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.

先前的研究强调了动机系统在风险决策中的重要性，但动机的个体差异可能影响青少年冒险行为的机制仍有待确定。基于发展神经科学文献表明风险处理在解释基于价值的决策中的个体差异方面的重要性，我们研究了风险处理作为特质动机与青少年冒险行为之间关联的潜在中介因素。样本由 167 名青少年（47% 为女性）组成，每年进行为期三年的评估（时间 1 为 13-14 岁）。使用青少年自我报告来衡量接近和回避动机。风险偏好是根据青少年在修改后的经济彩票选择任务中的决定来估计的，神经风险处理是通过双侧岛叶皮层对所选选项的血氧水平依赖性反应来测量的。使用红绿灯任务通过基于实验室的风险决策来评估青少年的冒险行为。纵向中介分析揭示了接近动机的显着间接影响，例如，在风险处理过程中，通过减少双侧岛叶皮层的神经激活，较高的动机与冒险行为的增加相关。研究结果说明了一条神经通路，通过该通路动机转化为冒险发展的脆弱性。