Williams Syndrome Individuals Research Articles

Amygdala Volume and Sociability in Williams Syndrome and Normal Controls

Event Abstract Back to Event Amygdala Volume and Sociability in Williams Syndrome and Normal Controls M. A. Martens1, 2, 3*, S. J. Wilson3 and D. C. Reutens4 1 The Ohio State University, Department of Psychology, United States 2 The Ohio State University, Nisonger Center, United States 3 The University of Melbourne, School of Behavioural Science, Australia 4 The University of Melbourne, Department of Medicine, Australia The amygdala has been implicated in recognition of emotions in facial expression. Individuals with Williams syndrome (WS) have been found to view unfamiliar faces as more approachable than normal controls. The current research investigated the relationship between amygdala volume and approachability in both normal controls and individuals with WS. Twenty-two individuals with WS (mean age 17.1, SD 7.3 years; range 8-41 years) and 22 healthy controls matched for age, sex, and handedness (mean age 17.1, SD 7.3 years; range 8-41 years) underwent T1-weighted high-resolution MRI brain scans and rated the approachability of unfamiliar faces (Adolphs, 1998). The results showed that individuals with WS rated the unfamiliar faces as significantly more friendly than controls [t(40)=2.29, p=.02], supporting the trait of hypersociability in WS. Despite an 18% reduction in overall brain volume for individuals with WS, the volumes of left and right amygdala were similar in individuals with WS and controls. The average approachability rating of all faces for each participant in both groups was regressed against right and left amygdalar volume. Both group and right amygdalar volume contributed significantly to the variance in the approachability ratings. Furthermore, in comparison to controls, individuals with WS made significantly fewer comments about features of the eyes and mouth than controls [t(39)=-3.30, p=.002] and significantly more comments about peripheral features [t(39)=3.47, p=.003], suggesting that WS individuals may use atypical facial processing when determining how friendly a person appears. Conference: 12th International Professional Conference on Williams Syndrome, Garden Grove,CA, United States, 13 Jul - 14 Jul, 2008. Presentation Type: Poster Presentation Topic: Multidisciplinary Poster Session Citation: Martens MA, Wilson SJ and Reutens DC (2009). Amygdala Volume and Sociability in Williams Syndrome and Normal Controls. Conference Abstract: 12th International Professional Conference on Williams Syndrome. doi: 10.3389/conf.neuro.09.2009.07.049 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 04 May 2009; Published Online: 04 May 2009. * Correspondence: M. A Martens, The Ohio State University, Department of Psychology, Newark, United States, martens.22@osu.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers M. A Martens S. J Wilson D. C Reutens Google M. A Martens S. J Wilson D. C Reutens Google Scholar M. A Martens S. J Wilson D. C Reutens PubMed M. A Martens S. J Wilson D. C Reutens Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Normal Susceptibility to Visual Illusions in Abnormal Development: Evidence from Williams Syndrome

The perception of visual illusions is a powerful diagnostic of implicit integration of global information. Many illusions occur when length, size, orientation, or luminance are misjudged because neighboring visuospatial information cannot be ignored. We asked if people with Williams syndrome (WS), a rare genetic disorder that results in severely impaired global visuospatial construction abilities, are also susceptible to the context of visual illusions. Remarkably, we found that illusions influenced WS individuals to the same degree as normal adults, although size discrimination was somewhat impaired in WS. Our results are evidence that illusions are a consequence of the brain's bias to implicitly integrate visual information, even in a population known to have difficulty in explicitly representing spatial relationships among objects. Moreover, these results suggest that implicit and non-implicit integration of spatial information have different vulnerabilities in abnormal development.

Visuospatial interpolation in typically developing children and in people with Williams Syndrome

Visuospatial interpolation is the estimation of object position or contour shape computed from known “anchor” positions. We characterized the developmental profile of interpolation by measuring positional thresholds as a function of inter-element separation without (Experiment 1) and with (Experiment 2) the context of illusory contours in typically developing children, typical adults and individuals with Williams Syndrome (WS), a genetic disorder that causes impaired global visuospatial abilities. We found that typically developing children and WS individuals had more difficulty integrating information across distant elements than typical adults. However, illusory contours improved thresholds in all participant groups in a similar way. Our results suggest that in WS individuals, and in typically developing children, the grouping mechanisms that enable long-range spatial integration are immature. We hypothesize that WS individuals and young children can use stimulus-driven grouping cues for bottom–up integration, but have immature mechanisms for top–down integration of spatial information.

