Acute isolation is associated with increased reward seeking and reward learning in human adolescents

Social connection, a basic human need, is vital during adolescence. How a lack of connection impactsadolescent behaviour is unclear. To address this question, we employed experimental short-termisolation with and without access to virtual social interactions (iso total; iso with media; ordercounterbalanced, both compared to a separate baseline session). Using computationalmodelling andlinear mixed-effects models, we assessed how isolation impacts self-reported loneliness, rewardseeking and reward learning in adolescents (N = 40) aged 16–19 years. Self-reported state lonelinessincreased as a function of duration of isolation. When participants had access to virtual interactions,they self-reported less state loneliness during isolation. Isolation was associated with faster decisionsto exert effort for rewards and improved reward learning. These effects were stronger in participantswho reported higher state loneliness following isolation. These results demonstrate that, inadolescents, isolation is associated with higher reward responsiveness, a key driver of motivation anddecision-making.