Role of basal ganglia in reward-biased visual decisions

描述(由申请人提供)：日常行为通常是由外部视觉提示和内部欲望、厌恶和特殊偏见之间的复杂相互作用驱动的。例如，接住棒球需要遵循它在飞行中的轨迹，但也需要抑制 害怕被它撞到。在餐馆点餐取决于个人的食物偏好，但也可能受到附近供应的其他食物的视觉(和气味)的影响。尽管我们最近在理解大脑如何解释视觉输入以形成知觉决策，以及大脑如何使用结果预期来形成基于价值的决策方面取得了进展，但我们仍然不清楚大脑如何协调这些过程。我们的目标是建立和描述基底节在协调视觉和非感觉因素以指导眼动行为方面所起的核心作用。基底节是皮质下脑区的一个相互连接的网络，涉及学习、评估和动作选择。我们的四个具体目标是通过将行为的定量测量与电生理技术相结合来解决这个问题。目的1基于不确定的感觉信息和奖赏诱导的内部偏好，建立一个定量测量决策行为的实验和理论框架。目标2使用单神经元记录来识别执行目标1中开发的新任务的动物的尾状核--基底节动眼神经通路中的一种灵长类输入结构--的神经计算。目标3在执行任务的动物的试验中，在不同时间对尾状体内的部位施加微刺激，以测试在决策过程中的因果作用。目的4使用反向和顺向刺激技术来检测从前额叶皮质发送到尾状核的信号的性质，并确定决策和奖励相关的加工在尾状核中出现的程度或被直接发送到那里的程度。这个拟议的项目代表了第一次系统地研究尾状核在复杂决策中的作用，涉及到不确定的视觉刺激和不同的奖励预期。完成后，新的结果将极大地促进我们对复杂视觉决策的神经基础的理解，通过提供急需的洞察力，了解大脑中视觉提示如何以及在哪里与非感官因素相结合来指导我们的决策。从长远来看，这些见解将有助于建立对目标导向行为的临床损害的更完整的理解，特别是那些涉及基底节的损害。

DESCRIPTION (provided by applicant): Everyday behaviors are often driven by a complex interplay between external visual cues and internal desires, aversions, and idiosyncratic biases. For example, catching a baseball requires following its trajectory in flight but also suppressing a fear of getting hit by it. Ordering a meal at a restaurant depends on personal food preference but can also be biased by the sights (and smells) of other meals being served nearby. Despite recent progress in our understanding of how the brain interprets visual inputs to form perceptual decisions and how the brain uses outcome expectations to form value-based decisions, it remains unclear how the brain coordinates these processes. Our goal is to establish and characterize the central role played by the basal ganglia, an interconnected network of subcortical brain regions implicated in learning, valuation, and action selection, in coordinating visual and non-sensory factors to guide oculomotor behavior. Our four specific Aims address this topic by combining quantitative measures of behavior with electrophysiological techniques. Aim 1 establishes an experimental and theoretical framework to quantitatively measure decision behavior based on both uncertain sensory information and reward-induced internal preferences. Aim 2 uses single-neuron recordings to identify the neural computations in caudate, a primate input structure in the basal ganglia oculomotor pathway, in animals performing the novel task developed in Aim 1. Aim 3 uses electrical microstimulation applied to sites in the caudate at different times within a trial of animals performing the task to test for a causal role in the decision process. Aim 4 uses anti- and orthodromic stimulation techniques to examine the nature of the signals sent from prefrontal cortex to caudate and to determine the extent to which decision- and reward-related processing emerges in caudate or is sent there directly. The proposed project represents the first systematic examination of the caudate's role in complex decision-making involving uncertain visual stimuli and varying reward expectations. Upon completion, the new results will substantially advance our understanding of neural basis of complex visual decision-making, by providing much-needed insights into how and where in the brain visual cues are combined with non-sensory factors to guide our decisions. In the long-term, these insights will help build a more complete understanding of clinical impairments in goal-directed behavior, especially those involving the basal ganglia.