CRCNS:Investigating perceptual processing speed and its impact on choice behavior

CRCNS：调查感知处理速度及其对选择行为的影响

• 批准号: 8289583
• 负责人: Emilio Salinas
• 金额: $ 30.11万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-30 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8289583
• 关键词: Acceleration; Affect; Attention; Behavior; Brain; Choice Behavior; Cognitive; Color; Commit; Computer Simulation; Decision Making; Dependency; Diagnostic; Education; Educational process of instructing; Equipment; Future; Judgment; Knowledge; Laboratories; Life; Light; Measurement; Measures; Mental disorders; Minor; Modeling; Monkeys; Motivation; Motor; Neurobiology; Neurons; Neurosciences; Performance; Postdoctoral Fellow; Preparation; Principal Investigator; Process; Psychophysiology; Reaction Time; Readiness; Reporting; Research; Research Infrastructure; Resolution; Rewards; Role; Sensory; Signal Transduction; Societies; Speed; Stimulus; Task Performances; Testing; Time; Training; Variant; base; decision-making capacity; design; frontal eye fields; graduate student; human subject; microstimulation; neural circuit; neuromechanism; neurophysiology; novel; oculomotor; processing speed; programs; relating to nervous system; research study; response; skills; tool; trafficking; undergraduate student

DESCRIPTION (provided by applicant): The neurobiology of choice behavior has been intensely studied with laboratory tasks in which a subject makes a perceptual judgement and indicates the result with a motor action. Combined psychophysical and neurophysiological experiments have thus characterized perceptual decision-making capacity as a function of signal quality, strength, and subjective value, and have revealed many of the underlying neural circuits and their specific roles. However, the fundamental question of timing has been much harder to tackle: how long does it take to make a perceptual judgment, versus executing a motor action to report that judgment? At what point in time is a subject committed to a particular choice, and what neural mechanisms determine that? These issues are relevant to many real-life situations that require quick choices; for instance, when a driver sees a traffic light and must rapidly decide whether to step on the brake or the accelerator, depending on the light's color. But making accurate timing measurements is complicated because they are affected by numerous sensory and motor factors, such as readiness, motivation, task difficulty and speed-accuracy trade-offs. Consequently, current knowledge about the temporal dynamics of perceptual decision-making is rather crude. The PIs in this project recently developed a task that eliminates these confounds and produces a new psychophysical measure, the tachometric curve, which isolates a subject's perceptual processing capacity and quantifies it with unprecedented temporal resolution. They have also constructed a computational model that reproduces the subjects' behavior with great detail. The new paradigm and the model will be used jointly to investigate the timing of perceptual judgments and its neural basis. Specific model predictions will be tested via single-neuron recording and microstimulation within the Frontal Eye Field (FEF) of monkeys trained to perform the task under a variety of conditions. There are three specific aims. Aim 1: To test the hypothesis that changes in perceptual processing speed are manifested as changes in the slope of the tachometric curve (psychophysically) and in the acceleration of the oculomotor activity associated with a saccadic choice (neurally). According to the model, the tachometric curve and the oculomotor activity associated with saccadic choices should depend in specific ways on perceptual difficulty. To measure this dependency, subjects will perform 3 versions of the same choice task that will vary in perceptual difficulty according to different stimulus features to be discriminated. Aim 2: To test the hypothesis that when perceptual processing speed remains constant, both the slope of the tachometric curve and the acceleration of the oculomotor activity will stay constant as well, even if other measures of psychophysical performance do change. These experiments are thus complementary to those of Aim 1. Subjects will perform 4 variants of the choice task in which perceptual difficulty will be fixed but the likelihoods and rewards associated with the two possible motor responses will vary. The subject's performance level, reaction times and proportions of choices are expected to change drastically across the 4 conditions, but the measured correlates of perceptual processing speed should not. Aim 3: To test the hypothesis that an overall increase in the level of activation in FEF alters the timing and accuracy of a subject's choices, but not the observed perceptual processing speed. Subthreshold microstimulation current will be injected into the FEF at different points in time during task performance. The question is whether the evoked activity is interpreted as a purely motor signal or if it has a direct impact on the subject's perceptual processing capacity. Intellectual merit: The proposed experiments track how a subject's perceptual performance unfolds in time, and open up an entirely new avenue for investigating how choices are made. It will be possible (1) to determine the specific contributions of various cognitive factors such as attention, motivation, motor preparation, and perceptual processing speed to a subject's measured psychophysical performance, (2) to investigate how neuronal activity is related to each of these factors during a choice task, and (3) to reveal how the time course of this neuronal activity correlates with the time course of a subject's choice accuracy. Broader impacts: (1) Teaching. The results of this study will be incorporated into courses taught by the PIs. (2) Education. Undergraduate students with a minor in neuroscience will be hosted for research academic credit in the PIs' laboratories. A graduate student and a postdoctoral fellow will develop combined electrophysiological and computational skills. (3) Scientific understanding. The results are expected to be widely discussed and disseminated. (4) Enhancement of infrastructure for research. Cutting-edge equipment will be acquired for use in this and future projects. (5) Benefits to society. The novel task design has the potential to be adapted to human subjects and become a powerful diagnostic tool for elucidating how specific neural circuits or brain 'modules' are compromised by a given mental disorder.

