questions Raised by the Results.............................................................................................................. 110 3.5.4 Conclusion....................................................................................................................................................121

4. Production o f Negative Q uestions..................................................................................... 123 4.1 Background and Motivation.....................

123

4.2 Subjects.................................................................................................................................. 126 4.3 Method................................................................................................................................... 126 4.3.1 Materials.......................................................................................................................................................127 4.3.2 Procedure......................................................................................................................................................131

4.4 Results.................................................................................................................................... 132 4.4.1 4.4.2 4.4.3 4.4.4

Success o f the Methodology.....................................................................................................................133 Overview o f the Results............................................................................................................................ 134 Group Data....................................................................................................................................................136 Individual Data............................................................................................................................................138

4.5 Summarizing the Results.................................................................................................... 146 4.6 Discussion.............................................................................................................................. 147 5. Grammaticality Judgm ent o f Negative Polarity Licensing....................................... 156 5.1 Background and Motivation............................................................................................... 156 5.2 Subjects.................................................................................................................................. 164 5.3 Method................................................................................................................................... 166 5.3.1 Materials.......................................................................................................................................................167 5.3.2 Procedure......................................................................................................................................................168

5.4 Results.................................................................................................................................... 169 5.5 Summarizing the Results--------------------------------------------------------------------------- 185 5.6 Discussion.............................................................................................................................. 186

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6. G eneral D iscussion..................................................................... —...................................... 197 6.1 Overarching Results--------------------------------------------------------------------------------- 197 6.2 Summary of the Collective Evidence-------------------------------------------------------------- 198 6.2.1 Language similarities between WS and control children: Areas w here both groups were proficient.............................................................................................................. 199 6.2.2 Language similarities between WS and control children: Areas w here both groups experienced difficulty............................................................................................................... 202 6.2.3 Language similarities between WS and control children: Overt errors produced by both groups ................................................................................................................................ 203 6.2.4 Language differences between WS and control children................... 205

6 3 Down Syndrome Language: A Comparison------------------------

207

6.4 Williams Syndrome and Modularity Revisited.-------------------

209

6.4.1 Do cognitive impairments predict language impairments?............... 209 6.4.2 Since WS language is so good, what prevents it from getting any better?......................................210 6.4.3 Is language or language acquisition abnormal in W S?...................... 218

6.5 Lessons for Research into WS language----------------------------

221

Appendices............................................................................................ - ....................................... 223 Appendix A. Individual Scores forNoun-noun Compounding Study ................................................224 Appendix B. Relative Clause Target Structures.............................................................................................. 231 Appendix C. Sample o f Relative Clause Stimuli for all 4 Manipulations o f 1 Base Picture................. 233 Appendix D. All Relative Clause Responses from One WS Adolescent (IQ = 4 0 ) ................................ 234 Appendix E. “Other” Responses in Relative Clause Study........................ _.................................................236 Appendix F. Negative Question Target Structures........................................ 238 Appendix G. Grammaticality Test: Sentences Presented.......................... - .................................................239

References..............................................................................................

240

Curriculum Vitae...................................................................................

248

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List o f Tables Table 1. Error rates on a Language Comprehension Test: WS vs. The Elderly...............31 Table 2. Ages and Test Scores o f WS Participants................................................................52 Table 3. Ages and Test Scores o f Typically-developing Controls.......................................53 Table 4. Mean Standard Scores for the Two G roups........................................................... 53 Table 5. Stimuli Used in Noun-noun Compounding S tudy................................................. 55 Table 6. Examples of Possible Responses to the Plural Prompt.........................................58 Table 7. First Response to the Plural Prompt: Mean Percent Production o f Different Form s................................................................................................................................. 58 Table 8. Final Response to the Plural Prompt for Irregular Nouns: Mean Percent Production o f Different Forms.........................................................................................59 Table 9. Examples of Possible Compound Responses.......................................................... 61 Table 10. Compound Responses: Mean Percent o f Regular Plural, Irregular Plural, and Singular Forms Produced Inside Com pound................................................................. 62 Table 11. Compound Responses from Normal A dults......................................................... 64 Table 12. Regular Plurals Produced inside Compounds in the X-eater Paradigm .............71 Table 13. Mean Ages and Test Scores for the Two Groups in the Relative Clause Study .............................................................................................................................................79 Table 14. Descriptions of 16 Base Pictures in Relative Clause Study................................. 80 Table 15. Total Incidence o f Basic Response Types by Group in Relative Clause Study 86 Table 16. Incidence of Any SG relatives by Individual for all 48 SG Opportunities........89 Table 17. Incidence of Right-branching and Center-embedded SG relatives by Individual in all 48 SG Opportunities............................................................................................... 90 Table 18. Incidence of Any OG relatives by Individual for all 48 OG Opportunities.......91 Table 19. Incidence of Right-branching and Center-embedded OG relatives by Individual in all 48 OG Opportunities............................................................................................... 92 Table 20. Attested examples o f different structures in elicited speech: W S ......................94 Table 21. Attested examples o f different structures in elicited speech: Controls...............94 xii

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Table 22. Average Number o f Target Gap Relatives Produced in Target Embedded Position for the 64 Full Sentence Opportunities...........................................................99 Table 23. Incidence o f Semantically Appropriate SG Relatives Produced in OG Trials by G roup............................................................................................................................... 101 Table 24. Total Incidence o f Different SG Responses in All 48 OG Opportunities by G roup............................................................................................................................... 103 Table 25. Rates o f Mapping Errors in OG Trials as a Function o f Embedding Condition ...........................................................................................................................................105 Table 26. Trial-by-trial Rates o f Mapping Errors for OG Conditions............................... 107 Table 27. Sample Target Questions in Negative Question Study...................................... 127 Table 28. Sample Protocols in Negative Question Study.................................................. 128 Table 29. All Questions: Average Percentage o f Various Structures Produced by Both Groups.............................................................................................................................. 135 Table 30. Affirmative Yes/No Questions: Controls............................................................ 139 Table 31. Affirmative Yes/No Questions: W S .................................................................... 139 Table 32. Affirmative Wh-Questions: C ontrols..................................................................140 Table 33. Affirmative Wh-Questions: W S...........................................................................141 Table 34. Negative Wh-Questions: Controls....................................................................... 142 Table 35. Negative Wh-Questions: W S ............................................................................... 142 Table 36. Object vs. Adjunct Negative Questions.............................................................. 145 Table 37. Negative Why vs. Where/When Questions: Controls........................................ 146 Table 38. Negative Why vs. Where/When Questions: W S ................................................. 147 Table 39. Ages and Raw Test Scores o f WS Participants in NPI Study............................166 Table 40. Ages and Raw Test Scores o f Non-disordered Controls in NPI S tu d y ............167 Table 41. Mean Ages and Test Scores for the Two Groups in NPI Study....................... 167 Table 42. Experimental Conditions for NPI Judgment Task.............................................. 168 Table 43. Average Sensitivity Score for All Conditions o f the NPI Task........................ 173 Table 44. Language competence observed in WS and non-disordered children............. 201 xiii

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Table 45. Language difficulties observed in WS and non-disordered children............203 Table 46. Overt errors observed in WS and non-disordered children........................... 205 Table 47. Differences between the Language o f WS and Non-disordered Children

206

Table 48. First Response to Plural Prompt for Known Objects with Regular Plurals: WS ........................................................................................................................................ 225 Table 49. First Response to Plural Prompt for Known Objects with Regular Plurals: Controls.........................................................................................................................226 Table 50. First Response to Plural Prompt for Unknown Objects: W S......................... 227 Table 51. First Response to Plural Prompt for Unknown Objects: Controls.................227 Table 52. First Response to Plural Prompt for Known Objects with Irregular Plurals: W S .................................................................................................................................228 Table 53. First Response to Plural Prompt for Known Objects with Irregular Plurals: Controls......................................................................................................................... 228 Table 54. Compound Responses for Known Objects with Regular Plurals: W S

230

Table 55. Compound Responses for Known Objects with Regular Plurals: Controls ... 230 Table 56. Compound Responses for Unknown Objects: W S...........................................232 Table 57. Compound Responses for Unknown Objects: Controls..................................232 Table 58. Compound Responses for Known Objects with Irregular Plurals: WS

233

Table 59. Compound Responses for Known Objects with Irregular Plurals: Controls.. 234 Table 60. Examples o f ‘Other’ Responses in Relative Clause Study............................. 240 Table 61. Percent o f All ‘Other’ Responses in Relative Clause Study Accounted for by Different C ategories.................................................................................................... 241

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List o f Figures Figure 1. Sample Item from Bihrle et al., 1989...................................................................... 14 Figure 2. Difficult TROG E xam ple.........................................................................................33 Figure 3. Sample stimulus that elicited mapping errors in relative clause study.............102 Figure 4. Grammatical Fillers vs. Ungrammatical Fillers................................................... 172 Figure 5: Average Sensitivity Score for All Conditions o f the NPI Task......................... 174 Figure 6. Negative vs. Positive + A n y ....................................................................................175 Figure 7. Affirmative vs. Negative + Som e...........................................................................178 Figure 8. Affirmative + Some vs. A n y ....................................................................................179 Figure 9. First vs. second argument o f Every + A n y ............................................................ 181 Figure 10. Only vs. Every -FA n y.............................................................................................183 Figure 11. Before vs. After + A n y .......................................................................................... 185

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List o f Abbreviations avg cont DAS DE DS ERP FISH IPSyn IQ KBIT MA msec OG SD SG SLI TROG WAIS

wise WS

average control Differential Abilities Scale downward entailing Down Syndrome event-related potential florescence in situ hybridization Index o f Productive Syntax Intelligence Quotient Kaufman B rief Intelligence Test mental age millisecond object gap (relative clause) standard deviation subject gap (relative clause) Specific Language Impairment Test for Reception o f Grammar Wechsler Adult Intellligence Scale Wechsler Intelligence Scale for Children Williams Syndrome

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1. Introduction 1.1 Overview W illiams Syndrome (henceforth, WS) is a rare neurodevelopmental disorder usually caused by the spontaneous deletion o f a short sequence o f contiguous genes on chromosome 7. This genetic disruption results in a large variety o f physical and cognitive problems, and WS individuals typically test at mild to moderate degrees o f mental retardation. Great attention has been focused on WS since initial reports by Bellugi and colleagues (Bellugi, Marks, Bihrle, and Sabo, 1988) of a dramatic sparing o f language abilities in conjunction with severe deficits in other aspects o f cognition (visuo-spatial construction, Piagetian conservation, number ability). If this characterization o f selective sparing o f language is accurate, then WS provides strong evidence for the modularity o f language.

Since the initial reports, much debate has ensued over both the facts about WS language and their interpretation. Happily, this debate has fueled a flurry o f investigations into WS language abilities. However, the collective results have now left the picture rather murky. Some evidence suggests that although language abilities in WS are clearly superior to visuo-spatial construction abilities in this population, they are at best m erely commensurate with overall mental age, and at worst, not only worse than mental age, but qualitatively different, reflecting properties that are not seen at all in normal language development (Karmiloff-Smith, Grant, Berthoud, Davies, Howlin and Udwin, 1997; Mervis, Morris, Bertrand, and Robinson, 1999; Volterra, Capirci, Pezzini, Sabbadini, and Vicari, 1996; Klein, 1995; Greer, Brown, Pai, Chodry, and Klein, 1997). Other evidence suggests that language is indeed selectively spared in WS (Bellugi, Bihrle, Neville, Doherty, and Jemigan, 1992; Rossen, Klima, Bellugi, Bihrle, and Jones, 1996; Clahsen

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and Almazan, 1998).

I argue that many important implications o f the WS cognitive profile for questions o f language modularity have yet to be explored, and that what is needed is an in-depth understanding of the grammatical system that develops in WS. Such an understanding will offer evidence relevant to three questions that bear on m odularity issues: How closely does WS language manage to approximate unim paired language, despite m oderate mental retardation? Do WS language abilities outstrip general cognitive abilities when the cognitively-matched comparison group is non-disordered? And is WS language development guided by the same m echanism s a s norm al language development?

In this thesis I report four studies examining a wide range o f language abilities in a group o f 12 WS children and a group o f non-disordered children o f the sam e mental age. One study directly addresses past reported problem areas in WS language— relative clauses embedded in full sentences. A second study examines sensitivity to a morphological constraint on the production o f noun-noun compounds— a constraint which renders compounds like rats-eater ill-formed, but forms like mice-eater well-formed. The other two studies look at new aspects o f WS language—negative questions and sensitivity to licensing contexts for negative polarity items. These final two language areas were chosen because it is known that some non-adult patterns are exhibited by non-disordered children who are o f the same mental age as our WS group. In both o f these language domains, however, the error pattern is highly specific to certain contexts, and children who make these errors simultaneously perform extremely well in minim ally contrasting contexts.

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The combined set o f studies provides ample opportunity for the WS group to display (or to fail to display) sophisticated linguistic knowledge in a variety o f areas, and to surpass (or to fail to surpass) unimpaired mental-age-matched children in these language areas. Furthermore, since unimpaired children display a profile o f specific types o f errors in highly specific contexts, and they fail to display similar errors in closely related contexts, we can see whether WS children track these patterns. Similar profiles would suggest similar acquisition mechanisms. 1.2 Williams Syndrome and Modularity The WS cognitive profile is often invoked as evidence in several m ajor debates concerning language. The first debate asks whether language is a modular cognitive system. The concept o f a language module has been understood in different ways by different theorists (Fodor 1983; Moscovitch and Umilta, 1990), but among linguists the concept is commonly understood as a system o f knowledge that is specialized for language (i.e. “dom ain specific”), and that therefore operates to some degree independently o f both general cognitive systems and other specialized systems (i.e. it is, to some degree, “encapsulated”). For example, Chomsky (1988) discusses both o f these features in a comparison o f language and human vision: The language faculty does not include the rigidity principle or the principles that govern apparent motion, and the visual faculty does not include the principles o f binding theory, case theory, structure dependence, and so on. The two systems operate in quite different ways, not surprisingly. What is known about other cognitive domains suggests that the same is true elsewhere, though so little is known that one cannot be sure. It seems that the mind is modular, to use a technical term, consisting o f separate systems with their own properties. O f course the systems interact; w e can describe what w e see, hear, smell, taste, imagine, etc.— sometimes. There are thus central systems o f some kind, but about these little is understood, (p. 161)

This notion of language modularity is the one that I wil intend henceforward: a cognitive system that involves representations and principles that are specific to human language,

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and that do not resemble the kinds o f representations and principles that are used by any other human cognitive systems.

