Syntax and morphology in Williams syndrome

Language and Communication Deficits in Chromosome 16p11.2 Deletion Syndrome

PURPOSE

Chromosome 16p11.2 deletion syndrome (OMIM #611913) is a rare genetic condition resulting from the partial deletion of approximately 35 genes located at Chromosome 16. Affected people exhibit a variable clinical profile, featuring mild dysmorphisms, motor problems, developmental delay, mild intellectual disability (ID), socialization deficits and/or autism spectrum disorder (ASD) traits, and problems with language. Specifically, a precise characterization of the speech, language, and communication (dis)abilities of people with this condition is still pending.

METHOD

We used standardized tests and samples of naturalistic speech to provide a longitudinal profile of the speech, language, and communication problems of a boy with Chromosome 16p11.2 deletion syndrome and without ID or ASD.

RESULTS

The proband shows impaired expressive abilities as well as problems with receptive language, dysprosody, and ASD-like communication deficits, such as impaired interactive skills, perseverative verbal behavior, overabundance of tangential responses, and lack of metapragmatic awareness and communicative use of gaze, meeting the criteria for social pragmatic communication disorder.

CONCLUSIONS

Our results support the view that language and communication impairment should be regarded as one core symptom of Chromosome 16p11.2 deletion syndrome, even without a diagnosis of ASD or ID. Clinical implications of our results, with a focus on therapeutic interventions for children with 16p11.2 deletion syndrome and no ASD or ID, are also discussed.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21561714.

A meta-analysis of prosody in autism, Williams syndrome, and Down syndrome

Prosody, the rhythm and melody of speech, is an important component of effective communication, and it is an area of difficulty for many populations who struggle with communication. This paper is a meta-analysis of nine studies (and two sets of unpublished data) that assessed prosody using the Profiling Elements of Prosody in Speech-Communication (PEPS-C; Peppé & McCann, 2003) in autism spectrum disorder, Williams syndrome, and Down syndrome. Our original goal was to include studies involving any neurodevelopmental disorder that is commonly associated with intellectual disability, yet our systematic search, which included three databases (i.e., PsychInfo, ERIC, and PubMed), only identified studies involving these three groups. To be included in the meta-analysis, studies had to include a group (n ≥ 3 participants) with a neurodevelopmental disorder commonly associated with intellectual disability and a typically developing comparison group matched on chronological age, nonverbal abilities, or verbal abilities. Studies also needed to report original data using the PEPS-C and be available in English. Study quality was assessed using a checklist adapted from Downes et al. (2016). Results revealed that prosodic form was a weakness for each etiology, while unique patterns of strengths and weaknesses were evident for prosodic functions. Groups with autism (n = 5), all classified as high-functioning or with Asperger's syndrome, exhibited weakness in emotional affect but some relative strengths with turn-end and focus tasks. Groups with Williams syndrome (n = 4) demonstrated weaknesses on phrase/sentence-level tasks and relative strengths on word-level tasks. Groups with Down syndrome (n = 2) had the greatest difficulty overall, though performance was better on receptive (vs. expressive) function tasks. By combining studies and related subtasks of the PEPS-C, we are able to more confidently generalize findings for each population and identify targets for intervention. However, given the limited number of studies identified, this paper also highlights the need for more research on prosody in intellectual disability.

Neurodevelopmental disorders

Recent technological advances allow us to measure how the infant brain functions in ways that were not possible just a decade ago. Although methodological advances are exciting, we must also consider how theories guide research: what we look for and how we explain what we find. Indeed, the ways in which research findings are interpreted affects the design of policies, educational practices, and interventions. Thus, the theoretical approaches adopted by scientists have a real impact on the lives of children with neurodevelopmental disorders (NDDs) and their families, as well as on the wider community. Here, we introduce and compare two theoretical approaches that are used to understand NDDs: the neuropsychological account and neuroconstructivism. We show how the former, adult account, is inadequate for explaining NDDs and illustrate this using the examples of Williams syndrome and specific language impairment. Neuroconstructivism, by contrast, focuses on the developing organism and is helping to change the way in which NDDs are investigated. Whereas neuropsychological static approaches assume that one or more 'modules' (e.g., visuospatial ability in Williams syndrome) are impaired while the rest of the system is spared (e.g., language in Williams syndrome), neuroconstructivism proposes that basic-level deficits have subtle cascading effects on numerous domains over development. Neuroconstructivism leads researchers to embrace complexity by establishing large research consortia to integrate findings at multiple levels (e.g., genetic, neural, cognitive, environmental) across developmental time. WIREs Cogn Sci 2017, 8:e1398. doi: 10.1002/wcs.1398 For further resources related to this article, please visit the WIREs website.

Syntax in Spanish-speaking children with Williams syndrome

The syntactic skills of Spanish-speaking children with Williams syndrome (WS) were assessed in different areas (phrase structure, recursion, and bound anaphora). Children were compared to typically-developing peers matched either in chronological age (CA-TD) or in verbal age (VA-TD). In all tasks children with WS performed significantly worse than CA-TD children, but similarly to VA-TD children. However, significant differences were observed in specific domains, particularly regarding sentences with cross-serial dependencies. At the same time, children with WS were less sensitive to syntactic constraints and exhibited a poorer knowledge of some functional words (specifically, of nonreflexive pronouns). A processing bottleneck or a computational constraint may account for this outcome.

