Children with autism spectrum disorders display atypical development of gesture production, and gesture impairment is one of the determining factors of autism spectrum disorder diagnosis. Despite the obvious importance of this issue for children with autism spectrum disorder, the literature on gestures in autism is scarce and contradictory. The purpose of this study was to analyze gestural communication in children with autism spectrum disorder during spontaneous mother-child interaction. Participants were children with autism spectrum disorder (n = 20), Down's syndrome (n = 20), and typical development (n = 20) and their mothers. Children's mean developmental age was 24.16 months (standard deviation = 1.45 months) and did not differ across the groups. Gestural communication was analyzed with a specific coding scheme allowing a quantitative and qualitative analysis of gestural production. Results showed the following: (a) differences between autism spectrum disorder, typical development, and Down's syndrome groups in the total number of gestures produced; (b) differences between the three groups in the distribution of gesture types; and (c) specific correlations between gestural production, cognitive development, and autism severity scores. The study of gestures in autism spectrum disorder could help us to identify different phenotypes in autism and could also lead to the development of new therapies.

Gestures have a central role in speaking and thinking about spatial information. The goal of the present study is to examine the function of gestures in Williams Syndrome (WS), a genetic disorder characterized by spatial impairments and a preservation of communication. The study's subjects were 11 WS individuals and 22 typically-developing controls who performed a narrative task. We analyzed offline gesture production and its relation with language and spatial information. Compared to the control groups, WS individuals produced more representational gestures that anticipated, supplemented, or gesture-only communication. Gestures produced by WS participants serve a compensatory role particularly in representing spatial contents.

Recent theories of episodic memory (EM) posit that the hippocampus provides a spatiotemporal framework necessary for representing events. If such theories hold true, then does the development of EM in children depend on the ability to first bind spatial and temporal information? And does this ability rely, at least in part, on normal hippocampal function? We investigated the development of EM in children 2–8 years of age (Study 1) and its impairment in Williams Syndrome, a genetic neurodevelopmental disorder characterized by visuospatial deficits and irregular hippocampal function, (Study 2) by implementing a nonverbal object-placement task that dissociates the what, where, and when components of EM. Consistent with the spatiotemporal-framework view of hippocampal EM, our results indicate that the binding of where and when in memory emerges earliest in development, around the age of 3, and is specifically impaired in WS. Space-time binding both preceded and was critical to full EM (what + where + when), and the successful association of objects to spatial locations seemed to mediate this developmental process.

No abstract