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神经成像中得到了广泛的研究。然而，对于是什么导致了个体的决策差异，我们知之甚少，对于个体对社会奖励的不同反应，我们所知的就更少了。与金钱奖励相比，社会奖励的享乐价值在呈现时立即被消耗掉。此外，社会奖励具有丰富的进化历史：人类已经进化到能够处理和做出有关社会刺激的决定。然而，我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）表征社会奖励处理和涉及社会奖励的决策的神经生物学基础。受试者会被动地接受社会奖励，也会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社会奖励的决定。前两个实验的核心假设是，受试者在腹内侧前额叶皮层（vmPFC）内对社会奖励价值的神经测量表征（即社会奖励敏感性）将预测个体在风险偏好和社会奖励折现率方面的差异。该项目的最后一个实验旨在通过功能连通性分析，检查调节社会奖励敏感性个体差异的奖励回路的潜在功能差异。最后一个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性的增加。总的来说，提出的实验将通过扩展当前的决策模型来包括社会奖励，从而进一步我们对决策过程的理解。由于许多精神病理学涉及决策功能障碍，因此区分正常决策和功能障碍决策对心理健康具有重要意义。调节正常决策和个体行为差异的神经机制尚不清楚。加强对决策中个体间差异的生物学基础的理解，可能会导致对几种疾病和精神健康障碍的病因的更好理解；因此，提议的项目试图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.