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CONTRAST, CONTEXT AND STIMULUS GROUPING IN STRIATE CELLS

纹状细胞中的对比度、背景和刺激分组

基本信息

批准号：
6179174
负责人：
TAKUJI KASAMATSU
金额：
$ 28.57万
依托单位：
SMITH-KETTLEWELL EYE RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
1997
资助国家：
美国
起止时间：
1997-04-01 至 2002-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6179174
关键词：
behavioral /social science research tag cats form /pattern perception microelectrodes neural information processing neurophysiology single cell analysis space perception visual cortex visual depth perception visual perception visual stimulus

项目摘要

Gestalt perceptual theory says that the visual system groups features together on the basis of similarity, proximity, smoothness and closure. Recent psychophysical and neurophysiolgical studies have found evidence of spatial facilitation and suppression that appears to conform to the perceptual grouping rules. The perceptual grouping may be implemented by long-range lateral connections in visual cortex. Recently, we found that single-cell responses to a central target were modulated by collinear flanking objects. This modulation was dependent on the cell's contrast threshold for the central target. We hypothesized that the lateral interactions in area 17 are arranged into two antagonistic mechanisms: 1) Facilitation is spatially organized along the optimal orientation of the cell in a collinear manner; 2) Suppression is non-selective for orientation or spatial frequency, and is distributed diffusely around the cell's response field. The balance between these two mechanisms, dictated by the cell's contrast threshold, controls the cells firing. Based on this hypothesis, we will study the following four questions by physiological recording of single cells from the visual cortex of anesthetized and paralyzed preparations. Aim l will answer the question whether the context-dependent modulation of cellular responses depends on contrast relative to the cell's contrast threshold, rather than on the physical contrast of the stimulus. We want to know how general the contrast threshold-dependent facilitation and suppression is. Aim 2 will dissect the spatial organization of the modulatory interactions. In particular, we will elucidate an organizational principle along the optimal orientation of the cell under study. Aim 3 will study effects of distance between target and flanks, flanks size, and their spatial frequency on the modulatory interactions. This aim is focused on an issue of similarity and closeness of target and flanks. Aim 4 will extend our search of the neural basis of perceptual grouping one step ahead, using compound stimuli made of many elements in curve. We will answer whether single cells respond differently when the optimally positioned test stimulus is a part of a smoothly curved path or circle composed of many of the same patterns as the test patch.

完形知觉理论认为，视觉系统将特征组合在一起在相似、接近、平滑和闭合的基础上聚集在一起。最近的心理物理和神经生理学研究发现了证据空间促进和抑制似乎符合感性分组规则。感知分组可以通过以下方式来实现视皮层中的远距离侧向连接。最近，我们发现，单细胞对中心靶点的反应受共线调节侧翼的物体。这种调制取决于细胞的对比度中央目标的阈值。我们假设侧向的区域17中的相互作用被安排成两种对抗机制： 1)促进是沿着以下最佳方向在空间上组织的共线方式的单元格；2)抑制对于方向性或空间频率，并广泛分布在单元格的响应字段。这两种机制之间的平衡，决定了通过细胞的对比度阈值，控制细胞的激发。基于在这一假设下，我们将通过以下四个问题进行研究大鼠视皮层单个细胞的生理记录麻醉和麻痹的制剂。目的L将回答这样一个问题：语境依赖的调制是否细胞的反应取决于相对于细胞对比度的对比度阈值，而不是刺激的物理对比度。我们要要了解对比度阈值依赖的促进和压制才是。目标2将剖析调制的空间组织互动。特别是，我们将阐明一个组织沿着被研究细胞的最优取向的原则。目标3将研究目标与侧翼、侧翼之间的距离的影响大小以及它们的空间频率对调制相互作用的影响。这 AIM的重点是目标和目标的相似性和贴近性问题侧翼。目标4将扩展我们对知觉分组的神经基础的研究领先一步，使用由曲线上的许多元素组成的复合刺激。我们将回答单个细胞在最佳情况下是否有不同的反应定位测试刺激是平滑曲线路径或圆的一部分由许多与测试贴片相同的图案组成。