Anatomical Differences in the Mirror Neuron System and Social Cognition Network in Autism

TLDR

Autism spectrum disorder is a neurodevelopmental condition marked by impaired social and emotional skills, yet its anatomical basis remains unclear. The study compared 14 high‑functioning ASD adults to matched controls and applied an automated cortical‑thickness analysis to assess regional gray‑matter differences. Results revealed cortical thinning in mirror‑neuron system regions that correlated with symptom severity and also in areas linked to emotion recognition and social cognition, indicating that these deficits may stem from abnormal cortical thinning.

Abstract

Autism spectrum disorder (ASD) is a neurodevelopmental disorder associated with impaired social and emotional skills, the anatomical substrate of which is still unknown. In this study, we compared a group of 14 high-functioning ASD adults with a group of controls matched for sex, age, intelligence quotient, and handedness. We used an automated technique of analysis that accurately measures the thickness of the cerebral cortex and generates cross-subject statistics in a coordinate system based on cortical anatomy. We found local decreases of gray matter in the ASD group in areas belonging to the mirror neuron system (MNS), argued to be the basis of empathic behavior. Cortical thinning of the MNS was correlated with ASD symptom severity. Cortical thinning was also observed in areas involved in emotion recognition and social cognition. These findings suggest that the social and emotional deficits characteristic of autism may reflect abnormal thinning of the MNS and the broader network of cortical areas subserving social cognition.