Individual differences in nonlinguistic event categorization predict later motion verb comprehension.

This study probes how individual differences in early event perception predict later verb knowledge. At Time 1, when infants were 13 to 15months of age, they saw videotaped silent scenes performed by a human actor. The goal was to see whether infants could form categories of path (a figure's trajectory with respect to a ground object) and manner (how an action is performed). Infants either saw the same manner (e.g., jogging) taking place across three different paths (around, through, and behind) or saw the same path (e.g., around a tent) taking place across three different manners (running, crawling, and walking). After familiarization, either the path or the manner was changed and visual fixation was monitored using preferential looking. At Time 2, the same children were tested on their comprehension of verbs in a two-choice pointing task showing two simultaneous actions (e.g., running vs. jumping). Success at categorization of path and manner at Time 1 predicted verb comprehension at Time 2, even when taking language knowledge at both time points into account. These preliminary results represent headway in identifying the factors that may contribute to children's language learning. They suggest that skill in categorizing semantic components present in nonlinguistic events is predictive of children's later verb vocabulary.