CENTRAL AND PERIPHERAL PROCESSES IN VISUAL ADAPTATION

描述：(摘自首席研究员的摘要)对颜色的感知 取决于眼睛和大脑的神经过程。图像的颜色和亮度 单一的、孤立的光都与S物理上的光密切相关 特征，但相同的光可能被认为具有非常 当作为综合体的一部分查看时，颜色和亮度外观不同 场景。视觉中一个基本的悬而未决的问题是颜色和 灯光的亮度外观取决于其他刺激的上下文 查看。虽然以前的研究已经考虑了这个问题，但大多数研究 使用了非常简单的视觉刺激，例如叠加在 均匀的背景或在均匀的周围区域内。这项工作有 揭示了影响颜色感知的基本机制，但没有考虑 依赖于视觉刺激的重要神经过程 比统一的背景或环境复杂的。最近的研究表明， 颜色感知强烈地依赖于即使是稀疏的表现 适度复杂、不均匀的视觉刺激中的色度。 拟议的研究将评估颜色的基本属性和 通过测试特定假设在复杂场景中的亮度感知 关于神经机制的空间、时间和色度特征。 这些神经机制的生理轨迹也将是 调查过了。这将通过进行心理物理测量来实现。 与许多不同类型的精心设计的颜色感知 不均匀的场。增量和减量的出现都将 被研究是为了调查所有颜色感知的范围 发生在自然场景中。总体而言，这项研究将研究神经过程 在更接近自然观看的条件下调节颜色外观 比之前大多数研究中研究的都要多。色觉降低 患者通常通过颜色匹配或测试进行评估 使用非常简单的字段的歧视。神经机制仅受影响 通过自然观察中出现的更复杂的场，不进行评估。一个 这项研究的长期目标是全面了解神经过程 调节任意复杂视觉的颜色和亮度知觉 刺激，并开发测试来评估这些神经的功能 机制。

DESCRIPTION: (from principal investigator's abstract) Perception of color depends on neural processes of eye and brain. The color and brightness of a single, isolated light are closely related to the light s physical characteristics, but the same light may be perceived to have a very different color and brightness appearance when viewed as part of a complex scene. A fundamental unsolved problem in vision is how the color and brightness appearance of a light depend on the context of other stimuli in view. While previous research has considered this problem, most studies have used very simple visual stimuli such as a test field superimposed upon a uniform background or within a uniform surrounding field. This work has revealed basic mechanisms affecting color perception but does not consider important neural processes that depend on visual stimulation that is more complex than a uniform background or surround. Recent studies show that color perception depends strongly on even sparsely represented chromaticities within a modestly complex, inhomogeneous visual stimulus. The proposed research will evaluate fundamental properties of color and brightness perception in complex scenes, by testing specific hypotheses concerning neural mechanism spatial, temporal and chromatic characteristics. The physiological locus of these neural mechanisms also will be investigated. This will be achieved by making psychophysical measurements of color perception with many different types of carefully designed inhomogeneous fields. The appearance of both increments and decrements will be studied in order to investigate the full range of color percepts that occur in natural scenes. Overall, this research will study neural processes that mediate color appearance under conditions closer to natural viewing than have been studied in most previous research. Reduced color vision in patients is typically assessed with tests of color matching or discrimination that use very simple fields. Neural mechanisms affected only by more complex fields, as occur in natural viewing, are not evaluated. A long-term goal of this research is to understand fully the neural processes mediating color and brightness perception of arbitrarily complex visual stimuli, and to develop tests to assess functioning of these neural mechanism.