Alcohol and the Social Brain: An Alcohol-Administration Hyperscanning Study

Objective: Alcohol's ability to boost mood in the face of stress is perhaps its most notoriously addictive property, long held by researchers to be of critical importance for understanding alcohol use disorder (AUD) etiology. Yet, while most real-world alcohol consumption occurs in social settings, in the context of laboratory studies, participants have almost always consumed alcohol alone. The discrepancy between real-world and laboratory contexts emerges as particularly stark in the neuroimaging literature, where no alcohol-administration study to date has incorporated in-vivo social context. In this first alcohol-administration study to leverage EEG hyperscanning methods, the investigators aim to capture inter- and intra-brain mechanisms underlying alcohol reward in novel social context. Specifically, this study aims to characterize the mechanisms driving social reward from alcohol in the context of stress and elucidate the role of social processes and novel social context in driving problem drinking. Study Population: Participants will consist of 240 regular drinkers, aged 21-30, with no reported history of severe alcohol use disorder. Design: In the laboratory arm of the study, individuals will be randomly assigned to consume either a moderate dose of alcohol or a control beverage in stranger dyads. Participants will engage in both structured and unstructured tasks aimed at assessing social engagement and threat sensitivity. EEG and ERP data will be collected from both participants simultaneously. In the ambulatory study arm, participants will wear transdermal sensors to assess BAC and will further provide information about their mood and their social contexts in response to random prompts. Outcome Measures: Primary outcome measures include EEG measures of inter-brain entrainment as well as ERP metrics derived from task contexts (both players and observers). Additional outcomes include measures of positive mood, negative mood, and social bonding. Finally, drinking behaviors will be assessed via transdermal ambulatory alcohol sensors and longitudinal self-reports of drinking.