French Williams syndrome's ability to produce judgments of grammaticality

This article reports grammatical judgment data from eighteen French Williams syndrome (WS) (mean CA = 21.10; Mean MA = 11.2). Participants had to detect ungrammatical sentences (13 amongst a set of 26 sentences) in telling whether a given sentence was well said or not. Agrammaticality could be due to errors in tense, person agreement, gender agreement, derivational or inflectional morphology, word order and so on. As a group, WS participants scored as seven-year-olds did, far below CA-controls and MA-controls. Scores did not improve with chronological age or mental age but they were related to total IQ and verbal IQ. They showed an important variability, one similar to what was observed in four-year-olds. Although a few WS individuals had good metasyntactic abilities, these abilities generally plateau in our WS group. They were not deviant, however, as the WS's profile of difficulties across items was qualitatively very similar to the one seen in seven-year-olds.

A dual comparative approach: integrating lines of evidence from human evolutionary neuroanatomy and neurodevelopmental disorders

The evolution of the human brain has been marked by a nearly 3-fold increase in size since our divergence from the last common ancestor shared with chimpanzees and bonobos. Despite increased interest in comparative neuroanatomy and phylogenetic methods, relatively little is known regarding the effects that this enlargement has had on its internal organization, and how certain areas of the brain have differentially expanded over evolutionary time. Analyses of the microstructure of several regions of the human cortex and subcortical structures have demonstrated subtle changes at the cellular and molecular level, suggesting that the human brain is more than simply a 'scaled-up' primate brain. Ongoing research in comparative neuroanatomy has much to offer regarding our understanding of human brain evolution. Through analysis of the neuroanatomical phenotype at the level of reorganization in cytoarchitecture and cellular morphology, new data continue to highlight changes in cell density and organization associated with volumetric changes in discrete regions. An understanding of the functional significance of variation in neural circuitry can further be approached through studies of atypical human development. Many neurodevelopmental disorders cause disruption in systems associated with uniquely human features of cognition, including language and social cognition. Understanding the genetic and developmental mechanisms that underlie variation in the human cognitive phenotype can help to clarify the functional significance of interspecific variation. By uniting approaches from comparative neuroanatomy and neuropathology, insights can be gained that clarify trends in human evolution. Here, we explore these lines of evidence and their significance for understanding functional variation between species as well as within neuropathological variation in the human brain.

Space and language in Williams syndrome: insights from typical development

One of the holy grails of cognitive science is to understand the causal chain that links genes and cognition. Genetic syndromes accompanied by cognitive effects offer natural experiments that can uniquely inform our understanding of this chain. In this article, we discuss the case of Williams syndrome (WS), which is characterized by a set of missing genes on chromosome 7q11.23, and presents with a unique cognitive profile that includes severe spatial impairment along with strikingly fluent and well-structured language. An early inference from this profile was the idea that a small group of genes could directly target one cognitive system while leaving others unaffected. Recent evidence shows that this inference fails. First, the profile within the spatial domain is varied, with relative strength in some aspects of spatial representation but severe impairment in others. Second, some aspects of language may fail to develop fully, raising the question of how to compare the resilience and fragility of the two key cognitive domains in this syndrome. Third, much research on the profile fails to place findings in the context of typical developmental trajectories. We explore these points and propose a new hypothesis that explains the unusual WS cognitive profile by considering normal mechanisms of cognitive development that undergo change on an extremely prolonged timetable. This hypothesis places the elements of the WS cognitive profile in a new light, refocuses the discussion of the gene-cognition causal chain for WS and other disorders, and more generally, underlines the importance of understanding cognitive structure in both typical and atypical development. WIREs Cogn Sci 2013, 4:693-703. doi: 10.1002/wcs.1258 Conflict of interest: The authors have declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website.

Birth of an abstraction: a dynamical systems account of the discovery of an elsewhere principle in a category learning task

Human participants and recurrent ("connectionist") neural networks were both trained on a categorization system abstractly similar to natural language systems involving irregular ("strong") classes and a default class. Both the humans and the networks exhibited staged learning and a generalization pattern reminiscent of the Elsewhere Condition (Kiparsky, 1973). Previous connectionist accounts of related phenomena have often been vague about the nature of the networks' encoding systems. We analyzed our network using dynamical systems theory, revealing topological and geometric properties that can be directly compared with the mechanisms of non-connectionist, rule-based accounts. The results reveal that the networks "contain" structures related to mechanisms posited by rule-based models, partly vindicating the insights of these models. On the other hand, they support the one mechanism (OM), as opposed to the more than one mechanism (MOM), view of symbolic abstraction by showing how the appearance of MOM behavior can arise emergently from one underlying set of principles. The key new contribution of this study is to show that dynamical systems theory can allow us to explicitly characterize the relationship between the two perspectives in implemented models.

Comparison of Grammar in Neurodevelopmental Disorders: The Case of Binding in Williams Syndrome and Autism With and Without Language Impairment

This study investigates whether distinct neurodevelopmental disorders show distinct patterns of impairments in particular grammatical abilities and the relation of those grammatical patterns to general language delays and intellectual disabilities. We studied two disorders (autism and Williams syndrome [WS]) and two distinct properties (Principle A that governs reflexives and Principle B that, together with its associated pragmatic rule, governs pronouns) of the binding module of grammar. These properties are known to have markedly different courses of acquisition in typical development. We compare the knowledge of binding in children with autism with language impairment (ALI) and those with normal language (ALN) to that of children with WS, matched on age to the ALN group, and on age and nonverbal mental age (MA) to the ALI group, as well as to two groups of typically developing (TD) controls, matched on nonverbal MA to ALI and ALN groups. Our results reveal a remarkably different pattern of comprehension of personal pronouns and reflexives in ALI as opposed to ALN, WS, and two groups of TD controls. All five groups demonstrated an equal delay in their comprehension of personal pronouns, in line with widely reported delays in TD literature, argued to be due to delayed pragmatic abilities. However, and most strikingly, the ALI group also showed a pronounced difficulty in comprehension of reflexive pronouns, and particularly of the knowledge that the antecedent of a reflexive must c-command it. The revealed pattern confirms the existence of a particular impairment concerning Principle A in this module of grammar, unrelated to general language delays or cognitive deficits generally present in a large portion of individuals with autism as well as WS, or to general pragmatic deficits, known to be particularly prevalent in the population with autism.

