Neurobiological Underpinnings of Decision Making

描述(由申请人提供)：涉及风险或延迟金钱奖励的决策的神经基础已经在人类中进行了广泛的神经成像研究。然而，人们几乎不知道是什么在决策中调节了个体的差异，更不知道个体对社会回报的不同反应。与金钱奖励不同，社会奖励的享乐价值在展示时立即被消耗掉。此外，社会奖励还有丰富的进化史：人类已经进化到处理和做出关于社会刺激的决定。然而，人们对人类如何处理和做出关于社会回报的决定知之甚少。因此，我提议的研究试图利用功能磁共振成像(FMRI)来表征涉及社会奖励的社会奖励处理和决策的神经生物学基础。受试者会被动地接受社会回报，也会做出涉及社会回报的决策。在第一个实验中，受试者将做出涉及延迟社会回报的决定。在第二个实验中，受试者将做出涉及概率社会回报的决定。前两个实验的核心假设是，受试者在腹内侧额叶皮质(VmPFC)内对社会奖励价值(即社会奖励敏感度)的神经表征将预测个体在风险偏好和社会奖励贴现率方面的差异。该项目的最终实验试图通过功能连接分析来检验奖励回路中潜在的功能差异，这些回路通过功能连接分析来调节社会奖励敏感度的个体差异。对最终实验的预测是，腹侧纹状体和vmPFC之间功能连接的增加预示着社会奖励敏感度的增加。总而言之，拟议的实验将通过将当前的决策模型扩展到包括社会奖励来进一步理解决策过程。正常决策和功能障碍决策之间的区别对心理健康有重大影响，因为许多精神病理学都涉及决策功能障碍。调节正常决策和个体行为差异的神经机制还没有被很好地理解。加强对决策过程中个体间差异的生物学基础的了解可能有助于更好地了解几种疾病和精神健康障碍的病因；因此，拟议的项目试图确定导致这些个体差异的神经基础的特征。

DESCRIPTION (provided by applicant): The neural bases of decisions involving risky or delayed monetary rewards have been studied extensively with neuroimaging in humans. However, little is known about what mediates individual variability in decisions, and even less is known about individuals' differential responses to social rewards. In contrast to monetary rewards, the hedonic value of social rewards is immediately consumed at presentation. Social rewards additionally have a rich evolutionary history: humans have evolved to process and make decisions about social stimuli. Nevertheless, very little is known about how humans process and make decisions about social rewards. My proposed research therefore seeks to characterize the neurobiological underpinnings of social reward processing and decisions involving social rewards using functional magnetic resonance imaging (fMRI). Subjects will passively receive social rewards and will also make decisions involving social rewards. In the first experiment, subjects will make decisions involving delayed social rewards. In the second experiment, subjects will make decisions involving probabilistic social rewards. The core hypothesis for the first two experiments is that subjects' neurometric representation of value for social rewards (i.e., social reward sensitivity) within ventromedial prefrontal cortex (vmPFC) will predict individual differences in risk preferences and discounting rates for social rewards. The final experiment of the project seeks to examine the underlying functional differences in the reward circuitry that mediate individual differences in social reward sensitivity by using functional connectivity analyses. The prediction for the final experiment is that increased functional connectivity between ventral striatum and vmPFC predicts increased social reward sensitivity. Collectively, the proposed experiments will further our understanding of decision making processes by extending current models of decision making to include social rewards. The distinction between normal and dysfunctional decision making has significant implications for mental health since many psychopathologies involve dysfunctions in decision making. The neural mechanisms that mediate normal decision making and individual differences in behavior are not well understood. An enhanced understanding of the biology underlying inter-individual variability in decision making may lead to a better understanding of the etiology of several diseases and disorders of mental health; therefore, the proposed project seeks to characterize the neural underpinnings that lead to these individual differences.