The second debate asks whether the capacity for language is innate (i.e. genetically specified). More specifically, the debate concerns whether a system specialized for acquiring language is innately specified. If so, this leads to a number o f predictions about language breakdown in developmental disorders, as exemplified in the following excerpt from Pinker (1994). I f language is an instinct, it should have an identifiable seat in the brain, and perhaps even a special set o f genes that help wire it into place. Disrupt these genes or neurons, and language should suffer while the other parts o f intelligence carry on; spare them in an otherwise damaged brain, and you should have a retarded individual with intact language, a linguistic idiot savant. If on the other hand, language is just the exercise o f human smarts, we might expect that injuries and impairments would make people stupider across the board, including their language, (p. 45)

Pinker seems to propose these as mutually exclusive possibilities: either there will be highly specific sparing or damage to the language system—if language is an instinct—or else language deficits will be commensurate with other cognitive deficits—if language is a by-product o f human cognition. However, I think it is important to point out that across-the-board impairments may sometimes occur, regardless o f the truth about the innateness and/or modularity o f language. To put it simplistically, human genes do not acquire language— hu m an brains do. But genes have to first build a brain that is capable o f this achievement. Thus, a particular genetic disruption may affect the building o f a brain in a pervasive way, or in a more restricted way. So even if—under normal circumstances—the capacity for language is expressed as a neurally dedicated language system at birth, a genetic disruption may suffice to build a brain that lacks this dedicated system. Roughly the same argument was made by Moscovitch and Umilta (1990) with regard to loss o f function in dementia, as expressed in this excerpt:

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5 A problem with using residual capacities (sparing o f function) in the face o f generalized intellectual loss as an index for informational encapsulation is that the conditions that gave rise to the general intellectual deficit are likely also to affect each particular module. Even if some modules are not affected, the patient’s inability to follow instructions may make it impossible to evaluate the state o f the modules. For these reasons, failure to find that a particular modular function is spared, in the face o f general intellectual loss, does not constitute evidence against informational encapsulation. Only positive evidence counts.” (p. 8).

On the other hand, the existence o f the other pattern that Pinker discusses— specific sparing or damage to the language system, particularly in a neurodevelopm ental disorder—would strongly support the idea o f language modularity, in the sense described above. Such a pattern would be difficult to reconcile with the view that a specialized language system is a by-product o f general human cognition or o f general purpose brain mechanisms. This is acknowledged by Karmiloff-Smith (1998), who represents one theoretical position o f the “general mechanisms” type. Karmiloff-Smith argues that in the normal course o f events adults do achieve language modularity, but that a dedicated language system is the product o f the interaction between language input and innately specified “domain relevant” mechanisms (as opposed to domain specific mechanisms). For example, she suggests that there might be mechanisms that are innately specialized for processing sequential input (by virtue o f having the architectural feature o f a feedback loop), but that “with time such a mechanism would become progressively dedicated to processing, say, sequentially presented linguistic input” (1998). According to this view, damage to a still-developing brain is expected to have widespread (inter-domain) consequences: In this approach the deletion, reduplication or mispositioning o f genes will be expected to subtly change the course o f developmental pathways, with stronger effects on some outcomes and weaker effects on others. A totally specific disorder will, ex hypothesis, be extremely unlikely, thereby changing the focus o f research in pathology. Rather than solely aiming to identify a damaged module at the cognitive level, researchers are encouraged to seek more subtle effects beyond the seemingly unique one, as w ell as to question whether successful behaviour (the presumed ‘intact’ part o f the brain) is reached by the same processes as in normal development (p. 390)

Initial reports from Bellugi and colleagues about the strength o f language abilities in WS

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compared to their overall cognitive impairments im m ediately drew the attention o f investigators engaged in these fundamental debates. Bellugi, Marks, Bihrle, and Sabo (1988) described three 11—16 year old WS children who had IQ s around 50, who had the visuospatial construction skills o f 5-year-old children, a n d who failed Piagetian conservation tasks that are normally mastered by age 7. But the authors reported that their expressive language was “complex in terms o f morphologicatl and syntactic structures including full passives, embedded relative clauses, a range o f conditionals and multiple embeddings” (p. 183). Here are some excerpts o f WS speech reported by Bellugi et al. (1988): “When I got up the next morning, I talked but I couldn’t say anythfing so my mom had to rush me to the hospital” (p. 183) “There is a huge magnetic machine. It took a picture inside the bratin. You could talk but not move your head because that would ruin the whole thing and thiey would have to start all over again. After it’s all done they show you your brain on a com puter and they see how large it is. And the machine on the other side o f the room tak es pictures from the computer. They can take pictures instantly. Oh, and it was very exciting!” (p. 183) “After it stopped hurting, I was told that I could go to school again ^and do whatever I feel like doing. I f it got really infected they would have taken my toe offf. They had to give me ether so that I would not feel the pain” (p. 184)

A large amount o f research into WS language and cognition h a s now been conducted, but there is no agreement as yet about the implications o f the results for questions about modularity. W hat everyone does agree on is that WS langmage is impressive for a retarded population, but it is by no means entirely intact. H ow ever, m uch debate has revolved around two questions: is WS language at least selectively spared relative to the rest o f cognition, and does the pattern o f linguistic strengths and weakness reflect theoretically interesting divisions within language?

By selective sparing what is usually meant is that language perform ance is better than one would expect on the basis o f overall mental age (henceforth: MA). The selective

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sparing question has proven recalcitrant, in part because the results are confusing. For example, the answer depends on the choice o f MA-matched comparison group, and on the age o f the WS individuals. W hen the control group with similar MA is also retarded (e.g. Down syndrome children), WS language does surpass MA expectations (Bellugi et al., 1988; Bellugi, Lichtenberger, Jones, Lai, & St. George., 2000). However, when the control group with similar MA is non-disordered, it typically does not (e.g. KarmiloffSmith et al., 1997; Volterra et al., 1996, Capirci, Sabbadini, and V olterra, 1996). Moreover, it has been argued that language does not surpass non-linguistic cognitive abilities in early childhood, but that it does in late childhood and beyond (Jarrold, Baddeley, and Hewes, 1998).

But even abstracting away from this confusing pattern o f results, the question o f whether WS language is selectively spared is extremely difficult to answer for another important reason. There is simply no agreed-upon model o f what an intact or spared language system would look like if it was embedded in a cognitively impaired brain. As yet we know relatively little about how unim paired language systems interact with the processing systems subserving production and comprehension, and we know even less about how these processing systems normally develop. Thus, the answer to the selective sparing question for WS language is not simply a matter o f matching the results o f language tests to a model that we already understand and agree upon.

The other debate about WS language concerns the nature o f their language profile. Short o f completely intact language, one could imagine many kinds o f language profiles that would be interesting and informative in their own right. Several researchers believe that the pattern o f strength and weakness exhibited in WS reflects the internal modularity o f

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the language system. For example, Clahsen and Almazan (1998, in press) believe that the pattern reflects an intact computational system, but an impairment in the lexical system and/or its access mechanisms. However other researchers believe that the pattern o f breakdown in WS language is much noisier than this, and that even apparently good performance in some tasks masks abnormality in the language domain (Karmiloff-Smith et al, 1997, Capirci et al., 1996).

These two debates— the selective sparing debate and the language profile debate—both speak to modularity issues. Selective sparing o f language (just like completely intact language) would reflect an independence o f language from cognition, while certain language profiles would provide evidence for particular independent components within the language system. Levy (1996) refers to these two modularity issues as “Big Modularity” and “little modularity”. I adopt these terms here.

In m y opinion, the selective sparing debate has overshadowed some o f the most interesting implications o f WS language for questions about Big Modularity. The fundamentally remarkable thing about WS language, which has been highlighted in the work o f Bellugi and colleagues for at least a dozen years, is how good it gets by comparison to the level o f language usually attained in Down Syndrome. The two disorders result in comparable degrees o f overall cognitive impairment, but language ends up miles apart. The level o f language sophistication described in the quote above from Bellugi is quite typical of WS individuals. By contrast, consider an excerpt from Rondal (1995) that summarizes the ultimate level o f expressive language achievement attained by most DS adults (the group described here were French): ...the spontaneous combinatorial language o f DS individuals remains largely telegraphic (in the sense o f R. Brown, 1973). It is characterized by a reduced use o f function words

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9 (articles, prepositions, auxiliaries, copulas, pronouns, conjunctions). The lack o f appropriate feature marking on pronouns and anaphors may render the referring expression opaque to the nonfamiliar interlocutor. Word ordering, however, is usually correct...Such a state o f affairs largely persists into the adult years as indicated by analysis o f conversational data gathered by Rondal and Lambert (1983) with DS adults living in the community...Less than half o f the utterances recorded in that study were grammatical sentences. When the verb was expressed, it was properly inflected only approximately half o f the time. The tense most often used was the present indicative, even in narrative contexts clearly referring to completed past events. There was less than one article per utterance and slightly over one inflection marking gender or number on the noun phrase in two utterances, (p. 9).

Anyone with an interest in the nature o f the language faculty and the nature o f mechanisms o f language acquisition should wonder how it is that this discrepancy is possible. The relevance o f this discrepancy for the question o f Big M odularity is obvious— i f one cannot predict ultimate language success on the basis o f overall intelligence or specific non-linguistic cognitive abilities, then language m ust be a modular system to some degree. And the greater the discrepancy, the stronger the evidence for language modularity.

Since the focus o f much past research has addressed the selective impairment question, there has been little reason for researchers to try to characterize the nature o f the linguistic abilities that have been attested in WS (Clahsen and Almazan are a notable exception). This is unfortunate because it means that the implications o f WS language for questions concerning little modularity have also been neglected.

So what is called for is a broad but detailed linguistic profile of WS language— a goal that is shared by Clahsen and Almazan (in press). We currently have an incomplete picture o f this profile. This is due to a number o f things. First, linguistic knowledge is vast, and only a small fraction o f language abilities have been examined in WS (those that have are discussed in section 1.5). Second, some researchers have warned that apparently good language performance in WS may m ask underlying abnorm ality

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(Karmiloff-Smith et al., 1997; Volterra et al, 1994). Third, different assessment methods have sometimes provided contradictory answers. F or example, WS individuals are reported to produce some grammatically correct complex structures (relative clauses) that they nevertheless have difficulty comprehending in standardized tests (Karmiloff-Smith et al., 1997; Mervis et al. 1999). Perhaps this difference reflects interesting differences in the systems responsible for comprehension vs. production in WS, but perhaps it merely reflects test confounds. W e just cannot tell from the results that are currently available.

W hat would be really useful to know is whether WS individuals are lacking knowledge o f particular structures, whether they fail to follow certain constraints, whether they make mistakes despite evidence that they possess the requisite knowledge and constraints, and so on. Researchers m ay not be able to definitively agree on whether WS language is “selectively spared”, but it would be extremely interesting to know how far people with WS come to approxim ating non-disordered language competence, since they may represent one extreme end o f a continuum o f possible language outcomes for cognitively impaired groups. Furthermore, it would be extremely interesting to know whether the pattern o f ease and difficulty in their linguistic profile reflects theoretically interesting distinctions.

My goal in the studies that I report here is to broaden the range o f language abilities that have been exam ined in WS, and to uncover the nature o f both their grammatical competence and their grammatical problems.

I begin this program o f research with four studies examining a variety o f language abilities in a group o f 12 WS children and adolescents (age 8—16). Their performance is

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compared to unimpaired 4—7-year-old children who have the same MA as the WS group. At this age, unimpaired children are already in control o f extremely impressive language abilities, but they still make characteristic errors in very specific environments. Thus, the tests will reveal not only whether the WS children perform well or poorly, they will also reveal whether WS language patterns match those o f children with non-disordered language. I primarily use the technique o f elicited production, which involves placing children in communicative situations that uniquely call for the production o f structures that the experimenter is interested in (in the ideal case). This technique has proven successful in demonstrating competence in particular language domains in young unimpaired children who perform worse in these domains when tested by other means

(m any examples o f this are summarized in Crain and Thornton, 1998). Elicited production offers another important benefit as well— it allows the experimenter to examine knowledge o f structures that tend to be rare in spontaneous speech. For these and other reasons discussed in 1.5.4, I believe that the elicited production technique is particularly well-suited to assessing grammatical abilities in WS individuals.

With m ore informative tests, with potential confounds removed, and with results from an ever-broadening range o f linguistic abilities on the table, w e can determine whether there are commonalities in the range o f language abilities that WS individuals do well (and poorly) on, and we can see just how close WS language can come to approximating nondisordered language. The full picture o f language abilities and disabilities in WS, along with knowledge o f WS strengths and weaknesses in other cognitive domains may inform us about the architecture o f the language system, and/or the performance systems which subserve it.

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A detailed review and discussion o f past work on WS language will be provided in section 1.5, and this will motivate the four language studies that follow. B ut before turning to WS language, I review some background information on the WS genotype and clinical phenotype, and on non-linguistic cognitive abilities and disabilities observed in the disorder.

1 3 Williams Syndrome Genotype and Phenotype WS is a contiguous gene disorder caused by a hemizygous microdeletion on the long arm o f chromosome 7 (Ewart, Morris, Atkinson, Jin, Stemes, Spallone, Stock, Leppert, and Keating, 1993). The disorder occurs once in about 25,000 to 50,000 live births (Beuren, 1972). Sixteen genes have thus far been mapped to the deleted region (Meng, Lu, Zhizhong, Green, Massa, Trask, and Morris, 1998). The list o f phenotypic characteristics that accompany this genetic disruption is long and varied. Physical features include a characteristic set o f facial features (flat nasal bridge, star-shaped iris, prominent lips), musculoskeletal features (joint limitations), endocrine features (infantile hypercalcemia), renal problems (small or solitary kidneys), and cardiovascular problem s (greatly increased susceptibility to heart valve defects— a major health concern) (Korenberg, Chen, Hirota, Lai, Bellugi, Burian, Roe, and Matsuoka, 2000). N eurological and neurocognitive features include mild to moderate mental retardation, poor coordination, friendly, loquacious personality, enhanced musical ability, and relatively spared language development (Korenberg et al. 2000). Further details about both linguistic and other cognitive abilities have been examined in detail by numerous researchers, and these are reviewed in section 1.4.

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The diagnosis o f WS is simple and uncontroversial. A genetic test (florescence in situ hybridization, or FISH) probes for the deletion o f the first gene that was implicated in the deleted region—the elastin gene (Ewart et al., 1993). The availability o f a definitive m arker sets WS apart from many other disorders (Specific Language Im pairm ent, Broca’s aphasia, autism, etc.), and removes any concerns about whether different researchers testing different individuals are in fact comparing people with different disorders.

