The link between gesture and speech in children with Down syndrome

Research evidence suggests that, for typically developing children, spoken language and gesture develop alongside one another during early language development. Once children have begun to demonstrate two-word speech, there is a gradual reduction in new gesture learning and frequency of gesture use with increasing spoken language acquisition. Thus, though children do continue to use gesture, this becomes less frequent as children develop spoken language skills. The relationship between gesture and speech for children with Down syndrome is less clear. For many children with Down syndrome, speech and language skills are poor relative to their general cognitive abilities. It may be expected then, that because of these speech and language difficulties, children with Down syndrome are more reliant on gesture to convey understanding. This question was the focus of a recent paper by Silvia Stefanini and colleagues. In this study, 15 children with Down syndrome (aged 3-8 years) were compared to 2 groups of typically developing children; a group matched for chronological age, and a second, younger group matched for mental age. The children were asked to name pictures, and the researchers recorded both spoken language production and gestural production during the task. When children were compared on their spoken accuracy, children with Down syndrome produced fewer correct and more incorrect spoken responses than the typically developing children. Closer inspection of verbal responses highlights the speech articulation difficulties of the children with Down syndrome: many correct answers were phonologically altered and many incorrect answers were unintelligible productions. Analysis of gestural production showed that all children used gesture, though the older typically developing children were less likely to do so than either of the other two groups, reflecting the decreasing use of gesture with increasing spoken language competence previously noted in typically developing groups. Children with Down syndrome gestured more frequently than the typically developing children and, in particular, were more likely to use iconic gestures. Iconic gestures are those that represent the meaning of the target picture, typically by performing the action of an object (e.g. moving fingers as though combing hair in response to “comb”). Typically developing children of the same mental-age as the children with Down syndrome also used iconic gestures, though these were often produced alongside the correct spoken answer. In this case, the gesture elaborated or added to the verbal response. In contrast, children with Down syndrome were more likely to use gesture without accompanying speech than typically developing children. Furthermore, the correct meaning of the target word could be expressed in gesture even when it was accompanied by incorrect speech. Thus, for this group, iconic gestures were often used as an aid to convey meaning. Including gestures which correctly conveyed the target meaning into the spoken accuracy data resulted in a significant increase in scores for children with Down syndrome, though accuracy was still poorer for this group than for the typically developing groups. This paper suggests that children with Down syndrome use gestures to convey conceptual understanding. For this group, linguistic abilities are typically impaired relative to cognitive abilities. Difficulties with speech and language mean that, while gestures become a less important means of communication for typically developing children as spoken language increases, for many children with Down syndrome, gestures are more efficient vehicles for demonstrating understanding than verbal expression alone. For this group then, gesture and speech interact to convey meaning. Gestures are therefore a very important means by which children with Down syndrome communicate and interact with others.