Department of Developmental and Educational Psychology, Institute of Psychology, Leiden University, The Netherlands; Leiden Institute for Brain and Cognition, The Netherlands.
Department of Developmental and Educational Psychology, Institute of Psychology, Leiden University, The Netherlands; Leiden Institute for Brain and Cognition, The Netherlands.
Neuroimage. 2018 May 15;172:663-673. doi: 10.1016/j.neuroimage.2018.01.085. Epub 2018 Feb 3.
Although many neuroimaging studies have investigated adolescent risk taking, few studies have dissociated between decision-making under risk (known probabilities) and ambiguity (unknown probabilities). Furthermore, which brain regions are sensitive to individual differences in task-related and self-reported risk taking remains elusive. We presented 198 adolescents (11-24 years, an age-range in which individual differences in risk taking are prominent) with an fMRI paradigm that separated decision-making (choosing to gamble or not) and reward outcome processing (gains, no gains) under risky and ambiguous conditions, and related this to task-related and self-reported risk taking. We observed distinct neural mechanisms underlying risky and ambiguous gambling, with risk more prominently associated with activation in parietal cortex, and ambiguity more prominently with dorsolateral prefrontal cortex (PFC), as well as medial PFC during outcome processing. Individual differences in task-related risk taking were positively associated with ventral striatum activation in the decision phase, specifically for risk, and negatively associated with insula and dorsomedial PFC activation, specifically for ambiguity. Moreover, dorsolateral PFC activation in the outcome phase seemed a prominent marker for individual differences in task-related risk taking under ambiguity as well as self-reported daily-life risk taking, in which greater risk taking was associated with reduced activation in dorsolateral PFC. Together, this study demonstrates the importance of considering multiple risk-taking measures, and contextual moderators, in understanding the neural mechanisms underlying adolescent risk taking.
虽然许多神经影像学研究都探讨了青少年的冒险行为，但很少有研究能够区分风险下的决策（已知概率）和模糊性下的决策（未知概率）。此外，哪些大脑区域对与任务相关的和自我报告的风险承担的个体差异敏感仍然难以捉摸。我们向 198 名青少年（11-24 岁，这个年龄段的风险承担差异显著）展示了一个 fMRI 范式，该范式将风险（选择赌博或不赌博）和奖励结果处理（收益、无收益）在风险和模糊条件下分开，并将其与与任务相关的和自我报告的风险承担相关联。我们观察到冒险和模糊赌博的神经机制不同，风险更明显与顶叶皮层的激活有关，而模糊性更明显与背外侧前额叶皮层（PFC）以及结果处理期间的内侧前额叶皮层（MPFC）有关。与任务相关的风险承担的个体差异与决策阶段的腹侧纹状体激活呈正相关，特别是与风险相关，与岛叶和背内侧前额叶皮层（DM PFC）的激活呈负相关，特别是与模糊性相关。此外，结果阶段的背外侧前额叶皮层的激活似乎是模糊性下与任务相关的风险承担以及自我报告的日常生活风险承担的个体差异的一个突出标志物，其中更大的风险承担与背外侧前额叶皮层的激活减少有关。总之，这项研究表明，在理解青少年冒险行为的神经机制时，考虑多种风险承担措施和情境调节因素非常重要。
