Neural basis of reward-based choice

 描述(由申请者提供)：当我们根据他们承诺的回报在两个选项中进行选择时，我们利用了一套高度专业化的大脑回路。了解这一回路很重要，因为它是滥用药物的主要目标，而且基于奖励的决定调节失调是药物成瘾的主要症状。这个项目的目标是了解电路是如何工作的。我们专注于大脑的一个区域，即腹内侧前额叶皮质，神经成像研究一直认为该区域是奖励和决策的关键部位，但其功能仍然神秘。为了探索其功能，我们将记录该区域单个神经元的反应，同时受试者执行两种专门为探索选择过程而设计的不同任务。首先，我们将研究风险期权的表示，并看看vmPFC神经元是单独表示它们的组成部分-风险、风险、概率，还是在一个统一的框架中。其次，我们将观察这一区域的神经元是否在共同的尺度上发出积极和消极的信号。前两个项目将告诉我们vmPFC神经元是如何代表有关奖励的信息的。然后，我们将在一项简单的决策任务中检查这些神经元的反应，在这项任务中，受试者可以接受或拒绝带来成本和收益的提议。最后，我们将测试vmPFC是否通过使用刺激电极人工改变那里的神经元活动在选择中起到致因作用。之后 完成这些研究后，我们将首次对基于奖励的选择过程的神经机制有一个基本的了解。

 DESCRIPTION (provided by applicant): When we choose between two options based on the rewards they promise, we make use of a highly specialized set of brain circuitry. Understanding this circuitry is important because it is the major target of abused drugs and because dysregulation of reward-based decisions is a major symptom of drug addiction. The goal of this project is to understand how that circuitry works. We focus on one brain area, the ventromedial prefrontal cortex, that is consistently identified by neuroimaging studies as a critical site for rewards and decisions, but whose function remains mysterious. To probe its function, we will record responses of single neurons in this area while subjects perform two different tasks specifically designed to probe choice processes. First, we will examine the representation of risky options, and see whether vmPFC neurons represent their components - risk, stakes, probability, separately, or in a unified framework. Second, we will see whether neurons in this area signal positive and negative offers on a common scale. These first two projects will tell us how information about rewards is represented by vmPFC neurons. Then we will examine the responses of these neurons in a simple decision-making task in which subjects can accept or reject offers that bring costs and benefits. Finally, we will test whether vmPFC plays a causative role in choice by artificially altering neuronal activity there with a stimulating electrode. After completing these studies, we will have a first-ever basic understanding of the neuronal mechanics of reward-based choice processes.