Genes, language, and the nature of scientific explanations: the case of Williams syndrome

In this article, we discuss two experiments of nature and their implications for the sciences of the mind. The first, Williams syndrome, bears on one of cognitive science's holy grails: the possibility of unravelling the causal chain between genes and cognition. We sketch the outline of a general framework to study the relationship between genes and cognition, focusing as our case study on the development of language in individuals with Williams syndrome. Our approach emphasizes the role of three key ingredients: the need to specify a clear level of analysis, the need to provide a theoretical account of the relevant cognitive structure at that level, and the importance of the (typical) developmental process itself. The promise offered by the case of Williams syndrome has also given rise to two strongly conflicting theoretical approaches-modularity and neuroconstructivism-themselves offshoots of a perennial debate between nativism and empiricism. We apply our framework to explore the tension created by these two conflicting perspectives. To this end, we discuss a second experiment of nature, which allows us to compare the two competing perspectives in what comes close to a controlled experimental setting. From this comparison, we conclude that the "meaningful debate assumption", a widespread assumption suggesting that neuroconstructivism and modularity address the same questions and represent genuine theoretical alternatives, rests on a fallacy.

Analysis of speech fluency in Williams syndrome

Williams syndrome (WS) is a neurodevelopmental genetic disorder, often referred as being characterized by dissociation between verbal and non-verbal abilities, although the number of studies disputing this proposal is emerging. Indeed, although they have been traditionally reported as displaying increased speech fluency, this topic has not been fully addressed in research. In previous studies carried out with a small group of individuals with WS, we reported speech breakdowns during conversational and autobiographical narratives suggestive of language difficulties. In the current study, we characterized the speech fluency profile using an ecologically based measure--a narrative task (story generation) was collected from a group of individuals with WS (n = 30) and typically developing group (n = 39) matched in mental age. Oral narratives were elicited using a picture stimulus--the cookie theft picture from Boston Diagnosis Aphasia Test. All narratives were analyzed according to typology and frequency of fluency breakdowns (non-stuttered and stuttered disfluencies). Oral narratives in WS group differed from typically developing group, mainly due to a significant increase in the frequency of disfluencies, particularly in terms of hesitations, repetitions and pauses. This is the first evidence of disfluencies in WS using an ecologically based task (oral narrative task), suggesting that these speech disfluencies may represent a significant marker of language problems in WS.

The extent of working memory deficits associated with Williams syndrome: exploration of verbal and spatial domains and executively controlled processes

The present study investigated verbal and spatial working memory (WM) functioning in individuals with the neuro-developmental disorder Williams syndrome (WS) using WM component tasks. While there is strong evidence of WM impairments in WS, previous research has focused on short-term memory and has neglected assessment of executive components of WM. There is a particular lack of consensus concerning the profile of verbal WM functioning in WS. Here, WS participants were compared to typically developing participants matched for (1) verbal ability and (2) spatial ability (N=14 in each of the 3 groups). Individuals with WS were impaired on verbal WM tasks, both those involving short-term maintenance of information and executive manipulation, in comparison to verbal-matched controls. Surprisingly, individuals with WS were not impaired on a spatial task assessing short-term maintenance of information in memory (remembering spatial locations) compared to spatial-matched controls. They were, however, impaired on a spatial executive WM task requiring the manipulation of spatial information in memory. The present study suggests that individuals with WS show WM impairments that extend to both verbal and spatial domains, although spatial deficits are selective to executive aspects of WM function.

The perfective past tense in Greek adolescents with Down syndrome

This study investigates the ability of a group of eight Greek-speaking adolescents with Down Syndrome (DS) (aged 12.1-18.7) to handle the perfective past tense using an acceptability judgement task. The performance of the DS participants was compared with that of 16 typically-developing children whose chronological age was matched with the mental age of the DS group. For existing verbs, both groups showed high accuracy scores for the sigmatic past tense whilst for (potential but non-existing) nonce verbs the DS group performed differently from the controls. Specifically, their judgements were unaffected by a nonce verb's similarity to existing verbs, unlike those of the controls, suggesting that the DS participants were less reliant on similarity-based generalisations when encountering a nonce word than the controls. Apart from that, it was found that people with DS did not show any kind of morphological impairment, replicating previous findings on past tense production in DS.

Development of verbal passive in Williams syndrome

PURPOSE

To experimentally investigate knowledge of passives of actional (hold) and psychological (love) verbs in children with Williams syndrome (WS). Passives are usually reported to be in line with mental age in WS. However, studies usually focus on passives of actional verbs only.

METHOD

Twenty-six children with WS, ages 6-16, and 3 groups of typically developing controls, ages 3;6-14;4 (years;months), individually matched to the WS group on nonverbal reasoning, receptive vocabulary, or grammar, participated. Their comprehension of actives and short and long passives (with and without the by-phrase) was tested using a sentence-picture-matching task.

RESULTS

Children with WS performed well above chance on passives of actional verbs but extremely poorly on passives of psychological verbs (short and long). Furthermore, their performance on both types of passives was worse than that of matched controls.

CONCLUSIONS

The results reveal a previously unreported deficiency in the domain of syntax in WS, suggesting a particular difficulty with the structure of the verbal passive, not directly related to general levels of nonverbal abilities, receptive vocabulary, or general comprehension of grammar. It is argued that the difficulty in the formation of verbal passives in WS stems from a deficit in forming argument chains.

