Project 1: Cortical Dynamics of Top-Down Control in Visual Active Sensing

项目1：视觉主动感知中自上而下控制的皮层动力学

• 批准号: 10175034
• 负责人: Josef Parvizi
• 金额: $ 25.34万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-15 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10175034
• 关键词: Alpha Rhythm; Anatomy; Attention; Auditory; Behavior; Behavioral; Brain; Code; Cues; Data; Discrimination; Electrocorticogram; Electrodes; Environment; Epilepsy; Exploratory Behavior; Eye Movements; Frequencies; Functional Magnetic Resonance Imaging; Goals; Human; Link; Location; Macaca; Measures; Memory; Modeling; Monkeys; Neurobiology; Neurons; Neurosciences; Operative Surgical Procedures; Parietal Lobe; Patients; Perception; Performance; Periodicity; Peripheral; Phase; Process; Psychophysics; Rest; Role; Saccades; Sampling; Sensory; Signal Transduction; Stimulus; Structure; Study models; Surface; System; Testing; Thalamic structure; Time; Uncertainty; Visual; Visual Cortex; Visual Perception; Visual attention; Visuospatial; Work; auditory processing; base; directed attention; experimental study; instrument; network models; neural correlate; neuroimaging; neuromechanism; predictive modeling; relating to nervous system; response; sample fixation; theories

Visual perception is limited by two fundamental rhythms, a 7-10 Hz theta/alpha rhythm that describes fluctuations in psychophysical performance and a 3-5 Hz rhythm related to saccadic eye movements. The structure of a task may impose or entrain an additional rhythm, such as when a target stimulus follows a cue at a fixed interval. The goal of this project is to identify in humans the neural correlates of these rhythms and determine their relationship to intrinsic rhythms of spontaneous activity. Neural activity is measured using electrocorticography (ECoG) in patients undergoing surgery for epilepsy. In Expt. 1, localizers are conducted to identify electrodes that respond to saccadic eye movements, foveal stimuli, and/or show spatially selective responses to peripheral stimuli. Functional magnetic resonance imaging is used to identify the large-scale brain network associated with each electrode. In Expt. 2 subjects are cued to detect a target under conditions of temporal uncertainty. In the one-location condition, the target only appears at the cued location. In the two- location condition, the target appears equi-probably at one of two locations. Consistent with previous studies indicating a fixed sampling rhythm, performance should fluctuate in the 1-location condition at twice the frequency as the fluctuations in each location of the 2-location condition. We then identify the neural correlate(s) of this rhythm in electrodes identified by the localizer. These correlates may be associated with local field potentials, modulations of band-limited power, or phase-amplitude relationships that couple low frequencies to high frequencies. In addition, we determine whether these correlates can be identified in intrinsic activity measured at rest. Expt. 3 compares the 1-location and 2-location conditions when the interval between the cue and target is fixed, corresponding to a task-imposed rhythm and temporal certainty. The question is whether the neural correlates of the task-imposed rhythm are independent of the intrinsic rhythms measured in Expt. 2. Finally, Expt. 4 compares the neural rhythms that are generated when subjects process foveal stimuli during a sequence of saccades as compared to the same foveal stimuli when fixation is maintained. We test the hypothesis that saccades produce a phase reset that aligns the maximal excitability phase of internal rhythms with incoming sensory signals. This hypothesis predicts that high gamma sensory evoked responses and behavioral performance should be facilitated by saccades. We also determine the relationship between the neural correlates of the saccadic rhythm, the 7-10 Hz sampling rhythm, and spontaneous rhythms measured at rest. We will interact closely with Project 2, which uses 2 of these tasks in monkey intracortical recordings, and with Projects 3 and 4 that study parallel auditory tasks in humans and monkeys, respectively. Along with Project 3, we will supply data to dynamical network modeling studies (Project 5), and use their findings to refine and/or modify our paradigms as work progresses. Integration of findings across these studies will build more robust models of brain mechanisms operating in Active Sensing.

视觉感知受到两种基本节奏的限制，即描述 7-10 Hz theta/alpha 节奏 心理物理表现的波动以及与眼球扫视运动相关的 3-5 Hz 节律。这 任务的结构可能会强加或引入额外的节奏，例如当目标刺激遵循以下提示时 固定间隔。该项目的目标是在人类中识别这些节律和的神经关联 确定它们与自发活动的内在节律的关系。神经活动的测量使用 接受癫痫手术的患者的皮质电图（ECoG）。在Expt。 1、定位器进行 识别对眼球扫视运动、中心凹刺激做出反应和/或显示空间选择性的电极 对周围刺激的反应。功能磁共振成像用于识别大范围 与每个电极相关的大脑网络。在Expt。 2 名受试者被提示在特定条件下检测目标 时间的不确定性。在单位置条件下，目标仅出现在提示位置。在两个- 位置条件下，目标等概率出现在两个位置之一。与之前的研究一致 表示固定采样节奏，在 1 位置条件下，性能应以两倍的速度波动 频率作为 2 位置条件的每个位置的波动。然后我们识别神经 将此节律与定位器识别的电极相关联。这些相关性可能与 局部场电位、带限功率调制或低耦合的相位幅度关系 频率到高频。此外，我们确定这些相关性是否可以在 休息时测量的内在活动。出口。 3 比较 1 位置和 2 位置条件时的间隔 提示和目标之间是固定的，对应于任务强加的节奏和时间确定性。这 问题是任务强加节奏的神经相关性是否独立于内在节奏 在Expt中测量。 2. 最后，专家。图 4 比较了受试者处理信息时产生的神经节律 一系列眼跳期间的中央凹刺激与注视时相同的中央凹刺激相比 维持。我们测试了这样的假设：眼跳会产生与最大兴奋性对齐的相位重置 内部节律的阶段与传入的感觉信号。该假设预测高伽马感觉 眼跳应该促进诱发反应和行为表现。我们还确定 扫视节律、7-10 Hz 采样节律的神经相关性之间的关系 休息时测量的自发节律。我们将与项目 2 密切互动，该项目使用其中 2 个任务 猴子皮质内录音，以及研究人类和人类并行听觉任务的项目 3 和 4 分别是猴子。与项目 3 一起，我们将为动态网络建模研究提供数据 （项目 5），并随着工作的进展使用他们的发现来完善和/或修改我们的范例。整合 这些研究的结果将建立更强大的主动感知大脑机制模型。