Neural mechanisms underlying simple and complex reinforcement learning

简单和复杂强化学习背后的神经机制

• 批准号: 7489311
• 负责人: Sara Morrison
• 金额: $ 3.51万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7489311
• 关键词: Affective; Air; Amygdaloid structure; Animals; Area; Behavior; Behavioral; Biological Assay; Blinking; Brain; Cognitive; Complex; Condition; Conditioned Stimulus; Cues; Emotional; Endogenous depression; Environment; Evaluation; Face; Functional disorder; Future; Hand; Human; Image; Individual; Knowledge; Learning; Light; Link; Liquid substance; Mental Depression; Mental disorders; Monkeys; Neurons; Organism; Outcome; Physiological; Play; Post-Traumatic Stress Disorders; Primates; Procedures; Process; Property; Psychological reinforcement; Punishment; Relative (related person); Rewards; Schizophrenia; Sensory; Signal Transduction; Stimulus; Structure; Testing; Thinking; Time; Trauma; Update; abstracting; base; behavior measurement; classical conditioning; conditioning; environmental change; executive function; experience; motivated behavior; neural circuit; neuromechanism; novel; relating to nervous system; research study; response; sensory stimulus; visual stimulus

DESCRIPTION (provided by applicant): In order to guide motivated behavior, humans and animals need to be able to flexibly evaluate the affective values - positive or negative - of stimuli in the environment. This process may go awry in psychiatric disorders; for example, in post-traumatic stress disorder (PTSD), an overly negative, inflexible value may be assigned to certain stimuli associated a trauma, even in a context where they should be non- threatening. The focus of this proposal is on how the values of stimuli are represented in the brain, and how this representation changes in response to changing environmental context. To investigate this, neural activity will be recorded simultaneously in two brain areas - the amygdala and orbitofrontal cortex (OFC) - while monkeys perform one of two tasks: a simple conditioning task, in which visual stimuli become linked with reward or punishment, and a context-dependent task, in which the meaning of visual stimuli changes from moment to moment depending upon contextual cues. The simpler task will reveal whether and how stimulus value is represented by individual neurons in OFC and amygdala, and will provide information about the relative timing of these "value signals" that may clarify how these two areas interact. The more complex task will reveal whether these signals can change flexibly enough to reflect the value of a stimulus when it can change rapidly depending on context. It may also reveal whether and how contextual information - i.e., the "rule" for interpreting the value of a stimulus - is encoded in OFC and/or amygdala. Together, these experiments may elucidate how value assignments are formed and then modulated by a neural circuit involving limbic areas (such as the amygdala) and areas that may be involved in the executive control of emotional responses (such as OFC). Learning how this circuit functions normally is an important first step in understanding how it may dysfunction in psychiatric disorders like PTSD, clinical depression, and schizophrenia. Relevance: In order to make everyday decisions, people (and animals) need to be able to assign values (such as "good" or "bad") to objects in the environment, and sometimes to change these values depending on the context in which an object occurs. This process is disrupted in many psychiatric disorders, such as depression and post-traumatic stress disorder. The focus of this proposal is on understanding how emotional and cognitive brain areas interact to learn and modify the values of objects - knowledge that may aid our understanding, and eventually treatment, of the causes of psychiatric disorders.

描述（由申请人提供）：为了指导动机行为，人类和动物需要能够灵活评估环境中刺激的情感值（正面或负面）。这个过程在精神疾病中可能会出错。例如，在创伤后应激障碍（PTSD）中，与创伤相关的某些刺激可能会被赋予过于消极、不灵活的值，即使它们应该是非威胁性的。该提案的重点是刺激值如何在大脑中表示，以及这种表示如何随着环境背景的变化而变化。为了研究这一点，我们将同时记录两个大脑区域——杏仁核和眶额皮层（OFC）的神经活动，同时猴子执行两项任务之一：一项简单的条件反射任务，其中视觉刺激与奖励或惩罚相关联；以及一项上下文相关任务，其中视觉刺激的含义根据上下文线索随时变化。更简单的任务将揭示刺激值是否以及如何由 OFC 和杏仁核中的单个神经元表示，并将提供有关这些“值信号”的相对时间的信息，这可能会阐明这两个区域如何相互作用。更复杂的任务将揭示当刺激可以根据上下文快速变化时，这些信号是否可以足够灵活地变化以反映刺激的价值。它还可以揭示上下文信息（即解释刺激值的“规则”）是否以及如何在 OFC 和/或杏仁核中编码。总之，这些实验可以阐明价值分配是如何形成的，然后如何通过涉及边缘区域（例如杏仁核）和可能涉及情绪反应执行控制的区域（例如 OFC）的神经回路进行调节。了解这个回路如何正常运作是了解它如何在创伤后应激障碍、临床抑郁症和精神分裂症等精神疾病中发挥功能障碍的重要第一步。相关性：为了做出日常决策，人们（和动物）需要能够为环境中的对象分配值（例如“好”或“坏”），有时还需要根据对象出现的上下文来更改这些值。这一过程在许多精神疾病中被破坏，例如抑郁症和创伤后应激障碍。该提案的重点是了解情绪和认知大脑区域如何相互作用以学习和修改物体的价值 - 这些知识可能有助于我们理解并最终治疗精神疾病的原因。