1.4 Review o f Cognitive Abilities and Disabilities in Williams Syndrome 1.4.1 Full Scale IQ When tests that examine full scale IQ are adminstered, WS groups typically achieve an average IQ between 50 and 60. For example, one group o f 82 WS individuals achieved an average full scale IQ on the WISC/WAIS o f 55 (SD=11, range=40-90; Bellugi, Lichtenberger, Jones, Lai, and St. George, 2000; Wechsler, 1974, 1981). Another group o f 38 WS individuals, age 2—18, achieved an average IQ on the Differential Abilities Scale (the DAS) o f 59 (SD=11, range—38—84; Mervis, Morris, Bertrand, and Robinson, 1999; Elliot, 1990). Similar average scores (in the mid-50s to Iow-60s range) have been reported by other researchers using these and other IQ tests (Karmiloff-Smith et al, 1997; Jarrold, Baddeley, and Hewes, 1998; Howlin, Davies, and Udwin, 1998; Greer, Brown, Pai, Chodry and Klein, 1997). This IQ range is similar to that observed in individuaJs with Down Syndrome1. 1 Bellugi and colleagues (2000) report that “adolescents with WMS [Williams Syndrome] and those with DNS [Down syndrome] in our studies score equally poorly across the board on IQ tests such as the Wechsler Intelligence Scale for Children-Revised (WISC-R; Wechsler, 1974) or Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, 1981). In each o f these subject groups, there was no clinically significant difference between Verbal and Performance IQ scores on the Wechsler scales. In

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1.4.2 Spatial Cognition Deficits The m ost well-known cognitive deficits in WS concern deficits o f spatial cognition. Am ong these, the most widely documented problems surface in tests o f visuo-spatial construction, such as freehand drawing, copying o f drawings (as in the Developmental T est o f Visual-m otor Integration, Beery and Buktenica, 1967), and assem bling o f patterned blocks to match a model (as in the Pattern Construction sub-test o f the DAS, Elliot, 1990). WS children and adolescents typically score worse on these tests than their full scale IQ scores would predict, and worse than m ental-age-m atched comparison groups (both normally-developing groups and groups with other etiologies o f mental retardation; Bellugi et al.1988, 1992; Mervis et al. 1999, Bertrand, M ervis, and Eisenberg, 1997). These deficits do not seem to reflect motor problems p e r se, as WS children are reported to be able to trace drawings (Bellugi et al, 1988).

Likely related to these deficits are well-documented deficits in spatial memory and local vs. global spatial processing. Both were likely responsible for the results o f a series o f studies reported by Bihrle, Bellugi, Delis, and Marks, 1989. B ihrle and colleagues showed 14 WS adolescents (age 9—18) pictures of large single letters or shapes that were m ade up o f smaller single letters or shapes like the one shown in Figure 1 (Delis, Robertson and Efron, 1986). After looking at a given stimulus for 5 seconds, a 5-second delay was imposed, and then participants were required to reproduce the stimulus from m em ory. WS participants reproduced the small local elements o f the stimuli very frequently (over 70% o f the time), but reproduced the global configuration m uch less

addition, both groups showed equal degrees o f impairment on cognitve probes such as the Halstead Reitan Neuropsychological Battery (Reitan & Wolfson, 1985), and general tests o f conceptual knowledge, information, or math achievement, and Piagetian tests o f conservation, including conservation o f number, weight, and substance (Bellugi et al, 1992; Bellugi et al., 1994; Bellugi et al., 1996).” (p. 10)

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Figure 1. Sample Item from Bihrle et al., 1989

Y YY Y Y Y Y Y Y Y YY frequently (only around 20% o f the time). The delay was an important factor in accounting for this poor performance with the global configuration, because when the delay was removed entirely (making it a copying task) accuracy on global configuration increased to about 50% (while accuracy on local elements did not change substantially). Additional evidence for a spatial memory deficit comes from WS performance on the Corsi blocks test (Milner, 1971), where participants must recall a sequence o f tapped blocks from a 3x3 block array. Many researchers have demonstrated that WS individuals have a much lower span on this spatial memory task than they do on a minimally different digit span task requiring not spatial memory but auditory-verbal memory (Wang and Bellugi, 1994; Jarrold, Baddeley, and Hewes, 1999; Vicari, Brizzolara, Carlesimo, Pezzini, and Volterra, 1996). Exactly the opposite pattern is reported for Down Syndrome individuals o f similar MA (Wang and Bellugi, 1994; Jarrold, Baddeley, and Hewes, 1999). Therefore, spatial working m em ory is a clear deficit in WS, and may be responsible in part for problems reported in visuo-spatial construction tasks.

Despite the extreme deficits witnessed in WS for visuo-spatial construction abilities, there is some evidence for relatively good v isu a l -perceptual abilities in WS. For example, Wang, Doherty, Rourke, and Bellugi (1995) showed that 10 WS adolescents (age 11—18) performed roughly appropriate for their MA on tests o f visual neglect and visual closure, and performed better than their MA on tests o f object identification with

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non-canonical viewpoint, a finding that was later confirmed by Landau and Hoffman (2000) with a non-disordered MA comparison group (the Bellugi group had been compared to a Down syndrome cohort). WS children also are able to extract form from motion: Jordan, Reiss, Hoffman, and Landau (2000) demonstrated that WS children are able to integrate information from white dots on a black background that simulate the motion o f a moving human figure (so-called t£biological motion”, Johannson, 1973), even when these dots are embedded in a background o f moving “noise” dots. Furthermore, Stevens and Karmiloff-Smith (1997) reported that when a group o f WS individuals was asked to describe stimuli like those in Figure 1, the majority of them mentioned both the parts and the whole, suggesting that the difficulty that WS individuals have with reproducing the global shape in a drawing task does not reflect a perceptual deficit.

Despite these results, the full picture on visual-perceptual abilities in WS is a bit more equivocal than the work above suggests. For example, WS children are not as good as their non-disordered MA-mates at mentally extending the (imagined) horizontal and vertical axes o f a depicted object. In work with unimpaired adults, Hayward and Tarr (1995) showed that when a second object (e.g. a circle) falls along the perceptuallyimposed axis o f a reference object (e.g. the imagined vertical axis of a square), memory for the position o f the circle is improved (relative to when the circle is the same distance from the square, but off axis). Zukowsld, Schwartz, and Landau (1999) demonstrated that WS children show a smaller axis advantage in this task than non-disordered children o f the same MA. In other work, Bellugi, Lichtenberger, Mills, Galaburda, and Korenberg (1999) report that WS individuals consistently achieve a test level of “severely deficient” in the Benton Judgment o f Line Orientation test—a test which requires them to match a pair o f lines at some orientation to the correspondingly oriented lines in a larger array

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(Benton et al, 1983a). Furthermore, these perceptual difficulties in WS seem to extend into the realm o f visually guided action in the 3-dimension world. Atkinson, King, Braddick, Nokes, Anker, and Braddick (1997) showed that WS children perform worse on a typical test o f visually-guided action than non-disordered chronological age mates (the test involves “posting” an envelope-sized card through a narrow slot; Milner and Goodale, 1995). This result has been replicated with another group o f WS children (Dilks, Landau and Hoffman, and Siegfried, 2001), who also demonstrated worse-thanexpected performance for their M A relative to unimpaired children on a “m atching” version o f the task, where they m erely had to say “stop” when a m annequin hand was rotated to an angle that would allow the card to be posted.

1.4.3 Piagetian Conservation Tasks Bellugi, Bihrle, Neville, Doherty, and Jem igan (1992) report that WS children and adolescents (age 10—16) are not able to pass standard Piagetian tests o f conservation skills. Such tasks measure reasoning skills that very young children do not seem to possess, such as the ability to understand that spreading out 5 cookies on a table does not change the total number o f cookies there are. Non-disordered children are able to master conservation tasks well before age 8 ; this includes conservation o f two-dim ensional space, number, substance, continuous and discontinuous quantity, and weight. Most o f the WS group tested by Bellugi and colleagues, scored at floor across the board for these tests.

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1.4.4 Mathematics and Number Concepts Arithmetic is reported to be extremely difficult for most individuals with WS, although Bellugi et al. (2000) report that “some are able to master addition and, in a small number o f cases, subtraction and division as well” (p. 9). These authors also note that most WS people have great difficulty in performing everyday tasks that depend on very basic mathematics, such as making change, balancing a check book, and cooking from recipes. They also report that many individuals with WS “would rather receive 50 pennies than five dollars as a reward” (p. 10). Experiences that we have had in our lab have been similar—for example, when one 10-year-old boy was given a twenty dollar bill and a five dollar bill, he excitedly commented “two dollars!” indicating a misunderstanding that the num ber o f bills maps directly onto their magnitude (and perhaps also suggesting a misunderstanding o f how valuable two dollars is). Bellugi and colleagues, also report that WS individuals give wildly inappropriate estimates o f the length or weight o f objects, such as estimating the length of a dollar bill as five feet.

Johnson (2000) reported a wide range o f additional conceptual deficits in the domain o f num ber in WS. She tested 5 individuals with WS (mean age 19 yrs) on their ability to compute cardinality (i.e. to count objects), and on their understanding o f concepts involving zero, infinity, and fractions. She found that they performed worse than 9-yearold typically-developing controls (matched for verbal IQ) on all measures o f number concepts tested except cardinality. For example, they had extreme difficulty answering questions like “W hat’s the very smallest number?” (9-year-olds routinely say “0”), and “I f you kept counting all your life would you ever reach a highest number?”, and they did very poorly at placing fractions on a number line and making magnitude judgments

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corresponding to fractions. What these m ore difficult concepts have in common that is different from cardinality, according to Johnson, is that they all “involve a reconceptualization o f numbers from entities that refer to whole individuals (i.e. the natural numbers), to entities that do not (zero refers to nothingness, infinity refers to the absence o f boundaries/limits, and fractions refer to parts o f wholes).” Thus WS individuals, in Johnson’s view, lack w hatever mechanisms are responsible for a reconceptualization that she believes is necessary to move from a child-like understanding o f number to an adultlike understanding.

1.4.5 Folkbiology Concepts Another domain in which it has been claimed that WS individuals never attain adult-like conceptual knowledge is folkbiology (Johnson and Carey, 1998). For example, according to Johnson and Carey, between age 4 and age 10 normally-developing children usually undergo a dramatic shift in their understanding of concepts like person and animal. Preschoolers have an elaborate concept for person, and they distinguish animals from non-animals, and furthermore they are able to use these concepts for reasoning. However, it is not until a later age (between 7 and 10) that they come to the folkbiological understanding o f people as one animal among many, or o f animals and plants being one ontological kind (living things). These researchers found that 10 WS individuals (average age 24 years) had not achieved the adult-like understanding o f a variety o f folkbiological concepts, but performed instead like normal 6-year-olds.

By contrast to the cognitive deficits I have laid out thus far, there are a few non-linguistic cognitive abilities that look relatively good in WS—primary among those are auditory

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short term memory, face processing, and theory o f mind.

1.4.6 Auditory Short Term Memory As mentioned earlier in the discussion o f spatial memory deficits in WS, many researchers have demonstrated that WS individuals perform much better on auditory memory span tasks (with either digits or words) than on spatial memory span tasks (Wang and Bellugi, 1994; Jarrold, et al., 1999; Vicari et al., 1996), a pattern which is opposite to the one seen in children o f the same MA who have Down syndrome. Mervis et al. (1999) compared digit span in a large WS group to digit span in an unimpaired group matched for chronological age. In a study o f 104 WS individuals (age 4—52), they found that the majority o f scores were normally distributed with a mode centering around the 14th percentile. They conclude that “auditory short-term memory is a definite strength for individuals with Williams syndrome” (p. 76).

There is some evidence, however, that not all o f the normal factors responsible for auditory memory span operate to the normal degree in WS— differences appear when the task is a word span task, and when the factors involve word frequency or semantic processing. For example, when asked to recall a sequence o f unrelated words from immediate memory, WS children do not demonstrate the standard primacy effect (an advantage for words at the beginning o f the list), which is thought to reflect semantic processing o f these words, whereas they do demonstrate the standard recency effect (an advantage for words at the end o f the list), which is thought to reflect phonological processing (Vicari, Brizzolara, Carlesimo, Pezzini, and Volterra, 1996). Similarly, word span performance by WS children is affected in the normal way by word length and

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phonological similarity variables, but it is not affected in the normal way b y word frequency (Vicari, Carlesimo, Brizzolara, and Pezzini, 1996). That is, span length is shorter for long words than for short words, and it is shorter for phonologically similar words than for dissimilar ones, while at the same time, span length does not decrease to the normal degree when the word string contains low frequency words. In sum, auditory short term memory is a strength in WS individuals, but this is primarily due to auditory and/or phonological factors, and not to lexical factors that normally operate.

1.4.7 Face Processing Bellugi and colleagues (2000) report that a group o f 16 WS individuals who had performed at the “severely deficient” level on the Benton Judgment o f Line Orientation Test (mentioned earlier) simultaneously performed at nearly normal adult level in the face m atching subtask o f the same test battery (Benton et al., 1983b). Similarly good perform ance was seen with other face processing tasks such as the W arrington Face Memory Test (Warrington, 1984) and the Mooney Closure Task (Mooney, 1957).

A num ber o f studies have now provided evidence that good performance on face processing tasks in WS actually reflects abnormality in this area o f cognition, although again the results are somewhat mixed. For example, Karmiloff-Smith (1997) reported that 10 WS adults showed less o f a drop in performance than normal adults when processing inverted faces. However, Mills and colleagues reported that 18 WS adults were identical to non-disordered adults in their behavioral responses to inversion o f face stimuli. Both groups showed a 10% drop in same/different judgments for face stimulus pairs as well as a 50 msec slower reaction tim e for inverted faces compared to upright

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faces (Mills, Alvarez, St. George, Appelbaum, Bellugi, and Neville, 2000).

D espite these conflicting results, additional work from both groups o f researchers suggests other evidence for abnormality. For instance, Karmiloff-Smith (1997) also showed that good face processing scores for WS adults reflect very good scores with face stimuli that allow for feature-by-feature componential analysis, but chance performance with face stimuli that require configurational processing. Furthermore, in the study (mentioned above) by Mills and colleagues, event related potentials (ERPs) were recorded dining the behavioral study, and the results suggested both developmental delays and abnorm al patterns. Early components o f the ERP waveform that are taken to reflect face perception were abnormal in every one o f the 18 WS adults the authors tested, and in every WS child that they have not yet published data on. This early abnormal waveform was the same for all o f the WS participants, and the authors report that the pattern is one that they have not observed in normal adults, children, or infants at any age, nor in any disordered populations that they have tested (including Down syndrome, language impaired children, and children with early left- or right-hemisphere brain injury). By contrast, late components o f the ERP waveform (during the same/different judgm ent task) that are taken to reflect face recognition were quite similar among WS adults to the pattern seen in normal 13-year-old children. Unlike non-disordered adults, who show distinct ERP patterns to mismatched faces when the stimuli are upright vs. inverted, non-disordered 13-year-olds show much m ore similar ERP patterns for upright and inverted faces, and WS adults display the latter pattern too.

Thus, face processing is a fairly strong area among WS individuals, but the brain mechanisms that underlie face processing may be somewhat unusual in this population.

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1.4.8 Theory of Mind Several studies have now documented successful performance by WS individuals on theory o f mind tasks— tasks which require the participant to interpret the behavior o f others within a mentalistic explanatory framework (Karmiloff-Smith, Klima, Bellugi, Grant, and Baron-Cohen, 1995; Tager-Flusberg, Boshart, and Baron-Cohen, 1998). For example, Karmiloff-Smith and colleagues report that by age 9, WS children are able to pass false belief tasks—that is, they are able to predict someone’s behavior on the basis o f that person’s beliefs, even when those beliefs are known to the child to be incorrect (94% o f 15 WS subjects age 9-23 passed this test). Although Tager-Flusberg and Sullivan (2000) caution that this ability does not appear at the normal developmental age (i.e. 4 years) in WS (only 25% o f their 21 WS subjects age 4-8 passed), they do report MAappropriate performance on a developmentally easier task which may be a precursor—the ability to use mental states to explain someone’s behavior (as opposed to predicting it). For example, a typical story in a test like this might involve a man leaving a cake in the cupboard and then leaving, and then a woman entering the kitchen and putting the cake in the refrigerator. In this context, although younger WS children might not be able to correctly predict where the man will look for the cake when he returns (they would wrongly predict the refrigerator), they would nevertheless be able to explain why the man in fact looked in the cupboard (they would say that the man thought it was there because he left it there). Thus, WS individuals do seem to develop theory o f mind, but it is delayed relative to the normal developmental age o f 4 years.

