Linguistic and Musical Syntax Processing in Autistic and Non-Autistic Individuals: An Event-Related Potential (ERP) Study

Syntactic processing in both language and music involves combining elements-such as words or chords-into coherent structures. The Shared Syntactic Integration Resource Hypothesis (SSIRH) was introduced based on observations of similar neural responses to syntactic violations across both domains. This hypothesis suggests that difficulties in syntactic processing in one domain may result in similar challenges in the other. The current study tested the SSIRH in autism, a neurodevelopmental condition often associated with language difficulties but relatively preserved musical abilities. Thirty-one autistic and 31 non-autistic participants judged the acceptability of syntactically congruent and incongruent sentences and musical sequences while their neural responses were recorded using electroencephalography. Autistic participants exhibited a reduced and delayed P600 effect-a marker of syntactic integration-across both domains, despite achieving similar behavioral accuracy to the non-autistic group. These findings suggest parallel difficulties in syntactic processing in autism for both language and music, providing support for the SSIRH. This is the first study to directly examine real-time syntactic integration in both domains in autistic individuals, offering novel insights into cross-domain syntactic processing in autism and contributing to a deeper understanding of language and music processing more broadly.