Learn from your competitor or cooperator? A hyperscanning functional near-infrared spectroscopy study of...

Social learning, a critical mechanism for human adaptation to complex societal environments, hinges not only on learners' cognitive and emotional processes but also on modes and contexts of social interaction. However, the exact mechanisms by which these factors impact social learning, and how gender differences modulate this process, remain unclear. This study employed a dual-player version of the Iowa Gambling Task, where participants alternated selecting decks under cooperative or competitive conditions. Neural signals from the right prefrontal cortex and right temporoparietal junction were captured using functional near-infrared spectroscopy equipment. Results indicated more safe decks but less frequent switching between decks in the cooperative than the competitive context. Participants reported more positive learning experiences in cooperation condition. We found higher intra-brain activation during observation than during direct reaction. Additionally, as an observer, the loss of a competitor triggered greater activation. Stage changes were observed in intra-brain activation and inter-brain synchronization (IBS), revealing gender differences in the stage effect on activation, and opposite effects on time-aligned and time-lagged IBS. Furthermore, gender-specific trends emerged, with males exhibiting higher IBS in competition and females showing higher IBS in cooperation. This study reveals dynamic neuroadaptive reconfigurations in cross-brain connectivity throughout the learning trajectory.