Neural basis of reward-based choice

 描述（由申请人提供）：当我们在两个选项之间选择基于他们承诺的奖励时，我们利用了一套高度专业化的大脑回路。了解这个回路很重要，因为它是滥用药物的主要目标，因为基于奖励的决定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。我们关注的是一个大脑区域，即腹内侧前额叶皮层，神经成像研究一直认为它是奖励和决策的关键部位，但它的功能仍然是个谜。为了探索它的功能，我们将记录单个神经元在这个领域的反应，而受试者执行两个不同的任务，专门设计来探测选择过程。首先，我们将研究风险选项的表示，看看vmPFC神经元是否单独或在一个统一的框架中表示它们的组成部分-风险，赌注，概率。其次，我们将观察这个区域的神经元是否在一个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关于奖励的信息是如何由vmPFC神经元表示的。然后，我们将在一个简单的决策任务中检查这些神经元的反应，在这个任务中，受试者可以接受或拒绝带来成本和收益的提议。最后，我们将测试是否vmPFC在选择中发挥了因果作用，通过人为改变神经元的活动与刺激电极。后 完成这些研究，我们将有史以来第一次基本了解奖励为基础的选择过程的神经机制。

 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.