Altered semantic integration in autism beyond language

Abstract

Autism spectrum disorders (ASDs) are characterized by impaired communication, particularly pragmatic and semantic language, resulting in verbal comprehension deficits. Semantic processing in these conditions has been studied extensively, but mostly limited only to linguistic material. Emerging evidence, however, suggests that semantic integration deficits may extend beyond the verbal domain. Here, we explored cross-modal semantic integration using visual targets preceded by musical and linguistic cues. Particularly, we have recorded the event-related potentials to evaluate whether the N400 and late positive potential (LPP) components, two widely studied electrophysiological markers of semantic processing, are differently sensitive to congruence with respect to typically developing children. Seven ASD patients and seven neurotypical participants matched by age, education and intelligence quotient provided usable data. Neuroelectric activity was recorded in response to visual targets that were related or unrelated to a preceding spoken sentence or musical excerpt. The N400 was sensitive to semantic congruence in the controls but not the patients, whereas the LPP showed a complementary pattern. These results suggest that semantic processing in ASD children is also altered in the context of musical and visual stimuli, and point to a functional decoupling between the generators of the N400 and LPP, which may indicate delayed semantic processing. These novel findings underline the importance of exploring semantic integration across multiple modalities in ASDs and provide motivation for further investigation in large clinical samples.

Developmental differences in neural connectivity for semantic processing in youths with autism

“…The less IFG activation found in ASD youths during retrieval/selection of semantic knowledge (Chen, Gau, Lee, & Chou, 2016) suggests that they show the lower engagement of mechanisms involved in cognitive control required for higher-level comprehension. Event-related potentials (ERP) research demonstrates that the N400 effect important for semantic integration is reduced or absent during lexicosemantic processing in individuals with ASD compared to TD individuals, reflecting an impairment at the word and the sentence level understanding (Coderre, Chernenok, Gordon, & Ledoux, 2017;Megnin et al, 2012;Ribeiro, Valasek, Minati, & Boggio, 2013). Previous studies have shown that adults with ASD have impairments for both linguistic and visual narrative comprehension, suggesting that they have deficits in integrating contextual information (Coderre et al, 2018).…”

ERP evidence of semantic processing in children with ASD

“…Two studies have found altered, but not absent semantic processing in individuals with ASD. Ribeiro et al (2013) investigated semantic processing in seven children with high functioning autism, using a semantic congruency sentence task. They found that there was no N400 response in the children with ASD, but instead the conditions were differentiated by a late positive potential (LPP).…”

The Real-Time Comprehension of Idioms by Typical Children, Children with Specific Language Impairment and Children with Autism

“…A likely candidate is therefore a deficit of lexical/semantic memory, consistent with claims for low-functioning autism [ 56 ]. As well, studies of adults with autism using event-related potentials consistently report abnormalities of the N400 component [ 77 , 78 ], consistent with semantic memory dysfunction (on the interpretation of the N400 that it indexes semantic memory [ 55 ]). However, as performance with single words can be quite good in individuals with autism, and even better-than-normal in some respects [ 41 , 79 , 80 ], it may be that, at least in high-functioning autism, an idiom deficit reflects only certain aspects of semantic memory that are deficient in the disorder.…”