To summarize this background on cognitive abilities in WS, WS individuals show mildto-moderate levels o f overall retardation, with particular weaknesses in the areas of

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spatial cognition, reasoning, and math skills, and with an inability to transition between childlike and adultlike folk conceptualizations about number and the biological world. By contrast to these deficits, they show relatively good auditory short term memory and face processing abilities, although their strengths in these areas are accompanied by some deviations from normal patterns. And finally, they are delayed but ultimately proficient at interpreting the behavior o f others within a mentalistic framework. With this background in mind, we next move to am examination o f WS linguistic abilities.

1.5 Review and Discussion of Language Abilities and Disabilities in Williams Syndrome

1.5.1 Production o f Complex Sentence Structures In the earliest report o f th e surprising proficiency o f WS language, Bellugi, Marks, Bihrle, and Sabo (1988) discussed three 11—16 year old WS children who showed characteristics o f the cognitive profile described above (IQs around 50, visuospatial construction skills typical o f 5-year-olds, and failure at conservation tasks normally mastered by age 7), but w ho seemed to command sophisticated linguistic skills. The authors reported that their expressive language was “complex in terms o f morphological and syntactic structures including full passives, embedded relative clauses, a range o f conditionals and multiple embeddings” (p. 183). However, although examples o f speech provided in the paper w ere impressive, few details about language production abilities beyond the description quoted above were provided in this early report.

In later reports from Bellugi and colleagues, quantitative production data were provided

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for larger groups o f WS children and adolescents, including results from tests o f sentence completion and sentence correction (Bellugi et al., 1992; Bellugi et al., 1994; Rossen et al., 1996; Bellugi et al., 2000). Two structures that were elicited in this battery illustrate the degree o f complexity that is apparent in the expressive language o f WS individuals. These included tag questions and conditionals.

Tag questions are questions that m ay be “tagged” onto the end o f a declarative clause in order to request confirmation from the listener, as in “The pizza man w asn’t late, was he?” and “Colin likes olives, d o e sn ’t he?" As these examples demonstrate, tag questions m ust reverse the polarity (negative/affirmative) o f the declarative clause that precedes them, they must provide an appropriate pronoun to refer back to the NP subject of the declarative, they must use the sam e auxiliary as the declarative clause, and i f there is no auxiliary in the declarative clause, they must introduce do-support. As Bellugi, Wang, and Jemigan (1994) note, this is all done for the “trifling semantic effect” o f a request for confirmation (p. 30). This complexity provides a lot o f opportunities to make an error. A group o f 10 WS adolescents (age 10-20) in these studies averaged 20/48 grammatically correct tag questions. By comparison, an IQ-matched DS group averaged 1/48 correct tags.

Conditionals require control o f the subjunctive mood. In the test reported by Bellugi and colleagues (2000), children were asked to follow up experimenter prompts such as “What i f you were a bird?” Seven WS teens and adults produced gram m atically correct responses 83% o f the time in this study. Sample responses include “You could fly, you could have babies, fly north or south, east or west”; “Good question. I’d fly through the air being free”; and “I would fly and if I liked a boy, I would land on his head and start

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chirping.” A comparison group o f 7 Down Syndrome individuals responded with grammatically correct responses onlly 29% o f the time. Samples responses from them include “Fly in the air”, “I don’t fly” and “I not a bird, you have wing”.

Additional data on the production abilities o f a much larger sample o f WS children was provided by Klein (1995). Klein examined the syntactic complexity o f spontaneous speech from WS children using the Index o f Productive Syntax (IPSyn; Scarborough, 1990). To calculate IPSyn score, a 100-utterance sample o f spontaneous speech is examined for the presence o f structures that match a 56-item list o f NP, VP, question, and clausal “constructions”2. Klein calculated IPSyn scores for 39 WS children, aged 2-12 years, with a mean age o f 7. Surprisingly, these children received an average score lower than the average score that Scarborough (1990) had reported for normal children aged 3 years, 6 months (Mervis et al. 1999). Despite this difference in absolute scores, Klein found that the pattern o f acquisition for the WS children was similar to the pattern found in normal development in two important ways. First, the number o f WS participants who received the maximum points for each construction in the IPSyn correlated —.90 with the relative complexity o f the item (as determined developmentally by Scarborough). That is, the WS children seemed to be acquiring the structures in a normal developmental order, despite an apparently substantial delay. Second, when MLU and IPS3m scores were plotted against each other mdividual-by-individual, the relationship between the two was nearly identical to that seen in normally-developing children. That is, as the WS children’s utterances increased in length, they showed the expected degree o f increase in 1 Here are the simplest and most complex construction from each category. NP: “proper, mass or count norm”, “bound morpheme on noun to make it an adjective”; VP: “any verb”, “past tense copula”; Questions: “intonational question”, “tag question”; Clauses: “two word structure”, “fronted or center embedded subordinate clause” (quotes are Klein’s (1995) paraphrases o f items listed in Scarborough, 1990).

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syntactic complexity. This pattern held through the highest MLU achieved by this group (an MLU o f 5). Other retarded groups (autism, Fragile-X syndrome and Down syndrome) also show a normal degree o f increasing complexity as their utterances increase from an MLU o f 1 to an MLU o f 3, but at this point the similarity to the normal pattern breaks down (Scarborough, Rescorla, Tager-Flusberg, Fowler, & Sudhalter, 1991).

1.5.2 Language is Delayed in Williams Syndrome The apparent discrepancy between the reports from Bellugi and colleagues and Klein with regard to the production o f complex syntactic structures may be due to the different ages o f the WS groups (adolescents vs. 2-12 year-olds). Jarrold, Baddeley, and Hewes (1998) have argued that verbal and nonverbal abilities develop at different rates in WS, at least as measured by the subtests o f the DAS (Elliot, 1990). At an early age, the discrepancy between these abilities is quite small, but as verbal age increases, the gap widens. A clear gap does not appear between the two measures until age 100 months (age 8; 4).

It may be that this pattern o f differential developmental trajectories for verbal and non­ verbal abilities does not scale up to include more complex language abilities than those tested on the DAS (which focuses primarily on vocabulary knowledge). But it is by now well established that WS language is indeed delayed in the early stages. For example, various researchers have documented that WS infants are delayed in producing their first words (Thai, Bates and Bellugi, 1989; Harris, Bellugi, Bates, Jones, and Rossen, 1997; Capirci, Sabbadini, and Volterra, 1996). Capirci et al. (1996) additionally reported delayed emergence of bound and free morphology in their case study o f a 4-year-old

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Italian girl with WS.

But even taking into account that WS language is delayed, failure to produce particular structures in spontaneous speech cannot be taken as definitive evidence for lack o f knowledge o f those structures. This general concern about spontaneous speech is particularly relevant in the case o f K lein’s study, as the comparison group o f normally developing children was sampled by different researchers than Klein’s WS children, and we do not know how this difference m ight have influenced the kinds o f things that the two groups happened to talk about during the recording period.

Because children may know m ore than their spontaneous speech happens to reflect, comprehension tests offer some advantages for language assessment— they allow an evaluation o f children’s understanding o f structures that they may not happen to produce in a given testing session. That is, they provide more experimenter control over which structures are being tested. W e look next at a large body o f work examining WS language abilities through the use o f comprehension tests.

1.5.3 Performance on Comprehension Tests There is some evidence that WS children can perform quite well in comprehension tests. The kinds o f comprehension tests that are most often reported for WS groups are sentence-picture matching tests, wherein participants hear a word or sentence and then select from a set o f pictures the one picture that the word or sentence best describes. The earliest reports o f language comprehension results in WS also come from Bellugi and colleagues (Bellugi et al., 1988; Bellugi et al., 1992; Bellugi et al., 1994; Rossen et al.,

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1996). Based on samples o f 3 to 10 WS individuals (age 10-20), Bellugi and colleagues reported 80—90% success rates on comprehension o f reversible passives, negation3, and conditional clauses. For example, they could choose the correct picture to match a sentence like “The horse is chased by the man” (while correctly failing to choose a picture depicting a horse chasing a man). Good comprehension by WS children and adolescents was also demonstrated by responses to the conditional prompts that were discussed in section 1.5.1 (responses when an experimenter asked “W hat if you were a bird?”; Bellugi et al., 2000).

Clahsen and Almazan (1998) confirmed high rates o f success with reversible passives in a test borrowed from van der Lely (1996), in this case with 4 WS individuals, age 11—15. These 4 WS participants yielded 100% correct performance on this task, which is slightly higher than the performance o f the two normal 5-year-olds who were the matched controls for the two lower-IQ children. Karmiloff-Smith et al. (1997) also found errors on reversible passives to be relatively low (rates around 20%) am ongst her 20 WS participants (age 8-34, mean age o f 18).

Clahsen and Almazan (1998) additionally gave their 4 WS children a test o f Binding Conditions A and B (using a procedure adapted from Chien and W exler, 1990, and using m aterials borrowed from van der Lely and Stollwerck, 1997). These grammatical constraints describe adult patterns o f interpretation o f pronouns (e.g. he) and reflexives (e.g. himself). In this task children examine a picture, and are then told the names o f all o f the characters. They are than asked to answer a yes/no question that contains either a pronoun (e.g. him) or a reflexive (e.g. himself). For example, the question might be “Is 3 Details o f the negation test are not provided, but cf. Bellugi and Klima, 1966, Bellugi, 1971.

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Mowgli scratching him?” or “Is Mowgli scratching himself?” To perform absolutely correctly on this task, participants must answer yes whenever the sentence matches the picture, and they must answer no whenever the sentence does not match the picture. Clahsen and Almazan’s 4 WS subjects scored 100% correct on every sentence type, again slightly surpassing some o f the normal MA-matched controls.

However, despite these examples o f success, WS groups often experience problems in sentence-picture matching tests. A case in point comes from Karmiloff-Smith, Tyler, Voice, Sims, Udwin, Howlin, and Davies (1998). These authors examined a variety o f grammatical structures with a picture-matching test developed by Black, Nickels, and Byng (1991). Eight WS participants (age 15-34, with a mean age o f 20) were compared to 18 non-disordered adult controls (age 19—29). The controls performed almost perfectly on all o f the structures examined, while the WS participants made an average o f 24% errors (14—37%, depending on the structure). Interestingly, a second control group was then included—normal elderly adults (age 60—75), who averaged 17% errors on the same test. Importantly, the error rates o f the elderly adults closely tracked the errors of the WS individuals, structure by structure. Error rates for the WS and the elderly groups by structure were as follows:

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Table 1. Error rates on a Language Comprehension Test: WS vs. The Elderly WS

Normal Elderly

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31

26 24 17 14

23 21 10 3

Both actives and passives with non-agentive verbs (e.g. shock and be shocked by) Deverbal Adjectives Adjectives (e.g. shy, nasty) Passives with agentive verbs (e.g. be photographed by) Actives with agentive verbs (e.g. photograph)

The elderly normal group was not unusual in this regard—a similar pattern o f difficulty was reported by the developers o f the test themselves (Black et al. 1991) with another group o f 21 normal adults, aged 15-80 (all but 3 were over 50). Numerous researchers have now reported similar or worse error rates for WS groups with another sentence-picture matching task—the Test for Reception o f Gram m ar (or TROG, Bishop, 1983). The TROG includes both active and full reversible passive sentences (e.g. The girl is pushed by the horse), a few size comparatives (e.g. The knife is longer than the pencil), a few spatial descriptions (e.g. The comb is below the spoon), various kinds o f relative clause structures (e.g. The cow chasing the cat is brown), and a large variety o f structures involving the simultaneous manipulation o f negation and coordination.4 Karmiloff-Smith et al. (1997) report item-by-item error rates from th e TROG for 18 WS participants (age 8—34, average 18 years). The group yielded an average “test age” on the TROG o f 6 years 3 months, while their nonverbal mental age as measured by the Ravens

4 The sentences manipulating negation and coordination simultaneously had the folio-wing structures: 1. the X but not the Y [is adj/verb] 2. the X is [adj/verb] but not [adj/verb] 3. not only the X but also the Y [is adj/verb] 4. the X is not only [adj/verb] but also [adj/verb] 5. neither the X nor the Y [is adj/verb] 6. the X is/has neither [adj/noun] nor [adj/noun]

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Coloured Matrices (Raven, 1986) was 6;0. Karmiloff-Smith and colleages again took this to indicate that “claims about the intactness o f WS morphosyntax have to be modified” (p. 248). Relative clauses embedded in full sentences were among the most error-prone items on the test. The block o f items containing center-embedded subject gap relative clauses (e.g. the boy chasing the horse is fa t) yielded an average error rate o f 28%, the block containing right-branching subject gap relative clauses (e.g. the dog chases the horse that is brown) yielded 38% errors, and the block containing center-embedded object gap relative clauses (e.g. the cat the cow chases is black ) yielded 68% errors.

Similarly, Mervis et al. (1999) tested a larger group o f 77 WS participants (age 5—52) with the TROG and reported a mean standard score corresponding to the 4th percentile. Nevertheless, given that 56% o f these WS participants scored in the normal range (standard score > 70), Mervis et al. concluded that “grammatical comprehension is a relative strength for individuals with Williams syndrome.” However, even these authors point out that relative clauses m ay be a particular weakness: “ only 18% o f the participants (22% o f the adults) passed the block assessing relative clauses (right branching), and only 5% (9% o f the adults) passed the block assessing embedded sentences (left branching)” (p. 85).

Finally, Volterra et al. (1996) gave 17 Italian WS children (age 4; 10 to 15;3) an Italian version o f the TROG and compared their performance to 116 unimpaired children whose actual age matched the tested MA o f the WS children (3; 8 to 6; 8). Most o f the WS children scored significantly worse than the controls5. But again, the pattern o f diffftculty s Although the article mentions 17 WS children, the scatterplot showing raw score on the TROG as a function o f age has only 7 dots labeled as WS children. 6/7 o f these appear below the minimum TROG score achieved by their MA controls.

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for particular item types (prepositions, relative clauses, passives) was nearly identical for the WS and control groups (cf. Fig. 3 in Volterra et al, 1996).

We have seen that non-disordered children and the elderly show similar patterns of difficulty as people with WS on tests like the TROG. In fact, difficulty on these tests even extends to non-disordered native-speaker adults. Bishop, the creator of the TROG, reports (1998, p. 157) that even when this test is administered to normal adults with no time pressure, only a minority of them get all 4 items from the last block correct—this is the block with center-embedded relative clauses with object gaps (all 4 items in a block must be correct in order to receive any credit for that block). To illustrate the difficulty, consider one of the items from this block of the test, shown in Figure 2. Children are asked to point to the picture where the circle the star is in is red. Figure 2. Difficult TROG Example*

o




0

©

0

&

©

*ChiId is asked to point to the picture where th e c irc le the sta r is in is red.

