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通过人类神经成像进行了广泛的研究。然而，很少有人知道是什么介导的个人差异性的决定，甚至更少的人知道个人的差异反应的社会奖励。与金钱奖励相反，社会奖励的享乐价值在呈现时立即被消耗。此外，社会奖励还有丰富的进化历史：人类已经进化到处理和决定社会刺激。然而，人们对人类如何处理和决定社会奖励知之甚少。因此，我提出的研究旨在利用功能性磁共振成像（fMRI）来描述社会奖励处理和涉及社会奖励的决策的神经生物学基础。受试者将被动地接受社会奖励，也将做出涉及社会奖励的决定。在第一个实验中，受试者将做出涉及延迟社会奖励的决定。在第二个实验中，受试者将做出涉及概率性社会奖励的决定。前两个实验的核心假设是，受试者对社会奖励价值的神经计量表征（即，社会奖励敏感性）将预测个体风险偏好和社会奖励折扣率的差异。该项目的最后一个实验旨在通过使用功能连接分析来研究奖励回路中的潜在功能差异，这些差异介导了社会奖励敏感性的个体差异。对最终实验的预测是，腹侧纹状体和vmPFC之间的功能连接增加，预示着社会奖励敏感性增加。总的来说，所提出的实验将通过扩展当前的决策模型来包括社会奖励，从而进一步加深我们对决策过程的理解。正常和功能失调的决策之间的区别对心理健康有重要意义，因为许多精神病理学涉及决策功能障碍。调节正常决策和个体行为差异的神经机制还没有得到很好的理解。增强对决策中个体间差异的生物学基础的理解，可能会更好地理解几种疾病和精神健康障碍的病因;因此，拟议的项目旨在描述导致这些个体差异的神经基础。

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.