Vision for perception and vision for action: normal and unusual development

Evidence suggests that visual processing is divided into the dorsal ('how') and ventral ('what') streams. We examined the normal development of these streams and their breakdown under neurological deficit by comparing performance of normally developing children and Williams syndrome individuals on two tasks: a visually guided action ('how') task, in which participants posted a card into an oriented slot, and a perception ('what') task, in which they matched a card to the slot's orientation. Results showed that all groups performed worse on the action task than the perception task, but the disparity was more pronounced in WS individuals and in normal 3-4-year-olds than in older children. These findings suggest that the 'how' system may be relatively slow to develop and more vulnerable to breakdown than the 'what' system.

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.

Implicit memory is independent from IQ and age but not from etiology: evidence from Down and Williams syndromes

In the last few years, experimental data have been reported on differences in implicit memory processes of genetically distinct groups of individuals with Intellectual Disability (ID). These evidences are relevant for the more general debate on supposed asynchrony of cognitive maturation in children with abnormal brain development. This study, comparing implicit memory processes in individuals with Williams syndrome (WS) and Down syndrome (DS), was planned to verify the 'etiological specificity' hypotheses pertaining to the skill learning abilities of individuals with ID. A modified version of Nissen and Bullemer's (1987) Serial Reaction Time (SRT) task was used. The performances of three group were evaluated. The first group consisted of thirty-two people with WS (18 males and 14 females). The second group was comprised of twenty-six individuals with DS (14 males and 12 females). The two groups of individuals with ID were selected so that the groups were comparable as for mental age and chronological age. The third group consisted of forty-nine typically developed children with a mental age similar to that of the groups with WS and DS. The two groups of individuals with ID demonstrated different patterns of procedural learning. WS individuals revealed poor implicit learning of the temporal sequence of events characterizing the ordered blocks in the SRT task. Indeed, differently from normal controls, WS participants showed no reaction time (RT) speeding through ordered blocks. Most importantly, the rebound effect, which so dramatically affected normal children's RTs passing from the last ordered to the last block, had only a marginal influence on WS children's RTs. Differently from the WS group, the rate of procedural learning of the participants with DS was comparable to that of their controls. Indeed, DS and typically developed individuals showed parallel RT variations in the series of ordered blocks and, more importantly, passing from the last ordered to the last block. Therefore, a substantial preservation of skill learning abilities in this genetic syndrome is confirmed. The results of the present study document that procedural learning in individuals with ID depends on the aetiology of the syndrome, thus supporting the etiological specificity account of their cognitive development. These results are relevant for our knowledge about the qualitative aspects and the underlying neurobiological substrate of the anomalous cognitive development in mentally retarded people.

More Is Not Always Better: Increased Fractional Anisotropy of Superior Longitudinal Fasciculus Associated with Poor Visuospatial Abilities in Williams Syndrome

We used diffusion tensor imaging to examine white matter integrity in the dorsal and ventral streams among individuals with Williams syndrome (WS) compared with two control groups (typically developing and developmentally delayed) and using three separate analysis methods (whole brain, region of interest, and fiber tractography). All analysis methods consistently showed that fractional anisotropy (FA; a measure of microstructural integrity) was higher in the right superior longitudinal fasciculus (SLF) in WS compared with both control groups. There was a significant association with deficits in visuospatial construction and higher FA in WS individuals. Comparable increases in FA across analytic methods were not observed in the left SLF or the bilateral inferior longitudinal fasciculus in WS subjects. Together, these findings suggest a specific role of right SLF abnormality in visuospatial construction deficits in WS.

