The impact of alcohol on brain response in social context: A hyperscanning alcohol-administration trial

Evidence for the integration of alcohol into social life dates to the beginning of recorded history. Humans' tendency to combine social interaction with alcohol has been attributed to alcohol's ability to shift social perception, with behavioral research suggesting alcohol fosters social connection and diminishes perceived social threat. Yet the acute effects of alcohol on brain responses in social context are as yet unexplored. Combining experimental alcohol-administration with an EEG hyperscanning paradigm, the current study examines the effect of alcohol on evaluation of self- and other-linked performance. Social drinkers (N = 128) were administered either an alcoholic (target BAC 0.08 %) or control beverage in pairs. Dyads engaged in a gambling task while event-related potential Feedback Effects (FEs) to wins and losses were assessed simultaneously in both participants. Findings indicated a significant correlation in FEs among players and observers. Results further revealed alcohol effects that emerged specifically in the social domain, with alcohol intoxication significantly reducing the magnitude of FEs among observers paired with a stranger. In contrast, alcohol's impact on FEs was non-significant when participants observed a familiar partner, as well as when participants were actively engaged in playing. Taken together, findings provide evidence for core social (e.g., observational) dimensions of human cognition and further offer clues surrounding neural pathways supporting the widespread integration of alcohol into social life.