Neural Mechanisms of Visual Crowding

视觉拥挤的神经机制

• 批准号: 10540782
• 负责人: Anirvan S. Nandy
• 金额: $ 43.47万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10540782
• 关键词: Address; Affect; Animals; Area; Attention; Blindness; Cells; Chronic; Clutterings; Crowding; Future; Impairment; Individual; Intervention Studies; Investigation; Knowledge; Location; Macular degeneration; Maps; Mediating; Nature; Neurons; Output; Pathway interactions; Patients; Perception; Performance; Peripheral; Photic Stimulation; Process; Protocols documentation; Radial; Research; Resources; Retina; Saccades; Scotoma; Sensory; Shapes; Signal Transduction; Site; Stimulus; Target Populations; Testing; Time; Vision; Visual; Visual Perception; Visual System; area V4; awake; base; density; excitatory neuron; extrastriate visual cortex; fovea centralis; gaze; inhibitory neuron; interest; neural; neural correlate; neuromechanism; nonhuman primate; novel; object recognition; oculomotor; receptive field; spatiotemporal

Project Summary Visual perception is an active process of information selection. Two critical components of this selection process are the mechanisms of spatial attention and saccadic eye-movements. Attention allows us to deploy limited neural resources for privileged processing of salient stimuli; saccades allow us to bring stimuli of interest to the center of gaze for detailed inspection. The dynamic interplay of attention and saccades is particularly prominent in peripheral vision where inappropriate integration of contextual information has been proposed as one of the underlying mechanisms of visual crowding. Visual crowding is the inability to identify stimuli amidst clutter and is a fundamental bottleneck to object recognition in peripheral vision. It is particularly detrimental in the case of patients with central vision loss such as macular degeneration (MD), since these individuals rely on a peripheral retinal locus (PRL) for object recognition tasks. Crowding zones, the area in visual space over which distractors affect target identification, are markedly elongated along the radial axis aligned with the fovea in normal vision. Crowding zones undergo systematic reorganization in MD patients with an elongated component along the radial PRL axis. Despite decades of research, the neural underpinnings of crowding and that of the elongated shape of crowding zones remain unknown. In this proposal we will bridge these knowledge gaps in the context of the activity of six neural sub-populations – two cell classes (inhibitory and excitatory neurons) in three layers (superficial, input, deep) – that are fundamental components of the sensory laminar cortical circuit. Our broad hypothesis is that sub-population specific activity dynamics form the substrate for contextual interactions underlying crowding and for the formation and re-organization of crowding zones. We propose to answer several key questions regarding this hypothesis. What are the laminar mechanisms of contextual modulation in crowding zones (Aim 1)? What the spatio-temporal dynamics of peri- saccadic activity in the laminar cortical circuit (Aim 2)? What are the neural mechanisms of crowding zone reorganization following central vision zone (Aim 3)? We will achieve these aims using high-density laminar neural recordings in visual area V4 of awake non-human primates. V4, a critical node in the object recognition pathway, that also receives strong attention related and oculomotor signals, is ideally suited for these investigations. The results of these investigations will uncover the neural mechanisms of crowding, provide a broad framework for visual form processing in the periphery and inform possible future intervention studies in central vision loss.

项目摘要 视觉感知是信息选择的主动过程。此选择的两个关键组成部分 过程是空间注意力和伴随眼动的机制。注意使我们能够部署 有限的神经资源可用于特权处理显着刺激；扫视使我们能够带来 凝视中心的兴趣进行详细检查。注意力和扫视的动态相互作用是 在外围视野中特别突出，在不当的上下文信息整合已经存在的情况下 提议是视觉拥挤的基本机制之一。视觉拥挤是无法识别的 在混乱中刺激，是外围视力中对象识别的基本瓶颈。特别是 对于中央视力丧失的患者（例如黄斑变性（MD））有害，因为这些 个人依靠外围视网膜基因座（PRL）进行对象识别任务。拥挤区，区域 干扰物影响目标识别的视觉空间沿着径向轴明显伸长 在正常视力下与中央凹保持一致。 MD患者在系统重组下的拥挤区域 沿着径向PRL轴的细长成分。尽管进行了数十年的研究，但神经的基础 拥挤和拥挤区的细长形状仍然未知。在这个建议中，我们将桥梁 这些知识差距在六个神经子群的活动的背景下 - 两个细胞类别（抑制 和兴奋性神经元）分为三层（表面，输入，深） - 它们是基本组成部分 感觉层状皮质回路。我们广泛的假设是亚人口特定的活性动力学形成了 基于拥挤的背景互动的基板以及人拥挤的形成和组织 区域。我们建议回答有关此假设的几个关键问题。什么是层流 拥挤区域中情境调制的机制（AIM 1）？周日的空间时空动力学 层状皮质回路中的saccadic活性（AIM 2）？拥挤区的神经机制是什么 中央视觉区域的重组（目标3）？我们将使用高密度层流实现这些目标 视觉区域V4的神经记录。 V4，对象识别中的关键节点 途径也受到强烈关注和眼动物信号的途径非常适合这些 调查。这些调查的结果将发现拥挤的神经机制，提供 外围视觉形式处理的广泛框架，并为未来的干预研究提供信息 中央视力损失。