Theory of Mind in Williams Syndrome Assessed Using a Nonverbal Task

This study examined Theory of Mind in Williams syndrome (WS) and in normal chronological age-matched and mental age-matched control groups, using a picture sequencing task. This task assesses understanding of pretence, intention and false belief, while controlling for social-script knowledge and physical cause-and-effect reasoning. The task was selected because it is entirely non-verbal, so that the WS individuals could not rely on their good verbal skills when performing the task. Results indicated a specific deficit in understanding of false belief within the WS group. There was also evidence of heterogeneity in the WS group, with the false belief impairment restricted to only a particular subgroup of WS individuals identified originally by Porter, M., & Coltheart, M. (2005). Cognitive heterogeneity in Williams syndrome. Developmental Neuropsychology, 27(2), 275-306.

Callosal morphology in Williams syndrome: a new evaluation of shape and thickness

We applied novel mesh-based geometrical modeling methods to calculate and compare the thickness of the corpus callosum at high spatial resolution and to create profiles of average callosal shape in a well-matched sample (n=24) of individuals with Williams syndrome and controls. In close agreement with previous observations, superimposed surface maps indicate that the corpus callosum in Williams syndrome individuals is shorter and less curved. Moreover, we observed significantly thinner callosal regions in Williams syndrome individuals across the posterior surface, where group effects were less pronounced and spatially restricted in brain-size-adjusted data compared with native data. Circumscribed structural alterations in callosal morphology might be candidate anatomic substrates for the unique cognitive and behavioral profile associated with Williams syndrome.

Global and Local Processing in Williams Syndrome, Autism, and Down Syndrome: Perception, Attention, and Construction

Global and local processing was studied in Williams Syndrome (WS), autism (AS), and Down Syndrome (DS) using perception, attention, and construction tasks. Past research has suggested an abnormal bias toward global processing in DS and, in contrast, an abnormal local bias in both WS and AS. Until now, no study has investigated whether the local processing bias in WS and AS has a different or similar underlying cause. Findings here suggest a common underlying mechanism, namely a bias in attention toward local processing. Results also indicate a global bias in attention in DS. This study finds no evidence to support predictions of the hierarchical deficit theory (Mottron & Belleville, 1993) as an explanation of hierarchical processing deficits in AS or DS, but does find support for hierarchical deficit theory in a subset of WS individuals. This study finds evidence of cognitive heterogeneity in WS, consistent with Porter and Coltheart (2005).

Reconnaissance des visages chez les enfants porteurs du syndrome de Williams

Williams Syndrome (WS) is a developmental disorder with a unique cognitive profile. Previous studies underlined the existence of a strong dissociation between language and other cognitive functions; this non uniform pattern has also been observed in the domain of spatial cognition with difficulties in configural processing and part integration tasks. Paradoxically, some authors have described a selective preservation of face recognition in WS subjects while these abilities typically rely on configural analysis. Our main objective was then to further explore configural face processing in children and adolescents with WS. Face processing competences were evaluated in a group of WS children through a series of experiments which tapped different aspects of configural processing. Performance of WS individuals was compared to that of a group of children individually matched for chronological age (CA-matches) and to that of another group matched for mental age (MA-matches). Taken together, the results obtained in the current study revealed that some but not all aspects of configural processing undergo an abnormal developmental course in the WS pathology.

Dorsal-stream motion processing deficits persist into adulthood in Williams syndrome

Previous studies of children with Williams syndrome (WS) have found a specific deficit in dorsal cortical stream function, indicated by poor performance in coherence thresholds for motion compared to form. Here we investigated whether this is a transient developmental feature or a persisting aspect of cerebral organization in WS. Motion and form coherence thresholds were tested in a group of 45 WS individuals aged 16–42 years, and 19 normal adult controls. Although there was considerable variation in the coherence thresholds across individuals with WS, the WS group showed overall worse performance than controls. A significant group × threshold condition interaction showed a substantially greater performance deficit for motion than for form coherence in the WS group relative to controls. This result suggests that the motion deficit is an enduring feature in WS and is a marker for one aspect of dorsal-stream vulnerability.