Thus, young children, elderly people, and adults— none of whom have language disorders— show similar patterns o f difficulty on these tests as WS groups do. The

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similarity across age groups and across both disordered and non-disordered groups suggests that these tests likely require more than just linguistic knowledge. Whatever abilities these tests require in addition to grammatical knowledge, those abilities exert enough o f an influence on performance that they even occasionally mask the linguistic competence o f mature native-speaking adults.

These observations cast doubt upon the validity o f these tests as definitive measures o f linguistic competence— in any population. And given that we know relatively little about the additional abilities that are required in order to perform well on these tests, we should be particularly cautious about using them to assess language in populations with compromised cognitive abilities.

Evidence that this caution is well-deserved comes from a recent study reported by Gage, Hickok, and Huntley-Fenner (submitted). These authors compared two tests o f relative clause ability against each other and found a large discrepancy in the scores obtained on the two tests by two adult WS individuals. A sentence-picture matching test yielded 100% correct responses to items with right-branching subject gap relatives (e.g. “point to the boy who is washing the girl”) but only 63% correct responses to items with object gap relatives (e.g. “point to the boy who the girl is washing”). By contrast, the same two adults achieved near-perfect scores in a plausibility judgment task involving relative clauses that were minimally different from those tested in the sentence-picture matching test.6 This difference obtained despite the fact that the two tests entailed comprehension 6 In this second test, subjects were asked to decide whether the action described in a sentence is “like something you might see in the real world” or whether it is “silly, like something you might see in a cartoon”. Some test sentences include plausible subject gap relatives (e.g. I saw a man who walked a dog) and object gap relatives (e.g. I saw a dog that a man walked), while other test sentences include implausible subject gap relatives (e.g. I saw a dog that walked a man) and object gap relatives (e.g. I saw a man who a dog walked).

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o f the same structures.

In light o f these issues regarding comprehension tests, it seems clear that the facts about language competence in WS deserve further examination. I think elicited production tests may be better suited to the task o f evaluating language competence in WS, for reasons that I discuss next.

1.5 4 Elicited Production may Reveal Competence Masked by Cognitively Difficult Comprehension Tests Language production is in some ways a much easier task than comprehension, and in some ways much harder. It is easier in one sense described by Bock (1995): “Speakers begin with an interpretation, in the form o f a message. The message may be apprehended all at once, and without ambiguity”. This contrasts with language comprehension, where listeners have to piece together both the syntactic structure and the intended message incrementally, since words are encountered sequentially. In the context o f a sentencepicture matching test, these dual construction jobs have to proceed in concert with other jobs as well— surveying pictures, comparing pictures to each other, suppressing distractor pictures that are m arginally different from target pictures, etc. However, language production is harder than comprehension in a sense described by Thornton: “It is highly unlikely that a child could put words together in a particular way accidentally” (Thornton, 1998, p. 78). For example, given the grammatical complexity inherent in sentences containing relative clauses, there is a good deal o f room for error in getting every grammatical detail correct when producing them. One could know a lot about relative clauses and still make mistakes in producing them. But it would be difficult to get all the

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details right merely by accident—grammatical details simply cannot be faked.

Given these different demands o f comprehension and production tests, I think that production tasks— which remove some o f the processing factors that have been shown to influence the performance o f even unimpaired adults, but which do not sacrifice rigor as a m easure o f language competence— are m ost suitable for a WS population. But spontaneous production is not a very efficient or definitive method for evaluating competence with particular syntactic structures. For this reason I think elicited production studies are called for. As discussed earlier, this technique involves placing children in communicative situations that uniquely call for the production o f particular structures o f interest.

To this end, two o f the four studies that I report here are designed to elicit the production o f two classes o f syntactic structures that are o f interest. For the first, I examine the structure that has been the most prone to difficulty on comprehension tests— embedded relative clauses. It is crucial to re-examine relative clauses, because although these are complex structures, carefully controlled experiments have shown that they are produced correctly by normal children before age 4 (e.g. Hamburger and Crain, 1982). Despite the high error rates observed with relative clauses on comprehension tests, there is a variety o f evidence to suggest that relative clause competence is strikingly good in WS. First, Bellugi and colleagues (1988) reported the use o f relative clauses— even ones embedded in full sentences— in the spontaneous speech o f WS individuals. Second, tests in our own lab that were designed to elicit spatial descriptions often incidentally elicited relative clauses that were well formed and seemed to be produced with ease and fluency. Third, the study reported by Gage and colleagues (submitted) suggested that the same WS

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individuals who perform poorly with relative clauses in a sentence-picture matching test nonetheless perform at near-ceiling levels on a different task testing exactly the same structures.

Although these latter studies suggest that relative clauses are well within the grammatical abilities o f WS individuals, the full picture is not yet complete. The production data are thus far anecdotal, and the plausibility judgment results from Gage et al. did not test the full range o f relative clause embeddings that are included in the TROG—indeed it left out the center-embedded relative clauses that present W S individuals (and everyone else) with the m ost difficulty. I therefore designed an elicited production study to test the frill range o f relative clause structures examined in the TROG. This study is reported in chapter 3.

For the second elicited production study, I chose to examine a structure that nondisordered children show difficulty with until quite a late age— negative questions (e.g. What don’t you like?). Previous work from Bellugi (1971) and Thornton (1993) show that norm ally developing children exhibit non-adultlike patterns in their negative questions sometimes as late as age 5 (e.g. they m ight say “What do you don’t like?” or “W hat you don’t like?”). This contrasts with com pletely adultlike production o f affirmative questions at the same age. The WS children in our study have a MA between 4 and 7 years, so the inclusion o f this test provided an opportunity for the WS group to surpass their MA-matches on a structure that is know n to be difficult for unimpaired children. However, even if the WS children do not surpass the controls, the study will reveal whether WS children are prone to the same kinds o f errors as normally developing children in the course o f acquisition in this domain.

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1.5.5 Morphosyntactic Operations In addition to past reports o f the comprehension and production o f particular clause-level structures, several researchers have reported data o n sub-clausal morphosyntactic abilities in WS. As early as 1988, Bellugi and colleagues reported finding “occasional errors o f overgeneralization o f morphology and pronoun usage” in the speech o f th eir WS adolescents (p. 183).

Clahsen and Almazan (1998) examined m orphology more systematically for four WS children (age 11—15), and found extremely sm all numbers o f omissions or incorrect forms o f determiners, verbal inflection m arkers, prepositions, pronouns, plural -s, and genitive -s. However, they did report a robust m orphological error in WS productions— namely, unusually high rates o f overapplication of the regular past tense ending to irregular verbs (e.g. sw im m ed) and unusually high rates o f novel words rhyming with existing irregulars (e.g. shrimmed), and/or high rates o f bare verb forms in contexts requiring the past tense7. This poor performance with irregular and pseudo­ irregular verbs occurred side-by-side with very good performance with regular and pseudo-regular verbs (e.g. drop and sp u ff being tensed as dropped and spuffed at rates mostly exceeding 90%). Clahsen and Almazan concluded that morphological difficulties in WS are confined to contexts where they are required to access lexical information that must be rote-memorized. Because the WS children did so well with regular morphology and with other syntactic tests (summarized here and in section 1.5.3), Clahsen and Almazan concluded that the computational system, is intact in this disorder.

7 e.g. Experimenter "Today I shrim, yesterday I...?"

Participant "shrim."

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One study conducted by Karmiloff-Smith et al. (1997) has played a prominent role in arguments about whether morphosyntactic rules are intact or not in WS. These authors reported problems with grammatical gender in 14 French WS individuals (age 9 to 22). This group differed from normally-developing children (age 4;6 to 5; 11) in several ways.

First, they were less able than controls to use a 100% reliable cue provided by the gender o f an indefinite article to extract the gender o f novel (pseudo-French) nouns. For example, the novel noun in the NP “un bicronne” must have masculine gender—the indefinite article definitively expresses that it does. But when an experimenter labels an object “un bicronne”, a WS individual may immediately refer back to the object with a feminine definite article, as in “la bicronne”.

Second, the WS participants were less able than controls to use probabilistic gender cues provided by the endings o f novel nouns to predict the probable gender o f those nouns. For example, the noun ending -ine is probablistically associated with feminine gender. When an experimenter labelled two nonsense objects “deux faldmes’”, the only clue to the gender o f the nonsense noun was this noun ending (the “deux” contains no gender information). WS children were completely at chance in whether they subsequently chose to express this nonsense noun along with a feminine definite determiner or a masculine one, while controls were significantly above chance.

These first two sets o f findings could be taken to reflect the same difficulty observed by Clahsen and Almazan (1998)— that is, difficulty in accessing rote-stored information. In fact Clahsen and Almazan analyze these results in this way. However, the third result from Karmiloff-Smith and colleagues provided perhaps the strongest argument that WS

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problems extend into an area that is more definitively “syntactic.” WS individuals were more likely than controls to produce noun phrases with a determiner and a color adjective whose gender endings did not match, as in “une ... gris”, which contains femininemarked article and a masculine-marked adjective. Even if children fail to access the correct gender o f a noun (either by extracting it from memory or by inferring it from the probablistic noun ending), they should at least make the determiner and the adjective agree w ith each other (as in “un ... gris” or “une ... grise”). Importantly, gender mismatches like this between the determiner and the adjective almost never occurred with known nouns (6%, which was not reliably different from the control rate o f 2%); they were confined to NPs containing nonsense nouns (37%, compared to the control rate o f 14%).

It is tem pting to conclude on the basis o f these results that this represents a syntactic violation. Levy and Hermon (2000) have made one argument against this conclusion which makes crucial reference to the fact that this lack o f gender concord was entirely restricted to NPs with nonsense nouns. These authors suggest that nonsense words have an “impoverished lexical status” that leads children to treat them differently from known lexical items. They argue that difficulty with tests involving nonsense items is commonly observed in both child and adult performance. A review o f pertinent past results is provided in an upcoming article by Levy and Tolchinsky (submitted). Support for this idea comes from the Karmiloff-Smith study itself: the control children also made more gender mismatch errors with nonsense nouns than they did with known nouns (14% vs. 2%). Thus, a particular difficulty with nonsense nouns is not an abnormal result.

Clahsen and Almazan also criticize a “syntactic deficit” interpretation o f the gender

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mismatch results, and their argument is also based on the fact that the gender mismatch occurred only with the nonsense nouns. The good results with known nouns is the most convincing aspect o f the results for them. They argue that “ ...full NPs with articles, nouns and adjectives are unlikely to be stored unanalysed in memory. Therefore, the relatively well preserved performance on these NPs shows that the morphosyntactic rules governing gender concord in French must be available to the WS subjects in the same way as to the unimpaired controls” (p. 171—172).

In light o f these many concerns about the interpretation o f the gender mismatch errors in the Karmiloff-Smith et al. (1997) study, I think that more evidence is called for regarding the evaluation o f morphosyntactic rule use in WS. I have chosen to examine adherence to a constraint on the form o f synthetic noun-noun compounds like rat-eater. This constraint does not require children to retrieve rote-memorized inflected forms o f words, but rather requires children to selectively suppress rule-derived inflected forms o f words that they have just produced. This study is reported in chapter 2.

The errors reported in this section suggest difficulty in lexical access in WS individuals. These results form part o f a growing body o f research suggesting a variety o f lexical anomalies and deficits in WS language. This research is summarized in the next section.

1.5.6 Lexical Anomalies Stevens and Karmiloff-Smith (1997) have demonstrated that WS individuals do not exhibit the same behavior as normally-developing children in the area o f word learning. These authors showed that a group o f 11 WS individuals (age 8—31) did pattern like

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normal children in two areas, but did not pattern like normal children in two other areas. The WS group did abide by the mutual exclusivity constraint—they show ed the normal expectation that an object should, have just one name (Markman and Waclhtel, 1988). And they did show the normal expectation that a novel word should map ontto an object that they do not already have a name for (the “Novel Name—Nameless C ategory Principle”; Golinkoff, Mervis, and Hirsh-Pasek, 1994; Mervis and Bertrand, 1994).

However, they did not abide by the whole object constraint or the taxonom ic constraint. That is, they did not show the normal expectation that a name applied t o a novel object will refer to the whole object as opposed to its parts or features (M arkm an and Wachtel, 1988). Similarly, when they were given a novel name (X) for a novel object, and then asked for another X, they did not show the normal bias to choose an o b ject from the same taxonomic category (another novel animal) rather than an object w itli shared visual features but from another category or a thematically related object (e.g. do*g, bone).

Despite this difference in patterns o f lexical learning constraints, WS individuals have a surprisingly good vocabulary. Although vocabulary rarely reaches cturonological age level, it has been reported to surpass MA level (Mervis et al, 1999). -Although some studies fail to report a vocabulary advantage (e.g. Volterra et al., 1996), the discrepancy across studies may reflect the early language delay characteristic o f WS and/or the different ages o f individuals tested (cf. discussion o f the faster rate o f «ievelopment of verbal abilities than nonverbal abilities in section 1.5.2).

In fact, Bellugi et al. (2000) report that since their earliest studies with W"S individuals in the late 80’s, they have noticed that WS speech is peppered with low-firequency words

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like ibex, evacuate, etc, and that on word fluency tests where people are asked to name all o f the animals they can think of, WS individuals seem to produce a greater proportion o f low frequency words than other children with the same MA (both Down syndrome and non-disordered children). Bellugi and colleagues have taken this to indicate that WS individuals show an attenuation o f frequency effects that others are normally sensitive to, perhaps suggesting “anomalous semantic organization” (Bellugi et al. 2000, p. 14).

Although others have tried and failed to replicate the pattern o f high rates o f lowfrequency words with word fluency tests (Johnson & Carey, 1998, Scott, Mervis, Bertrand, Klein, Armstrong, and Ford, 1994; Volterra et al., 1996), there remains some evidence for anomaly in this domain. For example, as we saw in section 1.4.6, word span capacity among WS children is not affected in the normal way by word frequency (Vicari et al., 1996). Additionally, Bellugi et al. (2000) report that on tasks investigating the processing o f homonyms, WS individuals seem to process both the primary (higher frequency) and secondary (lower frequency) m eanings o f homonyms w ith equal facility—whereas Down syndrome and normally-developing children of the same MA show an asymmetric advantage for primary meanings.

Additional findings suggesting lexical difficulties come from studies documenting word finding difficulties. For example, in a longitudinal case study, one Italian child with WS (age 3—4) was reported to make frequent semantically-related substitutions in object naming. For example, she sometimes used the (Italian) word brush when she intended comb. Other confusions were substitutions o f chair for table, and flow er for leaf, etc. (Capirci, Sabbadini, and Volterra, 1996). Furtherm ore, many reports have now documented odd use o f spatial prepositions in WS (Rubba and Klima, 1991; Volterra,

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Capirci, Pezzini, Sabbadini, and Vicari, 1996; Landau and Zukowski, in press; Lichtenberger and Bellugi, 1998; Zukowski, Schwartz, and Landau, 1999). Given the widespread spatial cognitive deficits o f this population, however, it is likely that these errors at least in part are a reflection o f their spatial deficits.

