Functional Architectural of Area V4

V4区功能建筑

• 批准号: 7583769
• 负责人: Daniel Jay Felleman
• 金额: $ 35.14万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7583769
• 关键词: Architecture; Area; Attention; Brain Injuries; Characteristics; Classification; Color; Complex; Contracts; Detection; Development; Electrodes; Exhibits; Goals; Image; Individual; Investigation; Knowledge; Maps; Memory; Methods; Microelectrodes; Neurons; Ocular Prosthesis; Optical Methods; Pattern; Population; Primates; Process; Property; Research; Sampling; Scheme; Shapes; Site; Spatial Distribution; Stimulus; Structure; Sum; Temporal Lobe; Tracer; V4 neuron; Vision; Visual; Visual Cortex; Visually Impaired Persons; area V1; area V4; base; color constancy; extrastriate visual cortex; functional loss; luminance; monocular; novel; object recognition; orientation selectivity; preference; research study; response; vector; visual memory; visual process; visual processing

Area V4 is a key component of primate visual cortex that is involved in many aspects of ‘intermediate’ processing including higher-order shape processing, color constancy, and attention. V4 performs more complex computations than lower areas V1 or V2, but it does not complete object analysis that occurs in the temporal lobe. Despite considerable knowledge about the properties of individual V4 neurons, little is known about how simple and more complex visual features are represented by populations of neurons in V4. Recent experiments indicate that V4 orientation-preferred regions consist of small iso-orientation clusters that systematically shift to form orientation maps. Similarly, V4 color-preferring regions consist of small iso-hue clusters that shift systematically to form pinwheel-, line-, or angle-shaped hue maps. Most importantly, these orientation- and color-preferring maps partially overlap each other, resulting in both color or orientation single-feature modules and color-orientation feature-conjunction modules. In the proposed experiments, intrinsic cortical imaging will determine quantitatively, how preferred color and orientation preference and selectivity are represented in V4 and whether these features are organized into single-feature and feature-conjunction modules. Electrophysiological recording will determine the neuronal bases of these feature maps. Since V4 modules are expected to be small (~0.5-1 mm across), closely spaced microelectrode arrays will optimize the detection of systematic differences in neuronal color and orientation tuning across the cortex. V4 receives dense, largely segregated inputs from V2 thin and interstripes that are thought to convey color and shape information, respectively. However, it remains largely unknown how these inputs contribute to the neuronal properties and functional architecture of V4. In these experiments, distinguishable neuroanatomical tracers will be injected into two or more functionally characterized V4 modules to determine their specific patterns of connections with V2. The long-term goal of this research is to determine how different visual features are represented at different hierarchical levels of visual cortex and to determine how these architectures contributes to object recognition and memory.

V4 区是灵长类动物视觉皮层的关键组成部分，涉及“中间”处理的许多方面，包括高阶形状处理、颜色恒定性和注意力。 V4 比下部区域 V1 或 V2 执行更复杂的计算，但它不能完成颞叶中发生的对象分析。尽管人们对单个 V4 神经元的特性有了相当多的了解，但对于 V4 神经元群如何表示简单和更复杂的视觉特征却知之甚少。最近的实验表明，V4 方向优先区域由小的等方向簇组成，这些簇系统地移动以形成方向图。类似地，V4 颜色偏好区域由小的等色调簇组成，这些簇会系统地移动以形成风车形、线形或角形色调图。最重要的是，这些方向和颜色偏好图彼此部分重叠，从而产生颜色或方向单一特征模块和颜色方向特征联合模块。在所提出的实验中，内在皮质成像将定量确定 V4 中如何表示首选颜色、方向偏好和选择性，以及这些特征是否被组织成单一特征和特征连接模块。电生理记录将确定这些特征图的神经元基础。由于 V4 模块预计较小（直径约为 0.5-1 毫米），因此紧密排列的微电极阵列将优化对整个皮层神经元颜色和方向调整的系统差异的检测。 V4 接收来自 V2 细条纹和间条纹的密集且很大程度上隔离的输入，这些输入被认为分别传达颜色和形状信息。然而，这些输入如何影响 V4 的神经元特性和功能架构仍然很大程度上未知。在这些实验中，可区分的神经解剖学示踪剂将被注入两个或多个功能表征的 V4 模块中，以确定它们与 V2 的特定连接模式。这项研究的长期目标是确定不同的视觉特征如何在视觉皮层的不同层次上表示，并确定这些架构如何有助于物体识别和记忆。