Neurophysiology of active vision in humans

人类主动视觉的神经生理学

• 批准号: 9145712
• 负责人: CHARLES E SCHROEDER
• 金额: $ 20万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-30 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9145712
• 关键词: Appetitive Behavior; Area; Attention deficit hyperactivity disorder; Autistic Disorder; Brain; Brain region; Clinical; Code; Cognitive deficits; Disease; Electrooculogram; Environment; Epilepsy; Equilibrium; Event; Eye; Eye Movements; Feedback; Fetal Alcohol Syndrome; Functional Magnetic Resonance Imaging; Functional disorder; Goals; Health; Human; Huntington Disease; Implant; Implanted Electrodes; Life; Mental disorders; Monkeys; Nature; Neurobiology; Neurons; Ocular Fixation; Operative Surgical Procedures; Output; Paralysed; Parkinson Disease; Patients; Pattern; Phase; Primates; Process; Property; Research; Resolution; Retinal; Risk; Saccades; Sampling; Scalp structure; Scanning; Scheme; Schizophrenia; Side; Signal Transduction; Staging; Stimulus; Syndrome; System; Testing; Vision; Visual; Visual Cortex; Visual Pathways; Work; active vision; awake; experience; extrastriate visual cortex; gaze; high risk; improved; information processing; interest; neurophysiology; neuropsychiatric disorder; oculomotor; response; sample fixation; spatiotemporal; stem; theories; visual information; visual process; visual processing; visual search; voltage

 DESCRIPTION (provided by applicant): In natural vision, information is acquired actively, by directing gaze toward ("fixating on") points of interest. Humans and other primates typically scan a visual scene with a large number of brief fixations, at a rate of 3-5 Hz, separated by rapid ``saccadic'' eye movements. At each fixation, a volley of retinal outputs courses into the system and produces a spatiotemporal pattern of brain activation determined by the interaction of stimulus qualities with properties of neurons within each brain area. Despite these well known dynamics, the difficulties in analyzing visual activity in the context of eye movements has led to the traditional approach of examining responses to stimuli that are presented with the eye held stable, either by systemic paralysis in anesthetized nonhuman subjects, or when studying awake subjects (monkeys or humans), by requirements to fixate steadily during stimulus presentation. We and others have investigated active vision in monkeys by tracking the eyes, and by using the onset of the saccade or the fixation as event triggers for response averaging and/or single trial analysis. These studies clearly show that such active vision exploits non-retinal "efference copy" signals generated by the oculomotor system, which reset the phase of ongoing excitability fluctuations (oscillations) throughout the visual pathways. Because this phase reset aligns the high excitability phase of ambient neuronal oscillations with the inflow in visual information, we hypothesize that 1) the same reset signal enhances oscillatory phase coherence between neuronal ensembles in different brain regions and that this coherence enhances information flow through the system and augments the brain's representation of objects targeted by eye movements, and 2) the saccade-fixation cycle provides an explicit context for information encoding and transformation, organized by a basic sampling rate (i.e., the rate of eye movements), and incorporating/ organizing both bottom-up hierarchical information processing and top-down "when/what/where" predictions. Our broad goal is to develop a workable approach to high-resolution study of Active Vision dynamics in humans. We have two specific aims: 1 - Define the impact of Active Saccadic Sampling on the dynamics of visual processing. 2 - Investigate information encoding and transformation during Active Sampling of naturalistic scenes. Effective resolution of the dynamics of active vision is of fundamental importance because, aside from a few other forms, such as pursuit eye movements, the brief, snapshot-like fixation provides the major means of sampling the visual environment. An improved understanding of vision in these terms will have numerous implications for improved mechanistic understanding of visual dysfunction, as well as cognitive deficits that stem from abnormal visual search behavior in a wide range of disorders including Huntington's, Parkinson's, ADHD, Fetal Alcohol Syndrome, Schizophrenia.

 描述（由申请人提供）：在自然视觉中，通过将目光转向（“注视”）感兴趣的点来主动获取信息。人类和其他灵长类动物通常以一定的速度以大量短暂的注视来扫描视觉场景。 3-5 Hz，由快速的“扫视”眼球运动分隔。每次注视时，一系列视网膜输出都会进入系统，并产生由相互作用决定的大脑激活的时空模式。尽管有这些众所周知的动态，但在眼球运动背景下进行视觉分析活动的困难导致了检查对眼睛保持稳定时呈现的刺激的反应的传统方法。通过麻醉的非人类受试者的系统性麻痹，或者当研究稳定清醒的受试者（猴子或人类）时，通过在刺激呈现期间注视的要求，我们和其他人通过跟踪眼睛并利用眼跳的开始来研究猴子的主动视觉。或固定为用于反应平均和/或单次试验分析的事件触发器这些研究清楚地表明，这种主动视觉利用了动眼系统产生的非视网膜“输出复制”信号，该信号重置了整个视觉通路中持续兴奋性波动（振荡）的阶段。由于此相位重置将环境神经振荡的高兴奋性阶段与视觉信息的流入对齐，因此我们认为 1) 相同的重置信号增强了之间的振荡相位一致性。不同大脑区域的神经集合，这种一致性增强了系统中的信息流，并增强了大脑对眼球运动目标物体的表征，2）扫视固定周期为信息编码和转换提供了明确的背景，由基本的采样率（即眼球运动的速率），并合并/组织自下而上的分层信息处理和自上而下的“何时/什么/何处”预测。我们的总体目标是开发一种可行的高分辨率方法。我们有两个具体目标： 1 - 定义主动扫视采样对视觉处理动态的影响 2 - 研究自然场景动态采样过程中的信息编码和转换。主动视觉至关重要，因为除了一些其他形式（例如眼球追踪运动）之外，短暂的、快照式的注视提供了对视觉环境进行采样的主要手段。在这些方面加深对视觉的理解将产生许多影响。为了改进对视觉功能障碍以及由亨廷顿舞蹈症、帕金森舞蹈症、多动症、胎儿酒精综合症、精神分裂症等多种疾病中的异常视觉搜索行为引起的认知缺陷的机制理解。