Uncovering Knowledge of Core Syntactic and Semantic Principles in Individuals With Williams Syndrome

We investigate knowledge of core syntactic and semantic principles in individuals with Williams Syndrome (WS). Our study focuses on the logico-syntactic properties of negation and disjunction (or) and tests knowledge of (a) core syntactic relations (scope and c-command), (b) core semantic relations (entailment relations and DeMorgan's laws of propositional logic), and (c) the relationship between (a) and (b). We examine the performance of individuals with WS, children matched for mental age (MA), and typical adult native speakers of English. Performance on all conditions suggests that knowledge of (a-c) is present and engaged in all three groups. Results also indicate slightly depressed performance on (c) for the WS group, compared to MA, consistent with limitation in processing resources. Implications of these results for competing accounts of language development in WS, as well as for the relevance of WS to the study of cognitive architecture and development are discussed.

Gender attribution and gender agreement in French Williams syndrome

Previous studies on grammatical gender in French individuals with Williams syndrome (WS) have led to conflicting findings and interpretations regarding keys abilities--gender attribution and gender agreement. New production data from a larger WS sample (N=24) showed that gender attribution scores in WS participants exactly mirrored those of controls: all groups overwhelmingly relied on the masculine as the default gender. WS participants' agreement scores were far lower than those of CA-controls though not significantly below those of MA-controls. They also did not improve with age, which might suggest a permanent disability in this area.

Using developmental trajectories to understand developmental disorders

PURPOSE

In this article, the authors present a tutorial on the use of developmental trajectories for studying language and cognitive impairments in developmental disorders and compare this method with the use of matching.

METHOD

The authors assess the strengths, limitations, and practical implications of each method. The contrast between the methodologies is highlighted using the example of developmental delay and the criteria used to distinguish delay from atypical development.

RESULTS

The authors argue for the utility of the trajectory approach, using illustrations from studies investigating language and cognitive impairments in individuals with Williams syndrome, Down syndrome, and autism spectrum disorder.

CONCLUSION

Two conclusions were reached: (a) An understanding of the underlying mechanism will be furthered by the richer descriptive vocabulary provided by the trajectories approach (e.g., in distinguishing different types of delay) and (b) an optimal design for studying developmental disorders is to combine initial cross-sectional designs with longitudinal follow-up.

Morphosyntax in children with word finding difficulties

Children with word finding difficulties (CwWFDs) are slower and less accurate at naming monomorphemic words than typically developing children (Dockrell, Messer & George, 2001), but their difficulty in naming morphologically complex words has not yet been investigated. One aim of this paper was to identify whether CwWFDs are similar to typically developing children at producing inflected (morphologically complex) words. A second aim was to investigate whether the dual-mechanism model could account for the use of morphology in a sample of CwWFDs, exemplifying the notion that regular inflections are part of a rule-based system and computed on-line, while irregular inflections are retrieved directly from the associative system (Pinker, 1999). The inflectional knowledge of a group of CwWFDs was compared against a group of language age-matched typically developing peers in three experiments. In Experiment 1 children produced the past tenses of high- and low-frequency regular and irregular English verbs. In Experiment 2 children generalized their knowledge of the past tense system onto nonsense verbs and in Experiment 3 children produced past tenses of verbs used in either a denominal or a verb root context. In each of these three studies, the CwWFDs performed similarly to matched typical children, suggesting that they do not have a selective problem with morphosyntactic features of words. The findings provide mixed support for the dual-mechanism model.

Research Review: Williams syndrome: a critical review of the cognitive, behavioral, and neuroanatomical phenotype

This review critically examines the research findings which characterize the cognitive, behavioral, and neuroanatomical features of Williams syndrome (WS). This article analyzes 178 published studies in the WS literature covering the following areas: 1) General intelligence, 2) Language skills, 3) Visuospatial and face processing skills, 4) Behavior patterns and hypersociability, 5) Musical abilities, and 6) Brain structure and function. We identify methodological issues relating to small sample size, use and type of control groups, and multiple measures of task performance. Previously described 'peaks' within the cognitive profile are closely examined to assess their veracity. This review highlights the need for methodologically sound studies that utilize multiple comparison groups, developmental trajectories, and longitudinal analyses to examine the WS phenotype, as well as those that link brain structure and function to the cognitive and behavioral phenotype of WS individuals.

Intonation abilities of children with Williams syndrome: a preliminary investigation

PURPOSE

The authors investigated expressive and receptive intonation abilities in children with Williams syndrome (WS) and the relation of these abilities to other linguistic abilities.

METHOD

Fourteen children with WS, 14 typically developing children matched to the WS group for receptive language (LA), and 15 typically developing children matched to the WS group for chronological age (CA) were compared on a range of receptive and expressive intonation tasks from the Profiling Elements of Prosodic Systems-Child version (PEPS-C) battery.

RESULTS

The WS group performed similarly to the LA group on all intonation tasks apart from the long-item imitation task, on which the WS group scored significantly lower than the LA group. When compared with the CA group, the WS group was significantly poorer on all aspects of intonation. Whereas there were a number of significant correlations between the intonation and language measures in the control groups, in the WS group, there was only 1 significant correlation between a PEPS-C task and one of the language measures.

CONCLUSION

As a result of this study, the authors concluded that children with WS have expressive and receptive intonation abilities as expected for their level of language comprehension and that intonation and other linguistic abilities in WS are not strongly related.