Motion processing specialization in Williams syndrome

Williams syndrome (WS) is a rare genetic disorder characterized by severe spatial deficits and relatively spared language. Although initial research suggested that WS entails a generalized motion processing deficit, later work demonstrated intact biological motion perception in people with WS, reflecting a sparing of a specific motion perception system. The present study examined whether this sparing is unique to biological motion, or extends to other motion tasks as well. WS children and adults and normal controls were tested to examine developmental changes across a variety of motion tasks. Results indicated that WS individuals performed at normal levels for motion coherence and biological motion tasks but had elevated thresholds for the 2-D form-from-motion task, a profile that extended into adulthood. These findings provide evidence that a genetic impairment can lead to a selective motion processing deficit and argue against characterizing WS as including a general motion processing impairment. The nature of the motion deficit is considered, including the implications for WS dorsal/ventral processing.

Neuropsychological, neurological, and neuroanatomical profile of Williams syndrome

The general aim of our research is to understand the brain mechanisms that underlie language and cognition. In this paper, we present a new line of investigation which attempts to forge links between a specific neurodevelopmental disorder, a specific neuropsychological profile, and abnormal brain organization. We report on a dissociation between language and cognitive functions in Williams syndrome adolescents, in contrast to age- and IQ-matched Down syndrome adolescents. The Williams syndrome individuals exhibit an unusual fractionation of higher cortical functioning, with marked cognitive deficits, but selective sparing of syntax. Differences in spatial cognitive abilities in the 2 groups are investigated, showing peaks and valleys of abilities specific to Williams syndrome individuals. These neurobehavioral profiles are explored in light of new evidence regarding neurologic and neuroanatomical differences between the 2 matched groups of adolescents. Results from these combined studies should help clarify the neural systems that mediate language and cognitive functions.

Williams syndrome: An historical perspective of its evolution, natural history, and etiology

This review examines the Williams syndrome (WS) from an historical perspective, beginning with the early descriptions of idiopathic infantile hypercalcemia (IIH) and ending with some speculative ideas about a possible causative function of a recently discovered neuropeptide. The earliest reports of WS individuals are probably those which describe a "severe" subgroup of IIH and separate it from the epidemic of milder IIH reported in Post-WWII Great Britain and Europe. Most of these latter cases apparently resulted from hypervitaminosis D produced by excessive supplementation of government-supplied infant foods. With more extensive recognition and reporting of this "severe" subgroup, the diagnostic constellation of IIH, mental deficiency, elfin face, and supravalvular aortic stenosis (SVAS) evolved as WS. More of these reports emphasized the physical and behavioral manifestations as the key diagnostic features, and the frequency of occurrence and relative importance of SVAS and IIH in WS decreased. Despite the diminished consequence of hypercalcemia, calcium and vitamin D have continued to dominate the investigation of the cause of infantile hypercalcemia and led to the proposal and confirmation of deficient calcitonin secretion in individuals with WS. Though calcitonin is probably pertinent only to infantile hypercalcemia, its alternative gene product, calcitonin-gene-related product, is an important neuropeptide with physiological effects in the central nervous system and cardiovascular systems which raise the possibility that it may be responsible for some of the manifestations of WS.

Cognitive Heterogeneity in Williams Syndrome

This study used the Woodcock-Johnson Tests of Cognitive Ability-Revised to investigate a wide range of cognitive abilities in people with Williams syndrome (WS). It involved a comparatively large sample of 31 people with WS, but took a case-series approach. The study addressed the widespread claims of a characteristic "WS cognitive profile" by looking for heterogeneity rather than homogeneity. People with WS showed a variety of preserved (significantly above mental age [MA]), expected (at MA), and significantly impaired (significantly below MA) levels of functioning. Such results provide clear evidence for heterogeneity in cognitive functions within WS. We found the most homogeneity on a test of phonological processing and a test of phonological short-term memory, with half of the WS sample performing at MA levels on these tests. Interestingly, no WS individual showed a weakness on a test of nonverbal reasoning, and only one WS individual showed a weakness on a test of verbal comprehension. In addition, we found that strengths on analysis-synthesis and verbal analogies occurred only for WS individuals with an MA less than 5.5 years (our sample median MA); people with an MA greater than 5.5 years performed at MA level on these 2 tests. Results also provided preliminary evidence for distinct subgroups of WS people based on their cognitive strengths and weaknesses on a broad range of cognitive functions. On the basis of the findings, caution should be made in declaring a single cognitive profile that is characteristic of all individuals with WS. Just as there is heterogeneity in genetic and physical anomalies within WS, not all WS individuals share the same cognitive strengths and weaknesses. Also, not all WS individuals show the profile of a strength in verbal abilities and a weakness in spatial functions.

