Precursors of language development in ASC: A longitudinal single-subject study of gestures in relation to phonetic prosody

Abstract

We longitudinally investigated the development of deictic and general accompanying gestures in one 5-year-old boy with autism spectrum condition (ASC) and intellectual disability. The investigation was performed during an intervention focusing on phonological segments. The purpose was to see whether gestures developed in conjunction with language. We found that deictic and general accompanying gestures increased during the study, despite not being trained. There was also a positive temporal correlation between deictic gestures and speech. Contrary to the expectations in this case, declarative gestures were frequent and increased, while imperative decreased during the period of intervention. Furthermore, we detected a specific kind of general accompanying non-context-sensitive gestures that may be involved in the retrieval of phonemes and syllables. Speech prosody was also analysed in relation to these gestures.