Autistic traits modulate social synchronizations between school-aged children: insights from three fNIRS hyperscanning experiments

The current study investigated how autistic traits modulate peer interactions using functional near-infrared spectroscopy (fNIRS) hyperscanning. Across three experiments, we tested the effect of co-presence, joint activity, and a tangible goal during cooperative interactions on IBC between 9-to-11-year-old children. Twenty-three dyads of children watched a video alone or together in Experiment 1, engaged in a joint or self-paced book reading in Experiment 2, and pretended to play a Jenga game or played for real in Experiment 3. Our results found that all three formats of social interactions increased inter-brain coherence (IBC) in the fronto-temporoparietal networks, which have been reported to support social interaction. Further, our results revealed the shared and unique inter-brain connections that were predictive of the lower and higher parent-reported AS-Q scores, which indicated child autistic traits. Results from a convergence of three experiments provide the best evidence to date that IBC is modulated by child autistic traits.