Abstract
Background: Previous research has emphasized the importance of gesture in early communicative development. These studies have reported that gestures are used frequently during the first two years of life and may play a transitional role in the language acquisition process. Although there are now numerous descriptions of the relationship between gesture and the developing language system in typically-developing (TD) children, relatively little is known about the nature and early development of the gesture-language system in children with developmental disorders involving specific profiles of language delay and/or impairment. Primary objective: The aim of this study is to compare early word and gesture use in children with DS and in typically-developing children to investigate potential differences in the relationship between gestural and verbal communication in early language development. Methods and Procedures: Ten children from upper-middle class families participated in the study. The five children with DS (3 boys and 2 girls) had an average chronological age of 47.6 months, an average mental age of 22.4 months, and an average language age of 18 months. Each child with DS was matched to a typically developing child on the basis of gender, language age, and observed expressive vocabulary size. Children were videotaped for 30 minutes as they interacted spontaneously with their mothers. All communicative and intelligible gestures and words produced by the children were transcribed from the videotapes. Data analyses focused on: a) overall production of gestures and words (i.e., gesture and word tokens); b) the size of children's gestural and verbal repertoires (i.e., gesture and word types); and c) production and informational content of gesture-word combinations. Main outcomes and results: Although children with DS had significantly smaller gestural repertoires than their language age-matched peers, there was no reliable difference between the two groups in the overall use of gesture. In addition, with DS produced two-element combinations (primarily gesture-word combinations) and did so at a rate comparable to that observed among their TD counterparts. However, no two-word combinations were observed among children with DS, and there were also group differences in the information contained in children's gesture-word combinations. Conclusions: Taken together, these findings suggest that in addition to the well-documented global delays in early communicative development, children with DS may exhibit additional pockets of delay, specifically in making the transition from one- to two-word speech. Results are further discussed in terms of their implications for understanding the organization of the developing gesture-language system and for the assessment of gesture in young children with communicative delays and disorders.