Global and local music perception in children with Williams syndrome

Musical processing can be decomposed into the appreciation of global and local elements. This global/local dissociation was investigated with the processing of contour-violated and interval-violated melodies. Performance of a group of 16 children with Williams syndrome and a group of 16 control children were compared in a same-different task. Control participants were more accurate in detecting differences in the contour-violated than in the interval-violated condition while Williams syndrome individuals performed equally well in both conditions. This finding suggests that global precedence may occur at an early perceptual stage in normally developing children. In contrast, no such global precedence is observed in the Williams syndrome population. These data are discussed in the context of atypical cognitive profiles of individuals with Williams syndrome.

Characterizing the Musical Phenotype in Individuals With Williams Syndrome

Williams Syndrome (WS), a neurodevelopmental genetic disorder, is characterized by peaks and valleys in mental function: substantial impairments in cognitive domains such as reasoning, arithmetic ability, and spatial cognition, alongside relatively preserved skills in social domains, face processing, language, and music. We report the results of a comprehensive survey on musical behaviors and background administered to the largest sample of individuals with WS to date (n = 118, mean age = 20.4), and compare the results to those obtained from a control group of typically developing normal individuals (n = 118, mean age = 20.9) and two groups of individuals with other neurodevelopmental genetic disorders, Autism (n = 30, mean age = 18.2) and Down Syndrome (n = 40, mean age = 17.2). Individuals with WS were found to be rated higher in musical accomplishment, engagement, and interest than either of the comparison groups, and equivalent on most measures to the control group. Compared to all other groups including the controls, the WS individuals displayed greater emotional responses to music, manifested interest in music at an earlier age, and spent more hours per week listening to music. In addition, the effects of music listening (whether positive or negative) tended to last longer in the WS group. A factor analysis extracted seven principal components that characterize the musical phenotype in our sample, and discriminant function analysis of those factors was able to successfully predict group membership for the majority of cases. We discuss the neurobiological implications of these findings.

Les troubles visuo-constructifs dans le syndrome de Williams

Résumé Le syndrome de Williams est un trouble d'origine génétique qui se manifeste par un profil neuropsychologique hétérogène dans lequel les capacités langagières sont relativement préservées alors que d'importants déficits sont présents dans la sphère visuo-constructive. Après un bref survol des capacités langagières, nous nous centrons sur les troubles visuo-constructifs pour lesquels nous décrivons les résultats obtenus avec les principaux paradigmes. Ensuite, nous discutons les différentes interprétations proposées, génétiques, neurologiques et psychologiques. Dans ces dernières, nous présentons l'hypothèse d'un déficit du traitement global habituellement invoquée pour décrire les dysfonctionnements visuo-constructifs que nous confrontons avec des données récentes portant sur le rôle éventuel de la perception, de la mémoire à court terme visuelle, de l'imagerie mentale et des fonctions executives. Nous présentons une nouvelle hypothèse : les personnes SW ont des difficultés à se désengager du traitement local lorsqu'elles doivent reconstruire des stimuli visuels. Mots-clés : syndrome de Williams, reconstruction visuo-spatiale, variables psychologiques, traitement local-global.

Residual Normality and the issue of language profiles in Williams syndrome

One of the debated issues regarding Residual Normality (RN) is frequency sensitivity in Williams syndrome (WS). We present some data on frequency sensitivity in Hungarian WS subjects. Based on vocabulary measures, we suggest that instead of the across-the-board frequency insensitivity proposed by some, a higher frequency threshold characterizes these subjects’performance. Results from a category fluency task show that whereas frequency sensitivity in WS is in line with controls, error patterns imply a qualitatively distinct, looser categorical organization. Regarding the much-debated issue of morphological overgeneralizations, our data suggest that frequency sensitivity cuts across the divisions proposed by dual-process theories. In general, some of the frequency effects are the same as in typically developing populations, but with a delayed pattern. Frequency may be interpreted as supporting RN, but in WS it operates with higher thresholds that might be a general processing feature of WS individuals.