Contribution of working memory to gesture production in toddlers

Abstract

Starting as early as 10 months of age, gesturing is present in the communicative repertoire of children, and later, around the age of two, it is integrated with speech, yielding multimodal utterances. However, children's propensity to gesture varies, and the mechanisms underlying these individual differences remain unknown. The present study tests whether gesture production in the presence of speech (bimodal gestures) or in the absence of speech (unimodal gestures) is predicted by working memory and articulation performance associated with verbal processing. Children aged 22-46 months were presented with a gesture elicitation task in which they needed to correct the actions of a puppet using everyday objects in an unconventional way. Working memory was measured by the Imitation Sorting Task (IST) and articulation performance was indexed by the Non-Word Repetition Task (NWR). It was revealed that any increase in working memory capacity was linked to a higher incidence rate of gesturing in toddlers and working memory was differentially associated with the production of unimodal and bimodal gestures. When gestures were produced without speech, they primarily relied on attentional processes as indicated by working memory capacity. Conversely, when gestures were produced with speech, it was the articulation performance supporting speech processing that predicted the number of bimodal gestures. Overall, unimodal and bimodal gestures seem to have different working memory demands.