Neural Valuation of Antidrinking Campaigns and Risky Peer Influence in Daily Life

Objective: Health behavior is affected by competing sources of influence like media messages and peers. In the context of alcohol consumption, college students are targeted by antidrinking media messages, but tend to have proalcohol conversations with peers. How do humans integrate competing sources of influence on daily behavior? We observed individuals under exposure to antialcohol media messages and proalcohol conversations and tested a "common neural value"account of how contradictory influences are integrated to affect behavior. Methods: Participants were instructed to cognitively regulate responses to antidrinking media messages while undergoing fMRI at baseline. Individual differences in success in message-consistent or - derogating regulation were indexed by changes in activity within the neural valuation system (ventral striatum/VS, ventromedial prefrontal cortex/VMPFC), providing a proxy for success in finding value in message-consistent/-derogating engagement. To measure peer influence, we tracked daily drinking-related conversations and drinking behavior for 30 days using mobile electronic diaries. Results: Peer conversations, on average, were positive toward drinking. More positive conversations led to more future drinking, particularly for participants who showed greater neural value signals when derogating antidrinking media. Susceptibility to risky peer influence decreased with increasing success in up-regulating message-consistent neural valuation responses to antidrinking media. Neural effects were driven by VS-activity. Conclusions: Results are consistent with a dynamic value integration process where contradictory influences inform a common neural value signal. Reductions in the value of a behavior ( through antidrinking campaigns) may buffer against future value increases after exposure to competing influences ( proalcohol peers) with important real-world consequences.