Inter-brain neural mechanism and influencing factors underlying different cooperative behaviors: a hyperscanning study.

Cooperative behavior is a vital social interaction which plays a vital role in improving human survival and reproduction. However, few empirical studies have examined the differences between cooperative behaviors and the underlying neural substrates. In the present study, the brain activity of familiar dyads of the same sex was measured using functional near-infrared spectroscopy during three cooperative tasks (cooperative button-press, tangram, and Jenga tasks). We also measured the dyads' empathic abilities and personality traits to investigate the relationships between individual characteristics and neural markers. The results showed that first, there were significant differences in intra-brain activation and inter-brain synchronization among different cooperative tasks in three dimensions: social cognition, behavioral response, and cognitive processing. Second, male participants require stronger intra-brain activation to achieve the same inter-brain synchronization level as women in cooperative tasks. Third, when performing cooperative tasks involving high cognitive demands, Big Five Neuroticism may be an important predictor of neural activation in female participants. Inter-brain synchronization plays an important role in the frontal and temporoparietal junctions during interpersonal cooperation. Furthermore, this study demonstrates that mutual prediction theory is crucial for understanding the neural mechanisms of cooperative behavior.