Central and Peripheral Processes in Visual Adaptation

视觉适应的中枢和外围过程

• 批准号: 6650242
• 负责人: STEVEN K SHEVELL
• 金额: $ 30.5万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6650242
• 关键词: behavioral /social science research tag; binocular vision; brightness discrimination; clinical research; color visions; form /pattern perception; human subject; light adaptations; light intensity; neural information processing; psychophysics; retinal adaptation; space perception; visible light; vision tests; visual fields; visual pathways; visual perception; visual stimulus

DESCRIPTION (Provided by applicant): Color is a fundamental aspect of vision. Color is not in light but rather in the neural representation of light in eye and brain. This neural representation, and therefore the perceived color of a light, depends on the context of other lights also in view. Classically, context has been studied with uniform backgrounds. The proposed research investigates neural processes of color perception using context that has spatial structure. Spatial structure of context is a basic property affecting color appearance. For example, recent results from my laboratory show that the color of a light can be shifted substantially more by introducing a background pattern composed of two chromaticities than by a uniform background at either of the two chromaticities in the pattern. A fundamental unsolved problem, which is addressed by this research, is the level(s) of neural representation where context with spatial structure affects color perception. This is a central issue for understanding perception of natural scenes, in which most objects are seen within a complex patchwork of other light. In general, context can induce two qualitatively distinct types of shift in perceived color, either away from the appearance of nearby context (color contrast) or toward it (color assimilation). Initially, contextual patterns will be selected to study separately the neural processes that mediate contrast and that mediate assimilation. Later studies will integrate these results to achieve a broader understanding of color perception with more general types of context with spatial structure. Neural processes that mediate color vision will be inferred by measuring changes in the perceived color of a light caused by introducing strategically designed surrounding patterns. The experiments are devised to distinguish among competing hypotheses of neural representation (for example, receptor signals, postreceptoral chromatically-opponent neural pathways, or more chromatically selective, higher-order central mechanisms). Reduced color vision in patients typically is assessed with tests that use simple visual fields. Neural mechanisms affected only by complex spatial structure, which occurs in natural viewing, are not evaluated. A long-term goal of this research is to understand the many neural processes mediating color perception of complex visual stimuli, and to develop methods to assess the functioning of these neural mechanisms.

描述（由申请人提供）：颜色是视觉的一个基本方面。 颜色不是光，而是眼睛对光的神经表征。 和大脑。这种神经表征，以及因此感知到的颜色， 光，取决于其他灯的背景也在考虑。传统上， 上下文已经在统一的背景下进行了研究。拟议研究 研究神经过程的颜色感知使用上下文， 空间结构背景的空间结构是影响色彩外观的基本属性。例如，我的实验室最近的结果表明， 通过引入背景，灯光的颜色可以发生更大的变化 由两个色度组成的图案，而不是由任何一个色度的统一背景组成的图案 两种色度的对比一个根本的未解决的问题， 是由这项研究解决的，是神经表征的水平， 具有空间结构的背景影响颜色感知。这是一个中央 理解自然场景感知的问题，其中大多数物体都是 在其他光线的复杂拼凑中看到的。 一般来说，语境可以引起两种性质不同的转换， 感知的颜色，或者远离附近环境的外观（颜色 对比）或朝向它（颜色同化）。最初，上下文模式 将被选择来分别研究调节对比度的神经过程 并调节同化。随后的研究将整合这些结果， 实现更广泛的理解颜色感知与更一般类型的 空间结构的背景。 调节色觉的神经过程将通过测量 由于策略性地引入光而引起的光的感知颜色的变化 设计周围的图案。这些实验旨在区分 神经表征的竞争假设（例如，受体信号， 感受器后染色-对立神经通路，或更多染色 选择性的、高阶的中枢机制）。 患者色觉减退通常通过使用以下测试进行评估： 简单的视野神经机制只受复杂的空间 结构，这发生在自然观察，不进行评估。一个长期目标 这项研究的目的是了解许多神经过程介导的颜色 感知复杂的视觉刺激，并制定方法来评估 这些神经机制的功能。