Neurophysiology underlying neural representations of value

描述（由申请人提供）：对情绪过程的灵活调节是正常适应行为的标志。也就是说，同样的刺激或行为可以在一种情况下引起积极的情绪反应，但在另一种情况下引起消极的情绪反应。一般来说，刺激或行动可以通过经验获得情感意义。受试者了解到，先前的“中性”刺激或行为预示着有益或厌恶的事件。因此，刺激的动机意义或“价值”可以通过这种经验而改变。在这里，价值可以有正价也可以有负价。对这些刺激的情绪反应可能在很大程度上基于价值的表现。这项资助旨在探索大脑调节对习得刺激的价值表征的机制。可能参与执行这些过程的大脑结构包括杏仁核和前额皮质，杏仁核长期以来被认为是协调情绪反应的关键结构，前额皮质包含两个与杏仁核紧密相连的大脑区域：前扣带皮层和眶额皮质。这些前额叶区域被认为赋予了快速情绪调整所需的灵活调节类型。在这项资助中，我们将研究两种不同的方式来调整刺激和/或行动的价值。在目标1中，我们将研究杏仁核和前扣带皮层在逆向学习过程中的作用，即先前学习的两种刺激的关联逆转（或转换）。在我们之前研究杏仁核与OFC关系的基础上，我们将在这项任务中描述杏仁核处理和ACC之间的关系。在目标2中，我们将使用两个不同的任务来研究受试者如何通过知道如何应用规则来调整他们对刺激值的表征。在一个任务中，实验对象不需要操作动作，但强化传递确实遵循规则。在第二项任务中，被试必须按照规则执行正确的操作动作以获得强化。第二个任务旨在阐明前扣带皮层与眼窝额叶皮层和杏仁核相比的不同作用，因为前扣带皮层在动作评估、错误监测和随后的行为调整中发挥着重要作用。这项工作与理解在许多精神疾病（如情绪和焦虑障碍以及精神分裂症）中功能失调的神经回路直接相关。在这些疾病中，杏仁核-前额叶回路的功能障碍可能会损害情绪的类型

DESCRIPTION (provided by applicant): The flexible regulation of emotional processes is a hallmark of normal adaptive behavior. To wit, the same stimulus or action can elicit a positive emotional response in one situation, but a negative one in another situation. In general, stimuli or actions can acquire affective meaning through experience. Subjects learn that previously "neutral" stimuli or actions predict rewarding or aversive events. Thus the motivational significance, or "value", of stimuli can be changed by virtue of this experience. Here, value can have either positive or negative valence. Emotional responses to these stimuli may be based in large part on the representation of value. This grant explores the mechanisms by which the brain adjusts representations of the value of learned stimuli. Brain structures likely to participae in implementing these processes include the amygdala, long recognized as a critical structure in coordinating emotional responses, and the prefrontal cortex, which contains two brain areas densely interconnected with the amygdala: the anterior cingulate and orbitofrontal cortices. These prefrontal areas are thought to confer the type of flexible regulation required for rapid emotional adjustments. In this grant, we will study two different ways in which the value of stimuli and/or actions may be adjusted. In Aim 1, we will study the role of the amygdala and anterior cingulate cortex in a reversal learning procedure, whereby the previously learned associations of two stimuli reverse (or switch). We will characterize the relationship between processing in the amygdala and ACC during this task, building on our prior work studying the amygdala's relationship with OFC. In Aim 2, we will use two different tasks to study how subjects can adjust their representation of the value of a stimulus by knowing how to apply a rule. In one task, no operant actions are required of the experimental subjects, but reinforcement delivery does follow rules. In the second task, subjects must perform the correct operant action according to a rule in order to obtain reinforcement. The second task was designed to elucidate the differential role of the anterior cingulate cortex, as compared to the orbitofrontal cortex and amygdala, as the anterior cingulate has been proposed to play a prominent role in action valuation, error monitoring, and subsequent adjustments of behavior. This work has direct relevance to understanding the neural circuitry that becomes dysfunctional in many psychiatric disorders, such as mood and anxiety disorders, as well as schizophrenia. In those disorders, dysfunction in amygdala- prefrontal circuitry likely impairs the type of emotional flexibility required for normal mental health.