Real-time interpersonal conflict and neural synchronization: An fNIRS hyperscanning study using an interactive Greedy...

Interpersonal conflict is a ubiquitous social interaction phenomenon, yet its underlying neural mechanisms remain underspecified within cognitive-neuroscientific frameworks. Guided by the disagreement-interference-negative affect triad, we re-engineered the classic Greedy Snake game to establish two real-time interactive paradigms (Conflict vs. Non-Conflict), thereby operationalizing conflict. Using functional near-infrared spectroscopy hyperscanning (fNIRS-hyperscanning), we recorded hemodynamic responses from 52 university student dyads (N = 104) during task execution. After excluding data that did not meet quality standards, 44 dyads were included for neural analysis. Behaviorally, the Conflict paradigm significantly amplified subjective perceptions of goal incongruence and mutual interference, and elicited antagonistic behavior as evidenced by reduced monetary reward allocation, effectively validating the experimental manipulation. Neurally, compared with the Non-Conflict group, the Conflict group elicited stronger oxygenated hemoglobin (HbO) responses in the left inferior frontal gyrus (lIFG), dorsolateral prefrontal cortex (dlPFC), and right temporoparietal junction (rTPJ), with higher inter-brain synchrony (IBS) in these regions. These findings suggest that interpersonal conflict necessitates coordinated cognitive processes, including action observation, cognitive control, and social inference. This study provides novel evidence for multi-brain coordination mechanisms during interpersonal conflict, offering a robust methodological and theoretical framework for social neuroscience.