Lexical production in children with Williams syndrome: spontaneous use of gesture in a naming task.

This study investigates lexical organization and lexical retrieval in children with Williams syndrome (WS), by examining both naming accuracy and accompanying use of gestures in a picture-naming task. Ten children with the genetic disorder of Williams syndrome (age range: 9.5-12.9) were compared with 20 typically developing children, 10 matched for chronological age (CA) and 10 for mental-age (MA). Lexical production was measured by administering the Boston Naming test (BNT). Older typically developing children performed significantly better than the other two groups. No differences in accuracy were found between the children with WS and the typically developing children matched for mental-age. The overall distribution of error types displayed by children with WS indicate that the lexical-semantic organization is similar to that of typically developing children. However, compared to controls, the WS group produced more iconic gestures during the task, in patterns that suggest the existence of specific word-finding difficulties in these children. Results are discussed within the framework of recent theories on the role of gesture in speech production.