Body-part categories of early-learned verbs: Different granularities at different points in development

This paper builds on our previous finding that early verbs are strongly related to body parts. One evidence for this relation is the strong word associations among adults between common verbs and body parts. Although many common verbs are related to body parts, the prior evidence suggests that some verbs are strongly related to highly specific body regions (e.g., fingers) and others to larger or more diffuse regions (e.g., hand and arm). Here we ask whether this granularity or specificity in associations is related to age of acquisition. We examine the structure of adult associations of common verbs to body parts as a function of age of acquisition for a 101 verbs normatively acquired between 16 to 30 months. And we propose a new analysis to look at the development of granularity over a short time period: 16 months and for a small number of verbs: 101. We generated verb clusters based on body parts features, and analysed how these body-partsbased clusters account for variance of age of acquisition (AoA) of verbs. By applying this analysis from the 50 earliest learned verbs to the 50 latest learned ones, we found several clusters relevant to AoA in different granularity of body parts. The results fit with growing behavioural and neuro-imaging results on the role of the body - and sensory-motor interactions in the world - in verb processing.