Background: Fragile X syndrome (FXS) and Down syndrome (DS) are the two leading genetic causes of intellectual disability, and FXS is the most common known genetic condition associated with autism. Both FXS and DS are associated with significant language impairment, but little is known about expressive language across domains over time or the role…

The autistic impairments in emotional and social competence, imagination and generating ideas predict qualitative differences in expressive drawings by children with autism beyond that accounted by any general learning difficulties. In a sample of 60 5-19-year-olds, happy and sad drawings were requested from 15 participants with non-savant autism…

Individuals with Down syndrome (DS) tend to have impaired verbal short-term memory (STM), which persists even when visual support is provided for carrying out verbal tasks. Objective: The current study aims to investigate whether visuospatial support, rather than just visual, can compensate for verbal STM deficits in these individuals. The…

Adults with autism spectrum disorders (ASD) have shown deficits in switching between rules governing their behaviour, as have high-functioning children with ASD. However, there are few studies of flexibility in lower-functioning children with ASD. The current study investigated this phenomenon with a group of low-functioning children with ASD…

Background: Although there is growing awareness about the potential for people with Down syndrome (DS) to become literate, we know little about the characteristics of handwriting within this population. Methods: Thirty-three participants took part in this experiment. Eleven adults with DS and 22 typically developing individuals (11 children…

The aim of this study was to compare the prosodic profiles of English- and Spanish-speaking children with Williams syndrome (WS), examining cross-linguistic differences. Two groups of children with WS, English and Spanish, of similar chronological and nonverbal mental age, were compared on performance in expressive and receptive prosodic tasks…

Aberrant attention is a core feature of fragile X syndrome (FXS), however, little is known regarding the developmental trajectory and underlying physiological processes of attention deficits in FXS. Atypical visual attention is an early emerging and robust indicator of autism in idiopathic (non-FXS) autism. Using a biobehavioral approach with gaze…

Language profiles of children with autistic disorder and intellectual disability (n = 36) were significantly different from the comparison groups of children with intellectual disability (n = 26) and typically developing children (n = 34). The group low-functioning children with autistic disorder obtained a higher mean score on expressive than on…

This study compared mothers and fathers' regulation with respect to 29 children with intellectual disability (ID) and 30 typically developing (TD) children, matched on their mental age (MA), as they solved eight tasks using physical materials and computers. Seven parents' regulatory strategies were coded as they supported their child's…

In order to examine the roles of mental age, social interaction, and communication in self-representation abilities, typically-developing children were compared with children with Autism Spectrum Disorders. Typically-developing children (TD, n = 66) and children with Autism Spectrum Disorders (ASD, n = 20), including subgroups of autistic disorder…

Everyday memory and its relationship to working memory was investigated in adolescents with mild intellectual disability and compared to typically developing adolescents of the same age (CA) and younger children matched on mental age (MA). Results showed a delay on almost all memory measures for the adolescents with mild intellectual disability…

The emergence of the Down syndrome (DS) behavioural phenotype during early development may be of great importance for early intervention. The main goal of this study was to investigate the good-imitator-poor-talker developmental profile in DS at preschool age. Twenty children with Down syndrome (DS; mean nonverbal mental age NMA 1 y10 m) and 15…

Individuals with Williams syndrome display indiscriminate approach towards strangers. Neuroimaging studies conducted so far have linked this social profile to structural and/or functional abnormalities in WS amygdala and prefrontal cortex. In this study, the neuropsychological hypotheses of amygdala and prefrontal cortex involvement in WS…

(Purpose) The purpose of this research model is to determine if a gifted preschool child will be less likely to experience severe emotional disturbance (SED) if he, or she, has been exposed to a curriculum that is appropriate for his, or her, mental age and an environment with true peers that is appropriate for his, or her, chronological age. …

Williams Syndrome (WS) is a developmental disorder typified by deficits in visuospatial cognition. To understand the nature of this deficit, we characterized how people with WS perceive visual orientation, a fundamental ability related to object identification. We compared WS participants to typically developing children (3-6 years of age) and…