Comprehension of spatial language in Williams syndrome: evidence for impaired spatial representation of verbal descriptions

Individuals with the rare genetic disorder, Williams syndrome, have an unusual cognitive profile with relatively good language abilities but poor non-verbal and spatial skills. This study explored the interaction between linguistic and spatial functioning in Williams syndrome by investigating individuals' comprehension of spatial language. A group of 17 individuals with Williams syndrome and a control group of typically developing children were given two types of picture-matching task in which they were asked to select a picture to match a spoken sentence describing the spatial relation between two items. In the first task this matching could be done on the basis of existing semantic knowledge. In the second, we argue that a mental representation of the spatial relations was required. Results demonstrated that individuals with Williams syndrome were selectively impaired on the second task relative to controls. The study therefore provides support for previous work demonstrating impaired comprehension of spatial language in this population. Furthermore, the results suggest that such impairments reflect a fundamental problem with processing spatial descriptions rather than merely a poor understanding of the semantics of spatial terms, which in turn has implications for the interaction between spatial abilities and language processing in general.

Do children with Williams syndrome really have good vocabulary knowledge? Methods for comparing cognitive and linguistic abilities in developmental disorders

The comparison of cognitive and linguistic skills in individuals with developmental disorders is fraught with methodological and psychometric difficulties. In this paper, we illustrate some of these issues by comparing the receptive vocabulary knowledge and non-verbal reasoning abilities of 41 children with Williams syndrome, a genetic disorder in which language abilities are often claimed to be relatively strong. Data from this group were compared with data from typically developing children, children with Down syndrome, and children with non-specific learning difficulties using a number of approaches including comparison of age-equivalent scores, matching, analysis of covariance, and regression-based standardization. Across these analyses children with Williams syndrome consistently demonstrated relatively good receptive vocabulary knowledge, although this effect appeared strongest in the oldest children.

Complex grammar in Williams syndrome

This study investigated knowledge of binding and raising in two groups of children with Williams syndrome (WS), 6-12 and 12-16-years-old, compared to typically developing (TD) controls matched on non-verbal MA, verbal MA, and grammar. In typical development, difficulties interpreting pronouns, but not reflexives, persist until the age of around 6, while raising is not mastered until about the age of 8 or 9. If grammar in WS is delayed, but develops in a fashion parallel to TD population, similar patterns of difficulties may be expected, although it has not been established whether the grammatical development is ever complete in the individuals with this disorder. Knowledge of the principle of binding which states that a reflexive must have a c-commanding antecedent, was found to be intact in all the participants, in line with previous reports in the literature. In contrast, children with WS younger than 12 showed a poorer performance on personal pronouns, like two groups of younger matched TD controls, suggesting a previously unreported delay in the acquisition of constraints regulating coreferential interpretation of pronouns. Both groups of children with WS showed an extremely limited comprehension of raised, as opposed to unraised structures. The revealed patterns indicate that, like in unimpaired populations, different aspects of grammar mature at distinct stages of language development in WS: reflexive binding is acquired earlier than constraints governing coreference. However, development of raising seems exceptionally delayed, and perhaps even unattainable, as data from several adults with WS studied in Perovic and Wexler (2006) show. If, as hypothesized by Hirsch and Wexler, the late development of raising is related in TD children to lack of maturation of the knowledge of A-chains or defective phases, it seems reasonable to hypothesize that the even later development of these structures in WS is related to an even later (if ever) maturation of the knowledge of these grammatical forms.

Are regular and irregular verbs dissociated in non-fluent aphasia?

The cognitive mechanisms and neuroanatomical substrates used by the brain to effortlessly generate morphologically complex words (write + ing --> writing) are little understood. The left inferior frontal gyrus (LIFG, including Broca's area) is often implicated as being involved, although its specific role is unclear. Data from brain damaged individuals, particularly those with Broca's aphasia, are often used as evidence to support or refute various theoretical perspectives. Typically, performance on two types of morphologically complex verbs, regulars (walk-walked, slip-slipped) and irregulars (sing-sang, sleep-slept) is contrasted for evidence of single or double dissociations. The question of how Broca's aphasic individuals dissociate in their production of inflectional morphology is important to our understanding of how the brain is organized to compute morphologically complex words. This article is a synthesis of research studies investigating the production of morphologically complex regular and irregular verbs in individuals with Broca's aphasia. The question being asked is if there is a robust and consistent dissociation, and if this dissociation can be tied to lesions of the left frontal lobe. This meta-analysis of 75 patients failed to show a single consistent dissociation pattern and over half the datasets had no significant difference between regulars and irregulars. There was also no relationship of any performance pattern to frontal lobe lesions, highlighting the difficulty of identifying any single neuroanatomical lesion for regular-irregular verb production deficits. The implications for various theoretical and neuroanatomical hypotheses are discussed. The role of neuropsychological dissociations in constraining hypothesis of normal neuroanatomical organization is evaluated.

Patterns of syntactic development in children with Williams syndrome and Down's syndrome: evidence from passives and wh-questions

This study investigates the syntactic abilities of ten individuals with Williams syndrome (WS) (mean chronological age: 8;9 years; mean mental age: 4;8 years) and Down's syndrome (DS) (mean chronological age: 8;7 years; mean mental age: 4;6 years), matched individually on chronological age, mental age and performance IQ. The syntactic components investigated include the comprehension of passives and the production, comprehension and repetition of wh-questions. Performance is compared to ten younger typically developing (TD) controls matched individually to both experimental groups on mental age (mean chronological age: 4;4 years; mean mental age: 5;0 years). Participants were given a standardized measure of grammatical ability and non-standardized tasks exploring the comprehension of active and passive sentences, and the production, comprehension and repetition of a range of wh-question types: wh-subject, wh-object, which NP-subject and which NP-object. Participants with WS and DS performed similarly on the standardized measure of grammatical ability, as well as on the experimental tasks that tapped comprehension of passives, and production and comprehension of wh-questions. Participants with DS performed significantly more poorly than both the WS cohort and TD controls on the repetition of wh-questions. Both the WS and DS cohorts performed significantly more poorly on most of the syntactic tasks compared to the younger TD controls. Individuals with WS and DS experienced significant difficulties in tasks measuring aspects of syntactic ability and performed more poorly than mental age-matched TD controls. Implications of these findings, with regards to the debates around language "intactness" in WS, as well as the similarities and differences in language abilities in WS and DS, dependent on age and developmental stages studied, are explored.

