权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Visual Crowding

视觉拥挤

基本信息

批准号：
10357945
负责人：
ADAM KOHN
金额：
$ 39.21万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-02-01 至 2024-01-31
项目状态：
已结题

项目摘要

Summary Crowding is a perceptual phenomenon in which a clearly discernible stimulus becomes unrecognizable because of nearby `distractor' stimuli. Crowding affects core aspects of visual processing, including feature integration, scene perception and reading. Because crowding is stronger in non-foveal vision, it strongly affects individuals with central vision loss (e.g. macular degeneration), with substantial consequences for their quality of life. Crowding has been explored extensively in human psychophysical studies. Functional imaging and electrophysiological studies in humans have provided some neural correlates of crowding in early and midlevel visual cortex, but the neural underpinnings of crowding remain largely unexplored and poorly understood. This project will determine how crowded displays affect the representation of sensory information by neuronal populations in low and midlevel cortex (encoding), how crowding affects the manner in which this sensory information is used to make perceptual judgments (decoding), and whether the effects of crowding can be mitigated by brief periods of sensory experience. In Specific Aim 1, we will record from neuronal populations in primary visual cortex (V1) and V4 of macaque monkeys. We will test the hypothesis that crowding corrupts sensory representations in these areas. We will determine how crowded displays affect neuronal responsivity, tuning, and variability, and interneuronal noise correlations. Making use of recent advances in understanding population codes, we will assess how chances in these response features combine to affect encoding of visual information with crowding. In Specific Aim 2, we will train animals to perform a fine orientation discrimination task, for target stimuli presented in isolation and with distractors. We will use a stimulus paradigm that allows us to compute “psychophysical kernels”—a method for assessing perceptual strategy by which different elements of a visual display are combined to make decisions. We will pair these behavioral measures with recordings of neuronal population in V1 and V4, to infer the read-out strategy used by the animal to relate sensory responses to perceptual decisions. These experiments will test the hypothesis that crowding arises in part from suboptimal read out of sensory information. In Specific Aim 3, we will test whether brief periods of visual adaptation can mitigate crowding. We hypothesize that adaptation can be used to improve the salience of novel stimuli, with heightened salience resulting in improved perceptual performance. We will test our hypothesis by measuring the population information for target stimuli in isolation or with distractors, under control conditions and different adaptation states. We will also test whether adaptation alters the read-out strategy used by animals in our orientation discrimination task. These experiments will reveal which aspects of crowding are most plastic, and test for a novel functional benefit of sensory adaptation. Together our aims will provide a comprehensive investigation of the neural basis of crowding, providing knowledge needed to develop therapeutic and behavioral strategies to alleviate the quality of life issues caused by crowding.

概括拥挤是一种感知现象，其中清晰可辨的刺激变得无法识别因为附近的“干扰”刺激。拥挤影响视觉处理的核心方面，包括特征整合、场景感知和阅读。由于非中心凹视力的拥挤程度更强，因此会强烈影响中央视力丧失（例如黄斑变性）的个体，对其质量产生重大影响的生活。拥挤现象在人类心理物理学研究中得到了广泛的探讨。功能成像和人类电生理学研究提供了早期和中期拥挤的一些神经相关性视觉皮层，但拥挤的神经基础在很大程度上仍未被探索和了解。这该项目将确定拥挤的显示器如何影响神经元对感觉信息的表示低层和中层皮层的人口（编码），拥挤如何影响这种感觉的方式利用信息进行感性判断（解码），拥挤的影响是否可以被短暂的感官体验可以缓解这种情况。在具体目标 1 中，我们将记录猕猴的初级视觉皮层（V1）和 V4。我们将检验拥挤腐败的假设这些领域的感官表征。我们将确定拥挤的显示器如何影响神经元反应性，调谐、变异性以及神经元间噪声相关性。利用最新的理解进展人口代码，我们将评估这些响应特征的机会如何结合起来影响视觉编码信息拥挤。在具体目标2中，我们将训练动物进行精细的方向辨别任务，针对孤立且带有干扰因素的目标刺激。我们将使用一种刺激范式，允许我们计算“心理物理内核”——一种评估感知策略的方法，通过该方法不同的视觉显示的元素被组合起来做出决策。我们将把这些行为测量与 V1 和 V4 中神经元群的记录，以推断动物用于关联的读出策略对知觉决策的感官反应。这些实验将检验以下假设：拥挤发生在部分来自次优读出的感官信息。在具体目标 3 中，我们将测试短暂的时间是否视觉适应可以缓解拥挤。我们假设适应可以用来提高显着性新颖的刺激，其显着性提高，从而提高感知表现。我们将测试我们的通过测量孤立或干扰条件下目标刺激的总体信息来提出假设控制条件和不同的适应状态。我们还将测试适应是否会改变读数动物在我们的方向辨别任务中使用的策略。这些实验将揭示哪些方面拥挤是最具可塑性的，并测试感官适应的新功能益处。我们的共同目标将是对拥挤的神经基础进行全面的研究，提供发展所需的知识缓解拥挤引起的生活质量问题的治疗和行为策略。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Statistical methods for dissecting interactions between brain areas.

DOI：
10.1016/j.conb.2020.09.009
发表时间：
2020-12
期刊：
Current opinion in neurobiology
影响因子：
5.7
作者：
Semedo JD;Gokcen E;Machens CK;Kohn A;Yu BM
通讯作者：
Yu BM

Feature representation under crowding in macaque V1 and V4 neuronal populations.

DOI：
10.1016/j.cub.2022.10.049
发表时间：
2022-12-05
期刊：
CURRENT BIOLOGY
影响因子：
9.2
作者：
Henry, Christopher A.;Kohn, Adam
通讯作者：
Kohn, Adam

Feedforward and feedback interactions between visual cortical areas use different population activity patterns.

DOI：
10.1038/s41467-022-28552-w
发表时间：
2022-03-01
期刊：
Nature communications
影响因子：
16.6
作者：
Semedo JD;Jasper AI;Zandvakili A;Krishna A;Aschner A;Machens CK;Kohn A;Yu BM
通讯作者：
Yu BM

Limited Evidence for Sensory Prediction Error Responses in Visual Cortex of Macaques and Humans.

猕猴和人类视觉皮层感官预测错误反应的证据有限。