Role of basal ganglia in reward-biased visual decisions

描述（由申请人提供）：日常行为通常由外部视觉线索与内部欲望，厌恶和特质偏见之间的复杂相互作用驱动。例如，接住一个棒球需要跟随它的飞行轨迹，但也要抑制它的运动。 在餐馆点餐取决于个人对食物的偏好，但也可能受到附近其他食物的视觉（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感知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神经节在协调视觉和非感觉因素以指导视觉行为中所起的中心作用，基底神经节是一个涉及学习、评价和动作选择的皮质下脑区的互连网络。我们的四个具体目标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。目标1建立了一个实验和理论框架，定量测量决策行为的基础上不确定的感官信息和奖励诱导的内部偏好。目标2使用单神经元记录来识别尾状核中的神经计算，尾状核是基底神经节眼神经通路中的灵长类动物输入结构，在动物中执行目标1中开发的新任务。 目标3使用电微刺激施加在尾状核的网站在不同的时间在动物试验执行任务，以测试在决策过程中的因果关系的作用。目的4使用反和顺向刺激技术来检查从前额皮质发送到尾状核的信号的性质，并确定决策和奖励相关处理在尾状核中出现或直接发送的程度。拟议的项目代表了尾状核的复杂决策涉及不确定的视觉刺激和不同的奖励期望的作用的第一次系统的检查。完成后，新的结果将大大推进我们对复杂视觉决策的神经基础的理解，通过提供急需的见解，了解大脑中视觉线索如何以及在何处与非感官因素相结合，以指导我们的决策。从长远来看，这些见解将有助于更全面地了解目标导向行为的临床障碍，特别是涉及基底神经节的障碍。

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.