Visuospatial memory, gesture imitation, and gesture-supported sentence comprehension in children with developmental...

Developmental language disorder (DLD) is characterised by persistent difficulties in language acquisition and processing and often co-occurs with weaknesses in nonverbal functioning. The present study examined two task-relevant nonverbal abilities, visuospatial memory and gesture imitation, and investigated whether gesture-supported input influences sentence comprehension in children with DLD relative to typically developing (TD) peers. Forty Mandarin-speaking children (20 with DLD, 20 TD) completed a visuospatial memory task, a gesture imitation task, and a sentence comprehension task administered under gesture-supported and non-gesture conditions. A subset of 30 children also participated in an event-related potential (ERP) experiment during the comprehension task. Children with DLD performed more poorly than TD peers on visuospatial memory and gesture imitation. At the behavioural level, gesture-supported input was associated with higher comprehension accuracy and faster response times in both groups, with a larger facilitative pattern observed in the DLD group. Correlational analyses further showed that stronger visuospatial memory and gesture imitation were associated with better comprehension, particularly under gesture-supported conditions and especially among children with DLD. At the neurophysiological level, both groups showed N400 sensitivity to semantic congruency, but the DLD group exhibited attenuated neural responses and reduced modulation by gesture support. Taken together, the findings indicate systematic associations among visuospatial memory, gesture imitation, and gesture-supported sentence processing in DLD. They further suggest that gesture support may facilitate comprehension, although the behavioural and ERP patterns point to less efficient neural integration in children with DLD.