Language level predicts perceptual categorization of complex reversible events in children Item

Abstract. Language plays a well-documented role in object categorization, but little is known about its role in the perceptual categorization of complex events. We explored this here both with a perspective from immature language capacities in neurotypical children between the ages of two and four years (N=21), and from the viewpoint of delayed language development in a clinical group of children (N=20) with verbal mental ages (VMA) that often fell far below their chronological ages (CAs). All participants watched two demonstrations of a series of transitive events (e.g. tiger jumps over girl). The toy agents were then moved out of sight, and participants had to act out the same event type, based on a different tiger and girl, which were selected among two distractors. We aimed to determine how mastery of this task relates to CA in the neurotypical group, and whether task performance in the clinical group was predicted by VMA and a standardized measure of grammatical comprehension. Results from a series of logistic mixed-effect regression models showed that neurotypical children start to perform correctly on this task with a chance of around 50% during their third year of CA but reach ceiling performance only during their fourth. A strikingly similar pattern emerged for VMA in the clinical group, despite a wide range of CAs and diagnoses. Grammatical comprehension predicted performance as well. These patterns suggest that language competence plays a role in the perceptual categorization and encoding of complex reversible events.