描述（由申请人提供）：选择行为的神经生物学已通过实验室任务进行了深入的研究，其中受试者做出感知判断，并通过运动动作表明结果。因此，心理物理和神经生理实验的组合已经表征了感知决策能力是信号质量，强度和主观价值的函数，并揭示了许多基本的神经回路及其特定作用。但是，时间安排的基本问题很难解决：做出感知判断需要多长时间，而不是执行运动行动来报告该判断？在什么时间点，一个主题是一个特定选择的主题，哪些神经机制决定了这一点？这些问题与许多需要快速选择的现实情况有关。例如，当驾驶员看到交通信号灯并必须迅速决定是否踩下制动器还是加速器，具体取决于灯的颜色。但是，进行准确的时序测量很复杂，因为它们受到许多感觉和运动因素的影响，例如准备，动机，任务难度和速度准确性的权衡。因此，关于感知决策的时间动态的当前知识相当粗糙。该项目中的PI最近制定了一项任务，可以消除这些混杂并产生一种新的心理物理测量，即转速曲线，该测量曲线隔离了受试者的感知处理能力，并以前所未有的时间分辨率量化了它。他们还构建了一个计算模型，该模型详细介绍了受试者的行为。新的范式和模型将共同研究感知判断及其神经基础的时间。特定的模型预测将通过单神经元记录和经过多种条件下执行任务的猴子额眼野外（FEF）的微刺激进行测试。有三个特定的目标。目的1：检验以下假设：感知处理速度的变化表现为转速曲线的斜率（心理学上）的变化以及与SACCADIC选择（神经性）相关的动眼活动的加速度。根据该模型，与Saccadic选择相关的转速曲线和动眼活动应以特定方式取决于感知难度。为了衡量这种依赖性，受试者将执行3个版本的同一选择任务，这些任务会根据不同的刺激特征而在感知难度上有所不同。目的2：测试以下假设：当感知处理速度保持恒定时，即使心理物理性能的其他度量也会改变，转速曲线的斜率和动力学活性的加速度也将保持恒定。因此，这些实验与AIM 1的实验相辅相成。受试者将执行4种选择任务的变体，在这些任务中，感知难度将被固定，但与两个可能的电机响应相关的可能性和奖励会有所不同。受试者的绩效水平，反应时间和选择比例将在4个条件下发生巨大变化，但是所测得的感知处理速度的相关性不应。目标3：检验以下假设：FEF中激活水平的总体增加会改变受试者选择的时机和准确性，但不能改变观察到的感知处理速度。在任务执行过程中，下阈值微刺激电流将在不同时间点注入FEF。问题是，诱发活动是否被解释为纯粹的电机信号，还是对受试者的感知处理能力有直接影响。智力优点：拟议的实验跟踪受试者的感知表现如何及时展开，并为研究选择的方式开辟了全新的途径。 （1）可以确定各种认知因素的特定贡献，例如注意力，动机，运动制备和感知处理速度与受试者测量的心理物理性能，（2）研究神经元活动在选择任务期间与这些因素的相关性如何相关，并且（3）揭示了这种神经元活动时间与该学位的过程如何相关。更广泛的影响：（1）教学。这项研究的结果将纳入PIS教授的课程中。 （2）教育。具有神经科学未成年人的本科生将在PIS的实验室中主持研究学分。研究生和博士后研究员将发展结合电生理和计算能力。 （3）科学理解。预计结果将被广泛讨论和传播。 （4）增强研究基础设施。最先进的设备将用于该项目和将来的项目。 （5）对社会的好处。新颖的任务设计有可能适应人类受试者，并成为阐明特定的神经回路或大脑“模块”如何因给定精神障碍而损害特定的神经回路或大脑的强大诊断工具。