A PRISMA Systematic Review of Hyperscanning in Autism

Background Hyperscanning captures interpersonal neural synchrony (INS) during social interaction. Objective To determine whether reduced INS characterizes autism spectrum disorder (ASD) or elevated autistic-like traits (ALTs). Methods A PRISMA search (updated April 25th, 2025) screened 1552 records; 20 studies met inclusion. Quality was appraised with modified CASP checklists. Results Sixteen interpersonal analyses across 20 studies (15 ASD, five trait-based) using varied neuroimaging modalities reported attenuated synchrony in 14 cases when an autistic or high-trait partner was present; effect direction varied with task design and dyad composition, indicating methodological contingencies rather than a uniform deficit. Heterogeneity precluded meta-analysis. Conclusions Reduced INS is a robust yet context-dependent correlate of autistic characteristics. Future work should directly test task- and dyad-level moderators.