Social-cognitive brain function and connectivity during visual perspective-taking in autism and schizophrenia.

BACKGROUND

Autism spectrum disorder (ASD) and schizophrenia are neurodevelopmental conditions that are characterized by significant social impairment. Emerging genomic and neurobiological evidence has increasingly pointed to shared pathophysiologic mechanisms in the two disorders. Overlap in social impairment may reflect similar underlying neural dysfunction in social-cognitive brain networks, yet few studies have directly compared brain function and communication between those with ASD and schizophrenia.

METHODS

Outpatients with schizophrenia (n=36), ASD (n=33), and healthy volunteers (n=37) completed a visual perspective-taking task during functional neuroimaging at 3T to assess similarities and differences in fronto-temporal brain function and connectivity during social-cognitive processing. Analyses employed general linear models to examine differences in amplitude of BOLD-signal response between disorder groups, and computed functional connectivity coefficients to investigate differences in the connectivity profiles of networks implicated in social cognition.

RESULTS

Despite similar behavioral impairments, participants with ASD and schizophrenia evidenced distinct neural abnormalities during perspective-taking. Functional activation results indicated reduced temporo-parietal junction and medial prefrontal activity in ASD compared to schizophrenia (all P<0.002). Functional connectivity analyses further revealed significantly greater local orbitofrontal connectivity in ASD than schizophrenia (all P<0.028) during perspective-taking. Differences in brain activation and connectivity were unrelated to antipsychotic medication dose.

CONCLUSIONS

Autism and schizophrenia are characterized by similar social-cognitive impairments that may stem from different underlying abnormalities in the functional organization and communication of the social brain.