Abnormalities in Pattern of Lateralization in Relation to Visuospatial Short Term Memory in Children with Williams Syndrome

Antonios Chasouris,Peter Mayer,Martin Graff,Lance Workman,Ian Stuart-Hamilton

doi:10.1155/2014/491458

Antonios Chasouris, Peter Mayer + Show 3 more

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https://doi.org/10.1155/2014/491458

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Abstract

Williams syndrome (WS) is a genetic disorder characterised by significant intellectual disability. Initial studies indicate that children with WS have a profound bias for information in the top left of visual arrays. Study 1, using a visuospatial memory test for items presented in a 3×3 matrix, found a significant top left bias in WS children relative to controls. Study 2 used a probe-based memory test with arrays in which items appeared with equal probability in each position. Relative to controls, WS children showed a significant top and left bias. In Study 3, the same children engaged in a visual search task and again, a top and left bias was found in the WS group. It is concluded that children with WS display atypical laterality, which might be explained by abnormal saccadic movements, by abnormalities involving development of the dorsal stream or by uneven cortical development.

Highlights

Williams syndrome (WS) is a relatively rare genetic disorder that results in mild to severe intellectual disabilities with well-documented peaks and troughs in cognitive and socioemotional abilities
Horizontal misplacement Analysis was by mixed analysis of variance (ANOVA) using SPSS
Relative to typically developing children (TD) children, there was a leftward bias in children with WS: items positioned to the right were omitted or misplaced significantly more times than other items

Summary

Introduction

Williams syndrome (WS) is a relatively rare genetic disorder that results in mild to severe intellectual disabilities with well-documented peaks and troughs in cognitive and socioemotional abilities (see, e.g., [1]). WS children’s teachers often report that they will read the first few words on the line and move to the line, irrespective of the fact that the resulting phrase is nonsensical Whilst such anecdotal reports of a lateral bias have not been formally studied, there has been a great deal of published research demonstrating abnormalities in visuospatial processing for WS individuals. As with Experiment 1, to allow for the consideration that this might be a universal feature and not one specific to Williams syndrome, a group of mental age-matched typically developing (TD) children was used as controls. The experimental hypotheses were that (1) children with Williams syndrome would recall significantly more items from the left of the display and (2) that this bias would be significantly stronger than in typically developing children. If WS participants are able to identify targets quickly across all positions in the array, this will indicate a retrieval problem, whereas if there are significantly longer responses in the right of the display, this indicates a problem in processing

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