Interestingly, no effect o f the lexical anomalies reported above was seen in a semantic priming study with 12 WS individuals (age 14—30) tested by Tyler, Karmiloff-Smith, Voice, Stevens, Grant, Udwin, Davies, and Howlin (1997). Priming studies are difficult to conduct with this population, because many procedures (e.g. lexical decision, pronunciation) tend to use visual presentation o f words, and reading is delayed and difficult for many WS individuals, even into adulthood (Howlin, Davies, and Udwin, 1998). Nevertheless, it was found that an auditory word monitoring procedure was possible, and this was used to test automatic semantic processing in this group. The authors reported that their WS group showed an age-appropriate normal pattern o f prim ing for both functionally related and taxonomically related prim e-target pairs, suggesting normal semantic organization. How these findings can be reconciled with the behavioral findings discussed above has yet to be determined.

In sum, although the data are quite complicated and a fully coherent picture is still lacking, there is some evidence for lexical access problems—especially in the expressive language o f WS individuals.

1.5.7 Sensitivity to Syntactic Violations: Putting This to Good Use A number o f studies have now shown that WS individuals demonstrate sensitivity to

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syntactic violations. This sensitivity has been shown using a variety of experimental techniques. Bellugi et al. (1988) reported that WS adolescents were able to perform a grammaticality judgm ent task that included violations o f strict subcategorization features phrase structure rules, and number, gender, and/or person o f reflexive pronouns, and that they were able to correct the violations that were wrong. For example, when presented with the sentence “I hope you to eat all your supper”, one WS individual was reported to correct this to “I hope that you will eat all your supper” (Bellugi, Wang, and Jemigan, 1994, p. 30). Another WS individual corrected the sentence “The picture that painted the person was very kind” with “The picture that was painted by the man was very kind” (Bellugi et al., 1988, p. 189).

As we discussed above, Clahsen and Almazan (1998) showed that WS children respect Binding Conditions A and B when asked to tell whether a picture matches a spoken sentence containing a pronoun or reflexive. None o f the sentences in this test were ungrammatical in and o f themselves, rather they were ungrammatical on certain readings that were associated with some o f the pictures. Thus they showed sensitivity to the mismatch between certain form/meaning pairs.

Also, as we discussed above, Gage, Hickok, and Huntley-Fenner (submitted) demonstrated sensitivity to syntactic violations in a “plausibility judgment” task. These authors asked 2 WS adults to judge whether sentences were plausible or “silly, like something you m ight see in a cartoon”. These women were able to accurately reject sentences like “I saw a man who a dog walked” while accurately accepting sentences like “I saw a dog that a man walked”.

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Karmiloff-Smith and colleagues have even shown WS sensitivity to syntactic violations in an on-line processing study (Karmiloff-Smith, Tyler, Voice, Sims, Udwin, Howlin, and Davies, 1998). In a word monitoring task with a group o f WS individuals, sentences containing two types o f syntactic violations (word order violations and incorrect auxiliary verbs) interfered in the normal way with the ability to monitor the sentence for a target word (although in their study, a third type o f violation did not create a slow dow n with respect to grammatical counterpart sentences—violations of subcategorization).

Since individuals with WS show sensitivity to syntactic violations, and are even able to think metalinguistically about the meaning and form o f sentences, this is one strength in their skills that w e can and should capitalize on in evaluating their language competence. In particular, there are some aspects o f linguistic knowledge that are difficult to test with elicited production studies because it is too difficult to build up a context that uniquely calls for just the right structure. Grammaticality judgment tests offer a viable alternative in these cases.

In the last o f our four studies, I report a grammatical test that examines sensitivity to the contexts that license the use o f the negative polarity item (NPI) any and its positive counterpart some. This is another area that has never before been studied in W S, and it involves sophisticated semantic and pragmatic knowledge (cf. chapter 5). Furthermore, work by O ’Leary (1994) and O ’Leary and Crain (1994) has suggested that norm ally developing children exhibit some problems in this domain. For example, although they correctly avoid using the word any in illegal contexts without negation (e.g. *This sm urf got anything), they sometimes fail to use any when an adult would strongly prefer to use it (e.g. Where an adult would say “I don’t want any”, children are happy to say “I don’t

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want some”). This pattern has been exhibited by children as old as age 5. Thus, this study provides another opportunity for our WS group to surpass their MA-matches in a domain that is known to be difficult for unimpaired children. Furthermore, the range o f contexts that license negative polarity items varies tremendously in outward appearance, and I test a variety of these different contexts. This provides the opportunity for both groups o f children to show variability in whether they are sensitive to all o f the contexts or not. So again, we can determine whether the pattern o f sensitivity across contexts is similar between the two groups.

This concludes our review and discussion o f the past literature on language abilities in WS. Before moving on to the studies themselves, I will lay them out again in b rief outline, and discuss again what I hope to learn from them.

1.6 Overview of Four New Studies I have proposed four studies that are designed to reveal detailed information about the grammatical competence o f WS children for a wide range o f language abilities. The tasks are designed to reduce the possible confounding factors o f general intelligence and lexical access, and thereby provide a fairer assessment o f WS language competence (as WS individuals are impaired in both). Whether the WS group does poorly or well, the case will be made more convincingly, and the conclusions that we draw from WS about the modularity debate will be more solid.

Chapter 2 examines whether WS children are sensitive to the morphosyntactic constraint that disallows regular plural morphemes inside noun-noun compounds (e.g. *rats-eater)

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while at the same time allowing irregular plural morphemes inside compounds (e.g. miceeater). Chapter 3 examines the ability o f WS children to produce the full range o f embedded relative clause structure types that are included in comprehension tests that WS children often perform poorly on. Chapter 4 examines WS children’s knowledge about the grammatical form o f negative questions such as “W hat don’t you like?” Normally developing 3-5 year-olds frequently produce characteristic errors when they attempt such questions (e.g. “What do you don’t like?” and “W hat you don’t like?”) even though their affirmative questions are usually correct. And Chapter 5 tests knowledge o f various licensing contexts for the negative polarity item any and the positive polarity item some, using a grammaticality judgm ent format. Normally developing children produce ungrammatical uses o f some (e.g. *1 don’t want some) even though they show evidence o f knowing that some uses o f any are ungrammatical (e.g. *Every boy got any ice cream).

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2. Production of Synthetic Noun-Noun Compounds 2.1 Background and Motivation Adult speakers o f English share intuitions about what types o f inflected words may occur in compounds: someone who eats mice could be called a mice-eater, but someone who eats rats could not be called a rats-eater, they w ould have to be called a rat-eater. Kiparsky (1982) discussed an analysis o f word formation rules (an extension o f work by Allen, 1978 and Siegel, 1977) which provided a theoretical explanation for why adult speakers share these intuitions (and many others). According to this analysis, rules for word formation are ordered with respect to each other into three levels, at which different types o f rules apply. For example, host deforming types o f processes (e.g. mouse-^mice) occur at the earliest level, compounding (e.g. house+boat-^houseboat) occurs at a later level, and regular inflection (e.g. rat-^rats) occur at an even later level.

M ice-eater is well-formed, according to Kiparsky’s analysis, because the formation of mice occurs prior to compounding, and thus mice can be fed as input to the compounding rule. Rats-eater on the other hand is ill-formed, because the formation o f rats occurs after compounding, and thus rats cannot be fed as input to the compounding rule.

Gordon (1985) proposed that this level-ordering theory describes an innate structural property o f the lexicon, and that therefore children should show no evidence o f having to leam the constraints predicted to fall out o f it. He devised an elicited production study to determine whether children as young as 3 are sensitive to the compounding facts described above. He showed children toys whose names have either regular plurals (rats, hands) or irregular plurals (mice, feet), and showed that even as young as age 3 children

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almost never produce compounds containing regularly inflected plurals like rats-eater, but that as soon as children show any evidence o f knowing irregular plural forms like mice, they correctly allow them inside compounds, as predicted by Kiparsky’s model.

W hether Kiparsky’s model is an accurate characterization o f speaker intuitions about these compounding facts or not, the intuitions themselves are quite clear. There are several reasons why this study is particularly appropriate for exam ining sub-clausal morphology in WS. First, this domain o f linguistic knowledge does not entail lexical access— rather, it requires supression o f inflected forms that have ju st been accessed and produced (children must suppress the regularly-inflected form rats). Second, the task o f eliciting noun-noun compounds o f this kind from children requires the children to produce both regular and irregular plurals along the way. Thus, with this one task we can examine both irregular plural formation ability (which does require lexical access) and compound formation ability (which does not require lexical access).

I f WS children have intact word formation rules— or indeed i f they have whatever knowledge adult native speakers have regarding these kinds o f compounds— they should avoid forms like rats-eater all o f the time, and they should at least optionally allow forms like mice-eater.

2.2 Subjects The subjects included 12 WS children (age 8 to 16) and 12 typically-developing children (age 4 to 7). The WS children were participants in a long-term series o f studies o f spatial cognition and spatial language at the University o f Delaware. T hey were originally

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recruited from this study with the help o f the Williams Syndrome Association8. Families responded to letters requesting their participation. The control children were recruited from the laboratory preschool at the University o f Delaware, from several local Delaware chapters o f the Mom’s Club, and from a local church group.

Children from the two groups were paired up on the basis o f sim ilarity on the Kaufman B rief Intelligence Test (or KBIT; Kaufman & Kaufman, 1990). This test has two subtests: vocabulary and matrices (which includes non-verbal items testing reasoning and analogy skills). We matched children specifically on raw scores from the m atrices subtest, but because the children were participating in additional studies that also required them to be matched on vocabulary, in most cases individual WS-control pairs were also matched quite closely on vocabulary scores. Raw scores for these subtests for individual children are shown in Tables 2 and 3, and the average standard scores for the groups are shown in Table 4.

The WS children were also given two subtests o f the Differential Abilities Scale (DAS, Elliot, 1990): Block Construction, and Digit Recall. Age equivalences for these tests are also shown in Table 2. The scores obtained by the WS children o n these tests are typical for WS groups. Also included in Table 2 are scores for the WS children from the TROG, for comparison to previously reported WS groups.

The KBIT has a mean standard score o f 100 and a standard deviation o f 15. Since 95% of all individuals who take the test fall within 2 standard deviations above or below the mean, the average WS standard score for the matrices subtest (65.1) represents a score 8 Royal Oak, MI.

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lower than that attained by 97.5% o f individuals taking the test. The corresponding score for controls (108.3) suggests that our control group has slightly above average intelligence. Another important factor to bear in mind in comparing the standard scores (roughly speaking, the IQs) o f our WS group to others that have been reported (which tend to be lower than 65) is that the KBIT is particularly forgiving for WS people because unlike other intelligence tests commonly used, it does not test spatial construction skills. Further evidence that our WS group does not have an unusually high IQ compared to other WS groups comes from a direct comparison o f the K-BIT and the WTSC-III (Wechsler, 1991) with non-disordered children. The two tests were found to be highly correlated in a study o f 613 Polk County, Florida schoolchildren (age 6—15) who took both tests. The results revealed a Pearson r o f 73—88, depending on age (Boyd). But, importantly, children performed worse by an average o f 5.5 points on the WISC-III (full scale standard score) than on the KBIT (composite standard score). Table 2. Ages and Test Scores o f WS Participants DAS Block KBIT KBIT WS Vocab Construction Age Subject Age in Matrices Raw Equivalent Years Raw Score Score ID 15;0 5;4 1 24 46 10;5 5;7 2 22 27 3;7 3 11;3 21 40 10;0 5;4 4 21 32 14;2 5 20 31 4;1 14;0 6 19 35 4;1 7 10;5 30.5 18 3;l 10;4 8 17 42 4;1 4;4 9 11;8 17 23 12;8 3;4 10 16 40 16;3 4;10 11 14 31 8;4 12 13 26 possessor. The claim about universality is that in any language, i f one position on the hierarchy is relativizable, all positions to the left w ill also be relativizable. Since almost every child in the current study produced an OG relative at least once, there is no evidence that the children have misanalyzed the status o f English with respect to this hierarchy. However, it may be the case that the crosslinguistic generalization itself follows from differences in processing difficulty associated with the generation o f different relative clause types.

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Previous child production studies have also documented the difficulty o f OG relatives with respect to SG relatives. For example, Bar-Shalom, Crain, and Shankweiler (1993) elicited NPs containing relative clauses from thirty 7-8 year-olds who were either good or poor readers. Although both groups robustly produced SG relatives (over 68% o f the time, in SG trials), both groups were far less likely to produce OG relatives (no more than 37% o f the time, in OG trials). Furthermore, 2 children from each group failed to produce any OG relatives in their 12 opportunities each. Instead, they either produced SG relatives with passive verbs (e.g. The one who is being smacked) or they produced clausal modifiers with no object gap— that is, they filled the gap position with an overt element (e.g. The one that the cat is on it).

In adult research, the processing o f relative clauses has largely been confined to studies o f comprehension. An OG/SG as well as a center-embedded/right-branching asymmetry is a common finding in these studies. For example, Sheldon (1974) played taped sentences containing embedded relative clauses to adults, and immediately after each sentence asked them questions about who did what to whom in the two events encoded by the matrix and embedded clauses. Adults were asked to respond as quickly and accurately as possible. Sheldon found that when adults were questioned about the event that is encoded by the relative clause, they made more mistakes if the relative clause had an OG structure rather than an SG structure. And when adults were questioned about the event that is encoded by the m atrix clause, they made more errors with the centerembedded structures than with the right-branching structures. O f these two factors (gap position vs. embedding type), the one that led to highest rates o f errors was gap position. Similarly, in a reading study, Miyake, Carpenter, and Just (1994) revealed an OG/SG asymmetry in adult comprehension. Miyake and colleagues had adults read both right-

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branching and center-embedded OG and SG relatives under fast and slow rates o f wordby-word presentation. OG relatives yielded more comprehension errors than SG relatives, especially at rapid rates o f presentation, especially in center-embedded contexts, and especially for adults who achieved low scores on a standard test o f working memory capacity (Daneman and Carpenter, 1980).

Many researchers have proposed reasons for the greater difficulty adults have comprehending OG relatives than SG relatives. Caplan and Waters (1995, 1999) place the blame on the non-standard order o f thematic roles in OG relatives (patient agent action, as in the truck that the girl is jum ping over), which contrasts with the standard order observed in SG relatives (agent action patient, as in the girl that is jumping over the truck). Gibson (1998) proposes that the difficulty o f OG relatives in comprehension has to do with the distance between the head o f the relative and the gap position. The distance between the head and the gap is longer in OG relatives than in SG relatives, and there is more intervening material between the two positions in OG relatives. These factors increase the amount o f computational resources necessary for processing OG relatives compared to SG relatives.

These analyses all explain the difficulty o f OG relatives in terms o f difficulty in determining the intended meaning o f sentences being processed. In comprehension, this meaning can only be read o ff o f the structure. In production, the speaker knows the intended meaning o f the sentence under construction. It remains to be seen whether extensions o f these accounts o f the OG/SG comprehension asymmetry could be made to account for production asymmetries as well.