Affective prosody in children with Williams syndrome

The aim of the current study was to investigate expressive affect in children with Williams syndrome (WS) in comparison to typically developing children in an experimental task and in spontaneous speech. Fourteen children with WS, 14 typically developing children matched to the WS group for receptive language (LA) and 15 typically developing children matched to the WS groups for chronological age (CA) were recruited. Affect was investigated using an experimental Output Affect task from the Profiling Elements of Prosodic Systems-Child version (PEPS-C) battery, and by measuring pitch range and vowel durations from a spontaneous speech task. The children were also rated for level of emotional involvement by phonetically naïve listeners. The WS group performed similarly to the LA and CA groups on the Output Affect task. With regard to vowel durations, the WS group was no different from the LA group; however both the WS and the LA groups were found to use significantly longer vowels than the CA group. The WS group differed significantly from both control groups on their range of pitch range and was perceived as being significantly more emotionally involved than the two control groups.

Mathematical skill in individuals with Williams syndrome: evidence from a standardized mathematics battery

Williams syndrome (WS) is a developmental disorder associated with relatively spared verbal skills and severe visuospatial deficits. It has also been reported that individuals with WS are impaired at mathematics. We examined mathematical skills in persons with WS using the second edition of the Test of Early Mathematical Ability (TEMA-2), which measures a wide range of skills. We administered the TEMA-2 to 14 individuals with WS and 14 children matched individually for mental-age on the matrices subtest of the Kaufman Brief Intelligence Test. There were no differences between groups on the overall scores on the TEMA-2. However, an item-by-item analysis revealed group differences. Participants with WS performed more poorly than controls when reporting which of two numbers was closest to a target number, a task thought to utilize a mental number line subserved by the parietal lobe, consistent with previous evidence showing parietal abnormalities in people with WS. In contrast, people with WS performed better than the control group at reading numbers, suggesting that verbal math skills may be comparatively strong in WS. These findings add to evidence that components of mathematical knowledge may be differentially damaged in developmental disorders.

The relation between language and cognition in 3- to 9-year-olds: the acquisition of grammatical gender in French

The French language has a grammatical gender system in which all nouns are assigned either a masculine or a feminine gender. Nouns provide two types of gender cues that can potentially guide gender attribution: morphophonological cues carried by endings and semantic cues (natural gender). The first goal of this study was to describe the acquisition of the probabilistic system based on phonological oppositions on word endings by French-speaking children. The second goal was to explore the extent to which this system affects categorization. In the study, 3- to 9-year-olds assigned gender categorization to invented nouns whose endings were typically masculine, typically feminine, or neutral. Two response conditions were used. In the determiner condition, children indicated the gender class by orally providing the determiner un or une marked for gender. In the picture condition, responses were given by pointing to the picture of a Martian-like female or male person that would be best called by each spoken pseudoword. Results indicated that as young as 3 years, children associated the determiner corresponding to the ending bias at greater than chance levels. Ending-consistent performance increased from 3 to 9 years of age. Moreover, from 4 years of age onward, sensitivity to endings affected categorization. Starting at that age, pictures were selected according to endings at greater than chance levels. This effect also increased with age. The discussion deals with the mechanisms of language acquisition and the relation between language and cognition.

Rearrangements of the Williams-Beuren syndrome locus: molecular basis and implications for speech and language development

The Williams-Beuren syndrome (WBS) locus on human chromosome 7q11.23 is flanked by complex chromosome-specific low-copy repeats that mediate recurrent genomic rearrangements of the region. Common genomic rearrangements arise through unequal meiotic recombination and result in complex but distinct behavioural and cognitive phenotypes. Deletion of 7q11.23 results in WBS, which is characterised by mild to moderate intellectual disability or learning difficulties, with relative cognitive strengths in verbal short-term memory and in language and extreme weakness in visuospatial construction, as well as anxiety, attention-deficit hyperactivity disorder and overfriendliness. By contrast, duplication results in severely delayed speech and expressive language, with relative strength in visuospatial construction. Although deletion and duplication of the WBS region have very different effects, both cause forms of language impairment and suggest that dosage-sensitive genes within the region are important for the proper development of human speech and language. The spectrum and frequency of genomic rearrangements at 7q11.23 presents an exceptional opportunity to identify gene(s) directly involved in human speech and language development.

Language abilities in Williams syndrome: a critical review

Williams syndrome is a rare genetic disorder in which, it is claimed, language abilities are relatively strong despite mild to moderate mental retardation. Such claims have, in turn, been interpreted as evidence either for modular preservation of language or for atypical constraints on cognitive development. However, this review demonstrates that there is, in fact, little evidence that syntax, morphology, phonology, or pragmatics are any better than predicted by nonverbal ability, although performance on receptive vocabulary tests is relatively good. Similarly, claims of an imbalance between good phonology and impaired or atypical lexical semantics are without strong support. There is, nevertheless, consistent evidence for specific deficits in spatial language that mirror difficulties in nonverbal spatial cognition, as well as some tentative evidence that early language acquisition proceeds atypically. Implications for modular and neuroconstructivist accounts of language development are discussed.

