Exploring Hemispheric Contributions in the Processing of Social Speech in Autism

Journal article, 2025

Background: Based on the lateralization of hemispheres in certain cognitive functions and the lack of knowledge of these dimensions in autism, this study aimed to compare the contribution of hemispheres to auditory spatial attention during socially relevant speech processing in children with autism compared to their typically developing peers (TD).
Methods: The participants were 27 Romanian children, including 12 children with autism and 15 typically developing children. Auditory stimuli were simple three-word Romanian sentences presented in an oddball pattern under three listening conditions: right ear, left ear, and binaural. We extracted the P300 event-related potential (ERP) component in response to all conditions and compared the two groups. Statistical analyses were performed using multivariate analysis of variance (MANOVA) with follow-up tests for between-subject effects.
Results: Multivariate analyses showed no significant overall differences across groups in the different conditions. However, between-subjects effects tests revealed a significant reduction in P300 amplitude for the left ear condition in the Autism spectrum disorder (ASD) group compared with TD peers (p = 0.042, partial η² = 0.155). Across all conditions, latency differences were not statistically significant.
Conclusion: The selective reduction in P300 amplitude for left ear input in children with ASD indicates reduced attentional engagement with socio-semantic aspects of speech that are predominantly processed in the right hemisphere. The findings emphasize the importance of lateralization-sensitive auditory patterns in understanding and addressing communication deficits in ASD.