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However for our purposes, the important point is simply that an OG/SG asymmetry is amply demonstrated for non-disordered native-speakers of all ages, including normal adults. Thus, our replication o f this finding with both non-disordered children and WS children is not in the least surprising, and is not likely to reflect an abnormal language system in either group.

W hat do mapping errors reflect? Our results also revealed a mapping error that is not commonly reported in non-disordered language development— children sometimes produced a syntactically correct relative clause that failed to express their intended meaning. The mapping error w as robustly present in the responses o f both the WS group and the control group o f non-disordered 4—7-year-olds. The error also reflected an SG/OG asymmetry—it occurred almost exclusively in trials meant to elicit OG relatives. W hy has this error not been documented before? And what accounts for the error?

I f our results with unimpaired children are not anomalous, then given that the errors were fairly common (65 tokens in 480 OG contexts), it would be surprising if they had never been documented before. In fact, at least one study has reported a similar error. McKee, McDaniel, and Snedeker (1998) elicited relative clauses from norm ally developing 3year-old children. A small num ber o f errors that they report (which they classified as “head errors”) look precisely like the mapping errors that we documented. An example that the authors provided from one child (age 3;8) is given below, in the form o f a dialogue between the experim enter and the child (the experimenter’s speech is in parentheses). The target structure was The lemon that the sm urf is jum ping o n The wu—the boy who— dat's stomping on de lemon. {Oh, look careful, look careful!} (Should I pick up a boy or a lemon?) A lemon.

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115 (And which lemon should I pick up?) A boy dat— it—the boys that— the boy that's jumping on it. (OK; and should I pick up the lemon?) Yeah. (So which one? Cause there’s two lemons, right?) Yeah. (And which one should I pick up?) This one. (And which one is "this one"?) The...boy that's jumping on it.

This example is particularly striking because it shows how persistent the child was in sticking to this response.

Despite corroboration o f this error from the study by McKee and colleagues, it is still surprising how rarely mapping errors have been reported. One reason might be that they are more overtly inappropriate (and therefore m ore noticeable) when they occur embedded in a frill sentence than when they appear in NP only responses. In the example above {the boy th a t’s ju m p in g on it), the child could have intended an elided demonstratative {the boy th a t’s jum ping on it— that lemon). Since most relative clause elicitation studies elicit N P-only responses, there m ay sim ply have been few er opportunities to observe such errors in past work.

W hat m ight account for m apping errors? The best clue that we have to guide an explanation is that these errors were almost always confined to OG contexts, and they occurred across all three embedding contexts—right-branching, center-embedded, and NP-only. Thus, one easy but not very satisfying answer is that mapping errors are just another manifestation o f the difficulty o f OG relatives. This answer is unsatisfying because there is no explanatory link between the difficulty o f producing an OG relative and the fact that inappropriate SG relatives are produced in their place. Grammars would be very strange indeed if, whenever a difficult structure was called for, they substituted

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structures that are easier to produce without regard for the sem antics o f those substitutions.

A more explanatory account is suggested by the properties o f a prom inent model o f language production (Bock and Levelt, 1994). In this model there are three components which pass information from top to bottom: a message component, a grammatical component, and a phonological component. The model assumes that language production is incremental— that is, the components work simultaneously such that the speaker can begin pronouncing words at the start o f an utterance before she has actually planned the entirety o f the utterance. The grammatical component consists o f a variety o f sub­ operations. Important for our purposes is that this model makes a distinction between processes o f selecting lexical items and processes o f preparing portions o f hierarchical structure whose terminal nodes are initially not tied to particular lexical items. This dissociation between lexical selection and structure planning has long been thought by some to be required in order to explain speech errors or slips of the tongue. For example, it has long been known that word exchange speech errors usually preserve syntactic category, as the examples in (21)-{23) show.

21. Once I stop, I can’t start. (Dell, 1995) 22. Every time I put one o f these buttons off, another one comes on. (Dell, 1995) 23. Seymour sliced the knife with a salami. (Bock & Levelt, 1994) The way this model explains these errors is best illustrated with an excerpt from Bock and Levelt describing how it would account for (23): ...knife slipped into the noun slot in the direct object noun phrase in place o f sa la m i (perhaps because it was at that moment more activated). So far, this is sim ply a sort o f word substitution. But then, because knife was no longer available for the next noun slot, salam i was inserted in its stead to create a second error. Because insertion in the wrong syntactic slot is possible only i f the syntactic category o f the word is the same, word exchanges usually occur between words o f the same form class (over 80% o f the time;

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117 Garrett, 1980, Stemberger, 1985). (p. 956)

According to this model, errors o f production occur when a lexical item that has “been selected for use is inserted into the wrong position in a constituent structure whose l&asic skeleton has already been planned. The form o f the constituent structure that is plann.ed is influenced by multiple factors—the content o f the message that needs to be conveyed, the grammatical requirements o f the lexical items that have been chosen for use (Bockr and Levelt, 1994), recent priming o f the same structural form (Bock, 1986), and the ord-er in which lexical items become available (Bock, 1987; Ferreira, 1996).

A particularly interesting feature o f speech errors like the ones reported abowe is described in one sentence from the excerpt above: “because knife was no longer available for the next noun slot, salam i was inserted in its stead.” Speech errors like the o n e s in (21)-(23) suggest that speakers keep a tally o f which lexical items they have already slotted into position and pronounced and which ones are still waiting to be positioned! and pronounced. And they do not reuse an item which has already been used—even iff the first use was a mistake (although speakers m ay become conscious o f the word exchange in retrospect).

In sum, the speech errors made by non-disordered adults suggest that lexical ite m s are selected and buffered while pieces o f hierarchical structure are separately planned and buffered. How could a system like this account for mapping errors? A potentially meaningful clue is suggested by one unusual aspect o f these errors. In two thirds o f the conditioms in which mapping errors were produced, the head noun is the first part o f the tatrget response. For example, in the NP-only condition, the question is something like “wTiich

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truck turned red?”, and the target response begins “the truck th a t...” . Likewise, the question for the center-embedded condition is something like “which truck turned red and which truck turned blue?” and the target response begins in the same way (“the truck th a t...” In a mapping error, the child’s response to these “which tru ck ...?” questions begins with “the girl that...” To an adult ear, it is difficult to imagine how such errors could ever be made, since the first words that the child produces are already inconsistent with the question.

The fact that children produce the wrong lexical item in the head noun position o f the structure (even when this is the first portion o f the target response) seems to be important in understanding mapping errors because from the moment the wrong noun is placed in this position, the response is destined to be wrong. Since the child has already produced “the girl”, she will not use it again (exchange speech errors from adults suggest that this is likely to be the case). So the explanation o f why children make mapping errors may reduce to an explanation for why they produce the wrong head noun from the very beginning (the answer is likely to be the same for right-branching conditions, but it is simply more striking that children’s responses diverge from the target response so early in the production process in these other contexts).

W hy would children ever get the identity o f the head noun wrong when answering a question like “which truck...”? I think the answer concerns the fact that the head noun o f the target response is the “given” or “old” information in the discourse, while the new information that the child must supply is the information that will be mapped onto the clause embedded within the NP. Under these conditions, it may be the case that the child does not separately retrieve and prepare lexical material for the head noun position and

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for the clausal structure. I f they did, it would be extremely difficult to explain why children ever produce the wrong head noun. Rather, it may be the case that children only prepare the lexical material necessary for expressing the proposition that will be mapped onto the relative clause. But since the structure that they are planning is a noun plus a relative clause, they have to produce something in the head noun position. In the absence o f direct lexical retrieval o f material for that position, the only way in which that position can be filled is via an extraction o f one NP argument from the set o f arguments that are being prepared for mapping onto the relative clause.

I f it is correct that children draw material for the head noun position via extraction o f material planned for the relative clause, there is some scope for explaining why they get the head noun wrong sometimes— this occurs when they happen to extract the wrong noun. Why do they incorrectly extract the subject o f the planned relative clause so often? Perhaps because the lexical material that is planned for this position is available earlier in the production plan than the lexical material that is planned for the object position o f the relative. This would also account for why mapping errors are not observed in subject gap conditions—the lexical material that is planned for the object position o f the relative clause is simply not available early enough to be accidentally placed in the head noun positition in this case.

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W hy do WS children have more difficulty than controls with difficult OG relatives? Why do WS children show lower rates o f OG relative clause production than controls (despite knowledge o f how to produce them), and why they are more prone than controls to making mapping errors in OG contexts?

As we saw in the results, the very low rates of OG relatives for the WS group was not explained entirely on the basis o f the fact that they produced a lot o f (both appropriate and inappropriate) SG relatives in these conditions. There were even more “other” responses in the OG conditions than in the SG conditions (and this pattern was the same for the control children). Why do WS children produce OG relatives so rarely, given that they do know how to produce them? A wealth o f findings in child and adult language research suggest that an OG structure is simply more difficult (to both comprehend and produce) than an SG structure. It is likely that the answer to why this structure is particularly difficult for WS children will have to await the answer to why it is difficult for everyone else.

The analysis that was proposed for children’s mapping errors offers several suggestions for why it might be the case that WS children make these errors more often than younger unimpaired children. Since WS children have lexical access problems, their retrieval o f the lexical material that is planned for the subject and object position o f the relative clause may be slower than that o f control children. Because o f the incremental nature o f the production process, the preparation o f material for the subject position will likely precede the preparation o f material for the object position. Unimpaired children may have m aterial for both positions available at the time they begin their response, while WS children may only have the material for the subject position ready when they begin their

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response. Thus, the children all have equal opportunities for incorrectly extracting the subject material for the head noun position, but the unimpaired children may have an advantage in having greater opportunity for correctly extracting the object material.

3.5.4 Conclusion

Despite low rates o f production o f some kinds o f difficult relative clause structures by WS children, and despite susceptibility to making mapping errors, our results strongly suggest that knowledge o f relative clauses in WS is not qualitatively different from nondisordered language. None o f the problems that were observed among the WS children were across-the-board problems. T hey were always asymmetric, always in the direction that is reasonable and expected on the basis o f adult processing research, and always matched by similar problems am ong control children o f similar MA. Furthermore, we observed a strong trial-by-trial correlation between mapping errors in the WS and control groups. This correlation suggests that factors having to do with the interpretation and processing of the events depicted in the base pictures are responsible for misleading the process o f language production. W hatever the nature o f these factors, the important clue for characterizing WS language is the similarity itself. W hatever the factors are, the correlation suggests that they are the same for normally-developing children as for WS children. This we will have to leave for future research.

In the two chapters that follow, w e turn to an examination o f WS linguistic abilities about which nothing has been reported in the past: the production o f yes/no and wh-questions and the licensing o f the polarity sensitive expressions any. and some. In both o f these domains, we know from past research that unimpaired 5-year-old children do not yet

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completely resemble adults in their production patterns. These studies therefore provide an opportunity for us to see whether the WS children surpass their non-disordered MAmatches in these late-developing domains, and i f they do not, to examine whether they demonstrate the same pattern o f performance and errors as non-disordered children.

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4. Production of Negative Questions 4.1 Background and Motivation One area o f non-disordered grammatical development that appears relatively protracted involves the production o f negative questions. Bellugi (1965) noted that subject auxiliary inversion (which I will call auxiliary raising) seems to develop piecemeal in children’s speech. It appears first in yes/no questions (e.g. Do you want some?), and only later is extended to Wh-questions (e.g. What do you like?). Bellugi (1971) later showed that even after auxiliary raising is consistently done correctly in affirmative questions like the examples above, children continue to resist auxiliary raising in negative questions for some time (e.g. they might say What you don’t like? instead of What don ’ty o u like? ).

Guided by these observations from children’s spontaneous speech, Thornton (1993) documented these errors more systematically by using an elicited production technique ■with children age 4;3—5;0 years. She confirmed the affirmative/negative asymmetry that Bellugi had found, and catalogued a large corpus of children’s attempted negative questions. Her results revealed that in addition to simply failing to raise the auxiliary in negative questions (e.g. Why you d o n ’t like cheese?), children sometimes also doubled the auxiliary (e.g. What do you d o n ’t like?) and sometimes produced questions that raised the auxiliary but left the negative behind (e.g. What do you not like?), a grammatical alternative to structures like What do n 't you like? What this range o f responses has in common is not difficulty in auxiliary raising, but rather difficulty in raising negation. Thus Thornton proposed that children’s production o f ungrammatical questions like What you d o n ’t like? is not due to a lack o f question formation competence, but rather reflects other properties that conspire to disfavor negation raising in questions (Thornton’s

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analysis is discussed in section 4.5).

Thornton’s (1993) results have been replicated in subsequent studies with other children in a sim ilar age range (Thornton, 1994; Guasti, Thornton, and W exler, 1995). One additional clue to the nature o f the problem is provided in the Guasti, Thornton, and W exler paper: the individual results given there show that despite low rates o f negation raising in 10 children, 7 o f them do raise negation at least once in their corpus o f negative questions (out of an average o f 41 negative questions produced per child). We will discuss analyses of these patterns in section 4.5.

Our third study adopts a modified version o f Thornton’s procedure to elicit both positive and negative questions from WS children and controls. It is not known how late this pattern o f ungrammatical negative questions persists in normal development, because children beyond about age 5;0 have not been tested. Half o f our controls are in the same age range as the participants in Thornton’s studies, so we expect that at least some of these children will demonstrate the problems with negation raising discussed above. The performance o f the other half o f our controls will demonstrate whether these problems can normally extend later than age 5;0. Crucially, for the purposes o f understanding language abilities in WS, we are interested to know whether our WS group surpasses their MA-matches in their ability to produce adultlike negative questions. If they do not, we are interested to know whether the pattern o f non-adult forms is similar for the two groups.

Before we move on to a description o f our study, we will briefly remind the reader o f the basic facts about question formation in English, which we will describe in a relatively

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pre-theoretic way. The relevant facts are:

1. Questions require a tensed auxiliary or modal verb to appear immediately before the subject NP. 2. A dummy auxiliary do can fulfill this requirement i f a sentence contains no other auxiliary or modal. 3. A n inflected auxiliary or m odal in pre-subject position cannot co-occur with an inflected auxiliary or modal in declarative (post-subject) position. 4. In negative questions, the negation may occur cliticized to the auxiliary in pre-subject position, or it may remain in declarative position in its full form (i.e. not).

First, although auxiliaries (and modals) in declaratives appear between the NP subject and the main verb (e.g. I can go), they must appear in a different position in questions: immediately prior to the NP subject (e.g. Can I go?). This positional change in questions is traditionally referred to as NP-auxiliary inversion or auxiliary raising (we adopt the latter term )18. This requirement holds for all yes/no and wh-questions, regardless o f whether they are affirmative or negative. Second, if the declarative correlate o f a given question does not contain an auxiliary or modal (e.g. Chris likes mudpies), then in order to fulfill the requirement in (1), the question form m ust contain a dummy auxiliary in the pre-subject position (e.g. Does Chris like mudpies?). The auxiliary used in English for this purpose is do, and its insertion to fulfill this and other purely grammatical requirements is traditionally referred to as do-support. Third, an inflected auxiliary (or modal) cannot simultaneously occur in both pre-subject position and post-subject position

18 In later Chomskyan work, this positional change was conceived o f as the movement o f the contents o f the Inflection (I) head into the Complementizer (C) head.

