Early-life adversity, dopamine, and decision-making processes

个体寻求生存和繁衍所必需的奖赏，如食物、水、住所和配偶。 然而，必须做出许多决定，这些奖励收集奖励的时间，不同类别的奖励之间的选择，以及类别内的选择。这些过程异常复杂，因为它们整合了自我平衡和情感状态、计划以及以前学到的东西。通过工具性学习，个人学会如何获得这些奖励。然而，其他过程，如巴甫洛夫条件反射也会影响这些过程。巴甫洛夫条件刺激可以改变动机状态，促进工具性学习。事实上，许多实验研究已经研究了巴甫洛夫条件反射如何促进工具性学习和表现。然而，在现实生活中有许多情况下，巴甫洛夫刺激与目标导向行为和工具性学习相冲突。这些巴甫洛夫工具冲突在心理和神经生物学水平上知之甚少。事实上，很少有研究调查这些现象。大脑多巴胺（DA）系统，涉及中脑DA核团以及它们的下游投射部位（腹侧和背侧纹状体），参与巴甫洛夫学习和工具学习。这些DA系统可以被各种经验改变，特别是在发展过程中与主要奖励的不一致（例如，食物、父母照顾、社会接触等）。我的研究计划（长期）的总体目标是了解早期生活中的逆境（例如，社会隔离）改变大脑DA系统，以及这些变化如何反过来改变学习和决策过程。有了这个具体的建议（短期目标），我们的工作假设是，早期的逆境增加了巴甫洛夫线索的激励价值，使他们不可抗拒，并有过度的控制行为，并导致赤字的工具性学习和性能。具体来说，我们将有三个目标：* 表征早期逆境如何改变激励显着性归因于巴甫洛夫线索，以及这些，反过来，如何改变在工具性学习任务的性能 * 确定巴甫洛夫工具性冲突中涉及的神经生物学底物 * 表征DA神经传递后，早期逆境，在巴甫洛夫工具性冲突的情况下。* 本研究计划的每个部分都对总体目标做出了独特的贡献，但它们都有一个共同的和新颖的概念框架。这项研究计划的结果将揭示在冲突的动机情况下决策过程的心理学和神经生物学。

Individuals seek rewards essential for survival and procreation, such as food, water, shelter, and mates. Yet numerous decisions have to be made about these rewards timing of collecting rewards, choice between different classes of rewards, as well as within category choices. These processes are exceptionally complex as they integrate homeostatic and affective states, plans', as well as what has previously been learned. Through instrumental learning individuals learn how to obtain these rewards. However, other processes, such as Pavlovian conditioning can influence these processes as well. Pavlovian conditioned stimuli can alter motivational states and facilitate instrumental learning. In fact, numerous experimental studies have investigated how Pavlovian conditioning can facilitate instrumental learning and performance. However, there are many real-life situations in which Pavlovian stimuli are in conflict with goal-directed behaviour and instrumental learning. These Pavlovian-instrumental conflicts are poorly understood at the psychological and neurobiological levels. In fact, there are very few studies that have investigated these phenomena.***Brain dopamine (DA) systems, involving both midbrain DA nuclei as well as their downstream projections sites (ventral and dorsal striatum), are involved in both Pavlovian and instrumental learning. These DA systems can be altered by various experiences, especially by inconsistencies with primary rewards during development (e.g., food, parental care, social contact etc.). The overall objectives of my research program (long-term) are to understand how early-life adversities (e.g., social isolation) alter brain DA systems and how in turn these changes alter learning and decision-making processes. With this specific proposal (short term objectives), our working hypothesis is that early adversity increases the incentive value of Pavlovian cues, rendering them irresistible and having inordinate control over behaviour, and leading to deficits in instrumental learning and performance. Specifically we will have three objectives:*** To characterize how early adversity alters the attribution of incentive salience to Pavlovian cues and how these, in turn, alter performance in instrumental learning tasks*** To identify the neurobiological substrates involved in Pavlovian-instrumental conflicts*** To characterize DA neurotransmission following early adversity, in Pavlovian-instrumental conflict situations. ***Each segment of this research program contributes uniquely to the overall objective but they all share a common and novel conceptual framework. The results of this research program will shed light on the psychology and neurobiology of decision-making processes in conflicting motivational situations.**