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

Abstract

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 eventrelated 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.