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in questions (e.g. * When can we can go?), even though we intuitively understand that each question (e.g. When can we go?) is naturally related to a set o f declaratives with the auxiliary in the post-subject position (e.g. We can go tomorrow/Wednesday/now). And finally, clausal negation may invert along with the auxiliary in questions, but only i f it is cliticized to the auxiliary (e.g. When c a n ’t you go?), not if it appears in full form (e.g. the Shakespearean-sounding *When cannot y o u go?). H ow ever, negatio n is not grammatically required to raise in this way (e.g. it is fine to say When can yo u not go?)', when it does not, it must occur in its full form (e.g. *When can you 'nt go?).

W ith this background in mind, we now turn to our elicited production study o f question formation in WS.

4.2 Subjects The same 12 WS children and 12 controls that were tested in the noun compounding study were tested here (refer to section 2.2 for the details).

4.3 Method Thornton (1993) elicited questions from children as young as age 3;8. She did so by engaging them in a game in which they addressed questions to a puppet who was “too shy to talk to grownups”. The young age o f the children in Thornton’s study restricted the length of their testing sessions, so a corpus o f questions was collected over 3 or 4 sessions for each child. The challenge for the study we report here was to devise a task that would be engaging and fun for children from age 4 to 16, and if possible, one that would elicit a large number o f questions in one testing session. Furthermore, the task had

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to provide a compelling and natural reason why it had to be the children who addressed the questions rather than the experimenter. W e managed to achieve all o f these things by staging a mock telephone interview, which is described in greater detail below.

4.3.1 Materials 50 target questions were created, along with protocols that were designed to lead children to produce exactly those questions. The questions were o f 5 types (with 10 tokens each), illustrated in the 5 filled cells o f Table 27.19 The complete set o f target questions is given in Appendix F. Within each condition a variety o f auxiliaries and modals were used (can, could, and a variety o f inflected forms o f do), and within each Wh-condition, a variety o f Wh-words were used (who and what for the Wh-object questions, and why, where, and when for the Wh-adjunct questions). This variety o f wh-words was included because Thornton (1993) reported that some children consistently produce a different non-adult form for different wh-words. The auxiliary and wh-word variations in our materials were largely balanced across the affirmative and negative target questions (as Appendix F shows).

Table 27. Samipie Target Questions in Negative Question Study Negative Affirmative — Yes/No Do you like hamburgers? Wh-Object What flavor don’t you like? What kind o f pets do you have? Wh-Adjunct Where does your tarantula sleep? Where don’t you want to live?

19 We did not include negative yes/no questions (e.g. D on’t you like pizza?) because it proved extremely difficult to design contexts that make them uniquely felicitous. W e also excluded Wh-subject questions, either positive or negative, because the gap in subject position makes it impossible to tell whether raising o f the auxiliary or negation has occurred (e.g. In a subject question like Who didn't go to the movie?, the gap corresponding to the original position o f the who could be before the didn’t or after it). A second problem with subject Wh-questions is that when they are affirmative they do not require do-support (e.g. Who went to the movie?), and thus do not provide an ideal control for comparison to their negative counterparts.

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The protocols that were designed to elicit the example questions in Table 27 are shown in Table 28. The general form o f these protocols was modeled after those designed by Thornton (1993). Several points about protocol design are necessary. One anticipates a potential criticism that the experimenter’s speech influenced children’s responses. The other explains the peculiar set o f features that had to be supplied by the interview discourse in order to make negative questions uniquely felicitous.

Table 28. Samipie Protocols in Negative Question Stuc ly Affirmative Negative I wonder if she likes hamburgers. — Yes/No Ask her for me. I don’t know what kind o f pets she She doesn’t like one flavor?? Ask Wh-Object her what flavor. has. Ask her what kind. I heard that there’s one place she Wh-Adjunct I wonder where the tarantula sleeps. doesn’t want to live. Ask her Ask her where. where. Protocols sometimes contained embedded forms o f the target questions ( / wonder i f she likes hamburgers), and sometimes declarative forms or forms with declarative word order (e.g. the echo question She doesn't like one flavor??? and the declarative I heard that there’s one place she doesn't want to live). As the examples illustrate, all o f the protocols contained either an uninverted auxiliary or modal or none at all. Furthermore, when a protocol contained a negation, it always appeared cliticized to an auxiliary. In other words, the protocols contain no models o f questions with auxiliary inversion, and no models with the negation separated from the auxiliary.

Thus, if a child’s productions are influenced in a simplistic way by the experimenter’s lead-ins, their elicited questions would contain either uninverted auxiliaries (no auxiliary raising) or none at all (e.g. no do-support), and/or their negatives (whether raised or not)

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would appear cliticized to the auxiliary, rather than appearing in full form separated from the auxiliary. Since none o f the protocols for any question type modeled auxiliary inversion, any influence this may have had should be equally distributed across all types o f elicited questions.

T hornton’s (1993) success in eliciting negative questions from young children was an impressive methodological achievement. The difficulty in designing protocols that are uniquely felicitous for negative Wh-question responses can best be seen by contrasting the conditions under which one could ask (A) versus (B). A. W here do you ride your bike? B. W here don’t you ride your bike? Question X can be asked equally felicitously whether the listener rides her bike in just one place, in many places, or not at all— a perfectly acceptable answer would be “I don’t ride m y bike at all”. By comparison, question Y can only felicitously be asked when a tightly restricted set of presuppositions are met. Question Y presupposes both that there are places that the listener does ride her bike, and that there are places that the listener does not ride her bike. So the question is only felicitous if one has established both o f these presuppositions in the prior discourse. These presuppositions were often built up w ithin the interview bit by bit. For example, a child might first be led to ask w hat the interviewee likes to do on the weekends. The interviewee’s planned response would be “I like to ride m y bike a lot”. The child would then be prompted to ask w h e re the interviewee likes to ride her bike (yielding an affirmative Wh-question). Then the child would repeat the interviewee’s answers to the experimenter (who is not on the phone and thus cannot hear the answers). Finally, the child would be told “But I heard that there’s one place that she doesn ’t ride her bike. A sk her where.” At this point, all o f the

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presuppositions necessary for the target question (Where don’t you ride your bike?) are satisfied, and under these rather complicated conditions, negative Wh-questions seem fairly natural.

Several different methods o f satisfying the necessary presuppositions for negative Whquestions were used. In addition to the one illustrated above, another common strategy was the use o f contrastive focus. For example, in one case the interviewee told the child that while on her vacation, she visited her cousins. When the child repeated this to the experimenter, the very next prompt was “Hey—I heard that there’s ONE COUSIN that she doesn’t like. Ask her which one.” This prompt simultaneously asserts the necessary negative proposition (she doesn’t like one cousin) and implicates the necessary contrasting affirmative proposition (she does like some cousins).

As the examples illustrate, following certain themes in the interview was necessary, both to m ake the interview seem more natural, and to establish the very precise discourse conditions for eliciting certain question types. Thus, the 50 questions related to 7 topics that were introduced into the interview. The topics that were covered concerned the interviewee’s last birthday party, their last vacation, their pets, their bedtime, where they live, their food preferences, and what they like to do on weekends. Each of the topics included different numbers and different types o f target questions. W ithin a single topic, the question order always rem ained the same. This was necessary because (as the examples above illustrate) many o f the questions built upon the answers to the previous ones. To balance out the ordering effect that these inherent differences among the topics would have otherwise created, 3 orders o f topic blocks were created. The blocks were scrambled in such a way that in each o f the 3 orders, by the time a child had finished the

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first 25—30 trials (roughly halfway through the test), they had finished roughly h alf o f the 10 trials from each o f the 5 conditions (specifically 4, 5, or 6 trials). Each control child received the same order as his or her matched WS child.

4.3.2 Procedure

The task was introduced to the children as a game in which the child would conduct a telephone interview with someone pretending to be a celebrity. The “celebrity” was an accomplice o f the experimenter who was waiting by a phone somewhere for the child’s call. For many o f the younger children, the accomplice was another adult from the lab, who the child already knew, and the child watched him or her walk to an adjacent room to wait for the phone call. This made the phone call less intimidating for some children. Children were encouraged to choose for themselves who the person should pretend to be. Their choice made no difference to which target questions we attempted to elicit. The experimenter pretended to be a reporter for the New York Times, and fed questions to the child from a clipboard. The child conducted the whole interview by “passing on” the questions that the experimenter fed her, and repeating the replies to the experimenter, who pretended to write them down. The telephone conversation was tape-recorded with a phone-recording device, but while the interview was taking place, only the child (who was holding the phone) was able to hear the “celebrity’s” responses.

The “celebrity” had a script which contained the experimenter’s lead-ins, the target questions, and the answers they were to provide. Their scripted responses never contained questions which modeled auxiliary raising. Often the celebrity’s answers provided the background for subsequent questions, as described above, and as further illustrated in the

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exchange below. Experimenter I wanted to ask Elvis about his vacation this year, but actually I don’t know if he got a vacation. Ask him if he did. WS child: Did you have a nice vacation? Elvis: Oh yeah it was excellent. Experimenter Oh I wonder who he visited, ask him who. WS child: Who did you visit? Elvis: I visited my cousins. Experimenter You know what, I heard that there’s one cousin that he doesn’t like. Ask him which one. WS child: Which one don’t you like? Elvis: I don’t like Bob. Experimenter He doesn’t like Bob? Ask him why. WS child: Why? Elvis: Why what? WS child: Why don’t you like Bob? Elvis: Because I have to share a room with him, and he snores.

One problem that we encountered (and its solution) is shown in the fourth line from the bottom o f this excerpt. Often children would ask a truncated question like “Why?” Such a shortening is quite natural in the context o f a few o f the exchanges, as the example shows. The solution that we settled on was to have the celebrity feign forgetfulness by asking “W hy what?” This nearly always led to an attempt at a fuller version o f the question.

4.4 Results All 12 o f the WS children were able to complete the task, however several o f the original control children had to be coaxed considerably into overcoming their shyness o f talking on the telephone. One control child completely refused (control subject 11), and we were not able to replace him in the study, so we have left out the data from his matched WS participant (WS subject 11)20. Thus, we describe here the results from 11 children from each group. 20 The responses from the WS subject that w e left out fall squarely in line with those exhibited by most o f the other children tested, both WS and controls: near perfect target questions with affirmative questions o f all kinds, but avoidance o f the raising o f negation in negative questions.

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Most o f the children thoroughly enjoyed the game, and the experimenter learned a good deal about popular culture from their choice of celebrities. Children interviewed Mia Hamm (a member o f the U.S. wom en’s soccer team), Britney Spears, members o f N Sync and the Backstreet Boys, Leonardo di Caprio, Elvis, John Lennon, Bill Clinton, George Washington, the Tin Man, Goldilocks, Dopey (of the 7 Dwarves), and Miss Linda (who works at Dunkin Donuts).

4.4.1 Success of the Methodology

First, as a gauge o f the success o f the methodology, we examined how often children attempted to produce a question o f approximately the intended target type (e.g. how often they produced a negative object question o f some kind when one was targeted, etc.) We leave out o f this count trials in which the child’s question was a partial repetition of the experim enter’s lead-in (e.g. Experim enter says “there’s one flavor that he doesn’t like— ask him which flavor”, and child says “what flavor that you don’t like?”). These responses were occasionally made by children from both groups, but not especially more with one group than the other.

The methodology proved quite good at eliciting the intended question types—WS children attempted the right type o f question on average 86% o f the time, and the average for controls was 91%. We also examined the remainder o f the questions from each group (14% for WS 9% for controls) to see whether negative questions were over-represented among them—we reasoned that one way children might deal with difficulty in forming negative questions would be to simply avoid producing them. The result was that they did not. Negative questions trials made up 40% o f the test questions, and on average, 43% of

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the WS children’s non-target alternative questions came from negative question trials, while this average was 52% for controls. So there is no evidence that the children were especially avoiding producing negative questions.

4.4.2 Overview o f the Results

Both groups o f children produced examples o f each type o f question structure documented by Thornton (1993) and Guasti, Thornton, and Wexler (1995). Examples o f each type are given below. Target Questions Yes/no: Did you see any movies on your vacation? (WS #2) Positive Wh: What kind of pets do you have? (WS #8) Negative Wh: Why don’t you kiss your tarantula? (WS #4) No Auxiliary Raising Yes/no: You saw any movies? (WS #5) Positive Wh: What kind o f pets you got? (WS #5) Negative Wh: Why you didn’t kiss your tarantula? (WS #5) Why you don’t like Bob? (Control #2) Double Auxiliary Yes/no: Did you did see any movies? (not attested) Positive Wh: What kind of pets do you do have? (not attested) Negative Wh: Where can your dogs can’t sleep? (WS #1) What place do you don’t wanna live? (Control #7) “Not” Negative Wh: Where do you not wanna live? (WS #10) Why do you not kiss your tarantula? (Control #8) Neg Copy Negative Wh: Who didn’t you not invite? (WS #6) What flavor didn’t you didn’t like? (Control #7) A summary o f the results for each o f the question types for both groups is in Table 29.

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Table 29. All Questions: Average Percentage o f Various Structures Produced by Both Groups*________________________ __________________________________ _______ % o f all Responses M ean# of % Target No % % that Failed % Aux Double % Neg to Raise Questions Attempted Targets Raising Aux “Not” Copy Negation Positive Yes/No 95 5 0 — WS 9.3 (15.1) (15.1) (0) 100 0 0 Controls 9.5 (0) (0) (0) Positive Wh-Questions WS

16.8

Controls

17.7

86 (29.9) 99 (2.4)

14 (29.9) 1 (2.4)

45 (34.4) 47 (39.8)

31 (38.5) 9 (22.1)

0 (0) 0 (0)

—

Negative Wh-Questions WS Controls

16 16.7

11 12 1 (17.6) (25.1) (2.5) 18 24 2 (24.2) (34.8) (4.1)

54 51

♦Standard deviation is shown in parentheses

Target responses in Table 29 refer to those that take the form shown in Table 27— that is, questions that exhibit raising o f both the auxiliary and—if it is a negative question—the negation, above the subject NP. All o f the other responses in Table 29 are characterized by lack o f raising o f either the auxiliary or the negative o r both. In addition to these basic response types, the final column of Table 29 sums up the three categories o f responses that have in common the property that negation fails to raise above the subject (i.e. the categories o f “No Aux Raising3’, “Double Aux” and “Not”).

Overall, the pattern o f responses for the two groups is remarkably similar. We will organize the discussion o f group similarities and differences around five different measures: rates o f production o f target structures, range o f non-target response types, rates o f all responses that failed to raise negation, rates o f no auxiliary raising, and rates

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o f all responses that were ungrammatical.

4.4.3 Group Data

Rates o f target responses. Table 29 shows that rates o f target question structures are highest for both groups o f children for positive yes/no and positive Wh-questions (86% and above), and much lower for negative W h-questions (around 46%). T his was confirmed by a 2-way (group X question condition) analysis o f variance, F(2,60)=27.5, p