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，通过将目光指向（“注视”）兴趣点来主动获取信息。人类和其他灵长类动物通常会以3-5 Hz的频率，通过快速的“扫视”眼球运动来扫描大量的短暂注视。在每次注视时，视网膜输出的齐射进入系统，并产生由刺激质量与每个大脑区域内神经元特性的相互作用确定的大脑激活的时空模式。尽管有这些众所周知的动态，在眼动的背景下分析视觉活动的困难导致了传统的方法，即检查对眼睛保持稳定的刺激的反应，无论是在麻醉的非人类受试者中的全身麻痹，还是在研究清醒的受试者（猴子或人类）时，都需要在刺激呈现期间稳定地注视。我们和其他人通过跟踪眼睛，并通过使用扫视或注视的开始作为事件触发器进行响应平均和/或单一试验分析，研究了猴子的主动视觉。这些研究清楚地表明，这种主动视觉利用了由眼神经系统产生的非视网膜“传出复制”信号，其重置了整个视觉通路中正在进行的兴奋性波动（振荡）的相位。由于这种相位重置将周围神经元振荡的高兴奋性相位与视觉信息的流入对齐，我们假设：1）相同的重置信号增强了不同大脑区域中神经元集合之间的振荡相位相干性，并且这种相干性增强了通过系统的信息流，并增强了大脑对眼球运动所针对的对象的表示，以及2）扫视注视周期为信息编码和变换提供了明确的上下文，由基本采样率组织（即，眼睛运动的速率），以及合并/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。我们的主要目标是开发一种可行的方法来高分辨率地研究人类的主动视觉动态。 我们有两个具体的目标：1 -定义的影响，主动扫视采样的动态视觉处理。2.研究自然场景主动采样过程中的信息编码和转换。 主动视觉动态的有效分辨率是至关重要的，因为除了一些其他形式，如追踪眼球运动，简短的，快照般的固定提供了主要的手段采样的视觉环境。在这些方面对视觉的更好理解将对改善视觉功能障碍的机械理解以及认知缺陷具有许多意义，这些认知缺陷源于广泛的疾病中的异常视觉搜索行为，包括亨廷顿氏病、帕金森氏病、多动症、胎儿酒精综合征、精神分裂症。