Speech and gesture: The development of an integrated system in children with autism spectrum disorder

There is considerable evidence that speech and gesture form an integrated system in adult communication. The development of this integrated system in typically developing children has also been the focus of extensive research, especially with regard to the transition from one to two-word speech. This paper builds on this prior research, incorporating previous findings in the formation of a speech and gesture processing architecture.

This proposed architecture gives rise to a predictable developmental sequence of verbal and gestural behaviours from vocalisations, through first words to two-word speech. The behavioural sequence is investigated in children with Autism Spectrum Disorder (ASD). This is an interesting population to study for two reasons; firstly the language delay associated with ASD may mean that the onset of behaviours will be less rapid than for typically developing children, thus being clearly identifiable, and secondly there is evidence to suggest that children with ASD have difficulty in the integration of cross-modal information. Results from a limited group study suggest that development is in line with the predicted sequence of behaviours, but that children with ASD do not gain the same benefit from cross-modal integration in their communication when compared to typically developing children. Possible reasons for this finding are discussed.