Language and communicative development in Williams syndrome

Williams syndrome, a genetic disorder caused by a microdeletion of approximately 25 genes on chromosome 7q11.23, is associated with mild to moderate intellectual disability or learning difficulties. Most individuals with Williams syndrome evidence a cognitive profile including relative strengths in verbal short-term memory and language, and considerable weakness in visuospatial construction. The syndrome has often been argued to provide strong evidence for the independence of language from other aspects of cognition. We provide a brief history of early research on the language abilities of individuals with Williams syndrome and then review contemporary studies of language and cognition in Williams syndrome, beginning with a consideration of performance on standardized assessments. In the remainder of the article, we first consider early language acquisition, with a focus on speech production and perception, vocabulary acquisition, and communicative/pragmatic development and then consider the language abilities of school-age children and adolescents, focusing on semantics, grammar, and pragmatics. We argue that rather than being the paradigm case for the independence of language from cognition, Williams syndrome provides strong evidence of the interdependence of many aspects of language and cognition.

The tortuous route from genes to behavior: A neuroconstructivist approach

In their excitement at using the human genome project to uncover the functions of specific genes, researchers have often ignored one fundamental factor: the gradual process of ontogenetic development. The view that there might be a gene for spatial cognition or language has emanated from a focus on the structure of the adult brain in neuropsychological patients whose brains were fully and normally developed until their brain insult. The developing brain is very different. It starts out highly interconnected across regions and is neither localized nor specialized at birth, allowing interaction with the environment to play an important role in gene expression and the ultimate cognitive phenotype. This article takes a neuroconstructivist perspective, arguing that domain-specific end states can stem from more domain-general start states, that associations may turn out to be as informative as dissociations, and that genetic mutations that alter the trajectory of ontogenetic development can inform nature/nurture debates.

Development of the Grammar and Phonology Screening (GAPS) test to assess key markers of specific language and literacy difficulties in young children

BACKGROUND

Despite a large body of evidence regarding reliable indicators of language deficits in young children, there has not been a standardized, quick screen for language impairment. The Grammar and Phonology Screening (GAPS) test was therefore designed as a short, reliable assessment of young children's language abilities.

AIMS

GAPS was designed to provide a quick screening test to assess whether pre- and early school entry children have the necessary grammar and pre-reading phonological skills needed for education and social development. This paper reports the theoretical background to the test, the pilot study and reliability, and the standardization.

METHODS

This 10-min test comprises 11 test sentences and eight test nonsense words for direct imitation and is designed to highlight significant markers of language impairment and reading difficulties. To standardize the GAPS, 668 children aged 3.4-6.6 were tested across the UK, taking into account population distribution and socio-economic status. The test was carried out by a range of health and education professionals as well as by students and carers using only simple, written instructions.

RESULTS

GAPS is effective in detecting a range of children in need of further in-depth assessment or monitoring for language difficulties. The results concur with those from much larger epidemiological studies using lengthy testing procedures.

CONCLUSIONS

The GAPS test (1) provides a successful screening tool; (2) is designed to be administered by professionals and non-professionals alike; and (3) facilitates identification of language impairment or at-risk factors of reading impairment in the early educational years. Thus, the test affords a first step in a process of assessment and targeted intervention to enable children to reach their potential.

Investigating prosodic ability in Williams syndrome

This paper investigates whether people with Williams syndrome (WS) have prosodic impairments affecting their expression and comprehension of four main uses of intonation. Two adolescent males with WS were assessed using the PEPS-C battery, which considers prosodic abilities within a psycholinguistic framework, assessing prosodic form and function in both the input and output domains. The performances of the subjects with WS were compared with control data for age and language-comprehension matched children. The results revealed significant prosodic impairment affecting all areas of the profile. Crucially, however, different profiles of strengths and weaknesses were revealed for the two subjects. The results support the growing view that WS is a heterogeneous population in terms of linguistic abilities.

Linguistic heterogeneity in Williams syndrome

Williams syndrome (WS) is a rare genetic disorder resulting from a deletion on chromosome 7. A number of studies have shown that individuals with WS have a superior linguistic profile compared to their non-verbal abilities, however the evidence has been inconclusive, as many studies have disputed such a profile. The vast majority of studies on WS have assumed a single, homogeneous WS linguistic profile in order to support various theoretical viewpoints. The present study investigated the linguistic profiles of 5 individuals with WS on a number of standardized verbal measures and in conversational settings. The results indicated substantially variable performance in all aspects of the verbal domain, which supports the view that WS, linguistically, is a rather heterogeneous condition and this should be taken into consideration when referring to it in theoretical accounts of language acquisition and debates on modularity.

Translational research on early language development: Current challenges and future directions

There is a pressing need for the early and accurate identification of young children at risk for language and other developmental disabilities and the provision of timely, age-appropriate intervention, as mandated by Part C of the Individuals with Disabilities Education Act. Research has shown that early intervention is effective for many language impaired children in different etiological groups, and can reduce the functional impact of persistent disorders on children and their families. Yet, the accurate identification of infants and toddlers at risk for language impairment remains elusive, especially for late-talking children without obvious genetic or neurological conditions. In this paper, the need for translational research on basic processes in early language development in typical and atypical populations and the contextual factors that affect them are discussed, along with current challenges and future directions for its successful implementation. Implications of this research for clinical evidence-based practice are also considered.

