The electrophysiology of semantic processing in individuals with autism spectrum disorder: A meta-analysis

Abstract

Abstract Language deficits vary widely among people with autism spectrum disorder (ASD). However, the semantic processing of autism and its underlying electrophysiological mechanism are still unclear. PubMed, Web of Science, and Embase were searched for event-related potential (ERP) studies on semantic processing in people with ASD published in English before September 1, 2022. Pooled estimates were calculated by fixed-effects or random-effects models according to the heterogeneity. The potential moderator was explored by meta-regression and subgroup analysis. This meta-analysis has been registered on PROSPERO (no. CRD 42021265852). Our study included 14 articles and 18 studies, including 254 ASD patients and 262 controls. Compared to the controls, ASD patients showed a reduced N400 amplitude (Hedges' g = 0.350, P<0.001) in response to linguistic stimuli instead of non-linguistic stimuli. The N400 amplitude can be affected by verbal intelligence and gender. The reduced overall N400 amplitude in ASD patients under linguistic stimuli suggests a linguistic-specific deficit in semantic processing in individuals of ASD. The decrease of N400 amplitude might be a promising indication of the pool language capacity of ASD.