Aberrant multi-brain neurodynamics drive atypical social cooperation and competition in heroin use disorder: An fNIRS-based hyperscanning study.

Although social deterioration in drug addiction has been widely acknowledged clinically, little is known about altered social interactive patterns and their intra- and inter-brain neural underpinnings. The in-depth investigation into the behavioral and neural mechanisms underlying how individuals with heroin use disorder (HUD) engage in cooperation and competition-two fundamental forms of social interaction-is crucial for comprehensively characterizing atypical social interaction in HUD. We utilized functional near-infrared spectroscopy (fNIRS) hyperscanning to explore the cooperative and competitive patterns in individuals with HUD during a real-time interactive task. Compared to healthy control dyads, HUD dyads exhibited a higher error rate under both cooperative and competitive conditions. HUD participants showed reduced inter-brain synchronization (IBS) in the prefrontal cortex (PFC) and right temporoparietal junction (r-TPJ), as well as decreased PFC activation during cooperation compared to healthy controls. In contrast, both IBS and PFC activity were higher during competition than during cooperation. Critically, IBS in the r-TPJ mediated the relationship between heroin craving and cooperative performance, suggesting a potential target for neurofeedback interventions. These findings reveal impaired cooperative abilities and heightened competitive tendencies in HUD, offering translational insights for the development of targeted interventions.