Stochastic approaches to understanding dissociations in inflectional morphology

Computer modelling research has undermined the view that double dissociations in behaviour are sufficient to infer separability in the cognitive mechanisms underlying those behaviours. However, all these models employ multi-modal representational schemes, where functional specialisation of processing emerges from the training process. Targeted lesioning of different regions of functional specialisation leads to varied but predictable deficits in model performance. We argue that multi-modal representational schemes are not a necessary condition for the observation of double dissociations in an information processing system that shares resources across multiple tasks. Using a uni-modal representational system, we demonstrate that double dissociations may also result from stochastic processes. Lesioning experiments on a single-route, uni-modal connectionist model of regular and irregular noun and verb morphology confirm and extend earlier work demonstrating that selective impairment across tasks can result from damage to a distributed information processing system. A systematic investigation of the degree to which performance deteriorates across different inflectional classes reveals that simple and double dissociations can occur in this single-route, uni-modal model. An important prediction of the model is that double dissociations between regular and irregular inflection, resulting from stochastic processes should be extremely rare. However, they are particularly likely to occur when the researcher uses test batteries consisting of a small number of items. Given that cognitive neuropsychologists rarely provide details about the distribution of performance in a disordered population, it is concluded that a stochastic interpretation of double dissociations may have wider applicability than is normally supposed.

The role of meaning in past-tense inflection: evidence from polysemy and denominal derivation

Although English verbs can be either regular (walk-walked) or irregular (sing-sang), "denominal verbs" that are derived from nouns, such as the use of the verb ring derived from the noun a ring, take the regular form even if they are homophonous with an existing irregular verb: The soldiers ringed the city rather than *The soldiers rang the city. Is this regularization due to a semantic difference from the usual verb, or is it due to the application of the default rule, namely VERB+ -ed suffix? In Experiment 1, participants rated the semantic similarity of the extended senses of polysemous verbs and denominal verbs to their central senses. Experiment 2 examined the acceptability of the regular and irregular past tenses of the different verbs. The results showed that all the denominal verbs were rated as more acceptable for the regular inflection than the same verbs used polysemously, even though the two were semantically equally similar to the central meaning. Thus, the derivation of the verb (nominal or verbal) determined the past-tense preference more than semantic variables, consistent with dual-route models of verb inflection.

Object recognition with severe spatial deficits in Williams syndrome: sparing and breakdown

Williams syndrome (WS) is a rare genetic disorder that results in severe visual-spatial cognitive deficits coupled with relative sparing in language, face recognition, and certain aspects of motion processing. Here, we look for evidence for sparing or impairment in another cognitive system-object recognition. Children with WS, normal mental-age (MA) and chronological age-matched (CA) children, and normal adults viewed pictures of a large range of objects briefly presented under various conditions of degradation, including canonical and unusual orientations, and clear or blurred contours. Objects were shown as either full-color views (Experiment 1) or line drawings (Experiment 2). Across both experiments, WS and MA children performed similarly in all conditions while CA children performed better than both WS group and MA groups with unusual views. This advantage, however, was eliminated when images were also blurred. The error types and relative difficulty of different objects were similar across all participant groups. The results indicate selective sparing of basic mechanisms of object recognition in WS, together with developmental delay or arrest in recognition of objects from unusual viewpoints. These findings are consistent with the growing literature on brain abnormalities in WS which points to selective impairment in the parietal areas of the brain. As a whole, the results lend further support to the growing literature on the functional separability of object recognition mechanisms from other spatial functions, and raise intriguing questions about the link between genetic deficits and cognition.

A challenge to current models of past tense inflection: The impact of phonotactics

Is past tense production better modelled by a Single Mechanism or a Words and Rules model? We present data concerning a phenomenon that has not been considered by either model-regular past tense verbs with contrasting phonotactics. One set of verbs contains clusters at the inflected verb end that also occur in monomorphemic words ('monomorphemically legal clusters', MLC) whereas the other has clusters that can only occur in inflected forms ('monomorphemically illegal clusters', MIC). We argue that if children apply a morphological rule, phonotactics will not affect performance. Conversely, if children store past tense forms, they will perform better on verbs with MLCs because these clusters are more frequent. We investigated three populations--typically developing children, Grammatical-SLI (G-SLI) and Williams Syndrome (WS)--using past tense elicitation tasks. In Experiment 1 we reanalyse data from van der Lely and Ullman [van der Lely, H. K. J. & Ullman, M. (2001). Past tense morphology in specifically language impaired and normally developing children. Language and Cognitive Processes, 16: 177-217] and show that G-SLI children perform better on MLC verbs, whereas for typically developing children phonotactics do not affect performance. In Experiment 2 we replicate these findings in new groups of G-SLI and typically developing children. In Experiment 3 we reanalyse data from Thomas et al. [Thomas, M. S. C., Grant, J., Barham, Z., Gsodl, M., Laing, E., Lakusta, L., Tyler, L.K., Grice, S., Paterson, S. & Karmiloff-Smith, A. (2001) Past tense formation in Williams Syndrome. Language and Cognitive Processes, 16: 143-176] and show that phonotactics do not affect performance in individuals with WS. We argue that the results elucidate the underlying nature of morphology in these populations, and are better accommodated within a Words and Rules model of past tense acquisition.

Short-term longitudinal study of a child with Williams syndrome

BACKGROUND

The superiority of language and communication skills in children and adults with Williams syndrome (WS) is currently being debated. Whilst there have been a number of reports of precursors of language in WS in children who have already developed language, there have not been many studies that have prospectively investigated precursors of language in pre-verbal children with WS.

AIMS

To investigate the development of early social communication skills before the onset of language in WS.

METHODS & PROCEDURES

A short-term longitudinal single case study was carried out spanning 10 months. The child was assessed five times using parent report, observation of mother-child interactions and by administering the Pre-verbal Communication Schedule, the Pragmatics Profile of Early Communication Skills and the Pre-School Language Scale - 3.

OUTCOMES & RESULTS

Longitudinal comparisons showed that the level of verbal communication in the child with WS always lagged behind the level of motor and cognitive development.

CONCLUSIONS

The results indicate that rather than being a strength, social communication was an area of weakness relative to other aspects of development in this case. This case raises the potential desirability for early speech and language assessment and intervention in infants with WS.