Longitudinal link between trait motivation and risk-taking behaviors via neural risk processing

Prior research has emphasized the importance of the motivational system in risky decision-making, yet the mechanisms through which individual differences in motivation may influence adolescents' risk-taking behaviors remain to be determined. Based on developmental neuroscience literature illustrating the importance of risk processing in explaining individual differences in value-based decision making, we examined risk processing as a potential mediator of the association between trait motivations and adolescents' risk-taking behaviors. The sample consisted of 167 adolescents (47% females) annually assessed for three years (13-14 years of age at Time 1). Approach and avoidance motivations were measured using adolescent self-report. Risk preference was estimated based on adolescents' decisions during a modified economic lottery choice task with neural risk processing being measured by blood-oxygen-level-dependent responses in the bilateral insular cortex for chosen options. Adolescents' risk-taking behaviors were assessed by laboratory-based risky decision making using the Stoplight task. Longitudinal mediation analyses revealed a significant indirect effect of approach motivation, such that higher motivation was correlated with increases in risk-taking behaviors via decreases in neural activation in the bilateral insular cortex during risk processing. The findings illustrate a neural pathway through which approach motivation is translated into the vulnerability to risk taking development.