Children often answer questions when they do not have the requisite knowledge or when they do not understand them. We examined whether "ground rules" instruction--to say "I don't know," to tell the truth, and to correct the interviewer when necessary--assisted children in applying those rules during an interview about a past…

A number of studies suggest that imitation is a characteristic strength in children with Down Syndrome (DS). The present study aims to discover whether imitation performances are qualitatively phenotypical in DS. Eight preschoolers with DS were matched on chronological, mental, language and imitation age with 8 preschoolers with intellectual…

This study investigated the development of novel metaphor and metonymy comprehension in both typically developing (TD) children and individuals with Williams syndrome (WS). Thirty-one TD children between the ages of 3;09 and 17;01 and thirty-four individuals with WS between the ages of 7;01 and 44 years old were administered a newly developed task…

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…

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…

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…

Background: It is recognized that individuals with Down's syndrome have a specific deficit in verbal short-term memory. On the other hand, non-verbal short-term memory seems to be preserved or even be a strong point for these persons. Nevertheless, the extent and specificity of the deficit must be determined. To do so, we carried out a research…

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…

Examined the nature of repetitive, ritualistic, and compulsive-like behaviors in typically developing and children and individuals with Down Syndrome (DS), matched on mental age (MA). Found that that both groups showed similar MA-related changes in compulsive-like behaviors. Younger children showed more compulsive-like behaviors than older.…

Examined the relation between a history of maltreatment and cognitive control functioning in two groups of preschool and early school-age maltreated and nonmaltreated children. Maltreated children showed developmentally impaired cognitive control functioning on a number of tasks. (RH)

Forty-nine children (ages 8-17) with mental retardation recognized facial expressions less accurately than did subjects without retardation who were matched on chronological age. Mental age-matched groups showed no differences in accuracy at a younger mental age, but a difference was found at an older mental age. (Author/JDD)