The Electrophysiology of Semantic Processing in Individuals with Autism Spectrum Disorder: A Meta-Analysis

Language difficulties vary widely among people with autism spectrum disorder (ASD). However, the semantic processing of autistic person and its underlying electrophysiological mechanism are still unclear. This meta-analysis aimed to explore the disturbance of semantic processing in patients with ASD. PubMed, Web of Science, and Embase were searched for event -related potential (ERP) studies on semantic processing in autistic people published in English before September 01, 2022. Pooled estimates were calculated by fixed-effects or random-effects models according to the heterogeneity using Comprehensive Meta-Analysis 2.0. The potential moderators were explored by meta-regression and subgroup analysis. This meta-analysis has been registered at the Prospero International Prospective Register of Systematic Reviews (no. CRD 42021265852). A total of 14 articles and 18 studies, including 254 autistic people and 262 neurodevelopmental people were included in this meta-analysis. Compared to the comparison group, autistic people showed an overall reduced N400 amplitude (Hedges' g = 0.350, p < 0.001) in response to linguistic stimuli instead of non-linguistic stimuli. The N400 amplitude was affected by verbal intelligence and gender. The reduced overall N400 amplitude in autistic people under linguistic stimuli suggests a linguistic-specific deficit in semantic processing in individuals of autism. The decrease of N400 amplitude might be a promising indication of the pool language capacity of autism.