Central and Peripheral Processes in Visual Adaptation

描述（由申请人提供）：本研究的目的是了解在自然观看中调节颜色和亮度感知的神经通路。色彩与亮度的匹配、辨别和呈现已经在简单的视野中得到了广泛的研究，但在复杂、动态的自然场景中，对物体的色彩感知却知之甚少。简单的字段会严重低估环境对颜色和亮度的影响。即使对颜色恒常性的研究也主要关注光照变化下的颜色感知。相比之下，这里的每条研究线都侧重于在一个复杂的背景下，随着空间和/或时间的变化而变化的色彩感知。有五条研究路线，每一条都是为了揭示视觉的基本原理，这些原理介导了对复杂场景的感知。第一个测试用不均匀的彩色背景图案测试颜色感知的神经表征。目的是了解任何空间色彩模式的色彩感知。第二项研究视网膜分离区域的整合，所有这些区域都受到单一物体的刺激。分离的区域是由于前景中其他物体的部分遮挡造成的。感知分组将分离的区域整合在一起，因此人们看到的是单个物体，但分组也会影响颜色感知。第三条研究线检查颜色与形状的感知绑定。物体有许多属性，如形状、深度、运动方向和颜色。为了感知一个统一的对象，这些属性必须集成在一起。这项研究使用了一种新颖的，最近发现的范式，它在颜色绑定中给出了清晰和持续的错误。这个范例被用来测试将颜色与形状结合的其他理论。第四行作品考察了背景光的时间性变化。在经典研究中，简单的时间变化背景无法解释在实验室之外可能发生的更复杂的时间模式的影响。原因是神经非线性，这将是本研究的特点。第五组实验测试了超长时间（几天或几周）色彩适应的替代理论，这反映了自然观看中隐含的神经可塑性。在许多天内颜色外观的逐渐变化表明对色彩环境的适应。每一项研究都调查了颜色和亮度感知的基本神经过程，这些过程既没有被很好地理解，也没有被目前的临床试验评估。许多潜在的神经过程是皮层的。对复杂场景中综合物体的感知是正常视觉的一个基本方面。这项研究为诊断程序提供了必要的基础，可以揭示以前未识别的视觉处理缺陷。对颜色和亮度的心理物理测量将检验其他理论。定量建模将纳入生理研究的视觉通路特征。

DESCRIPTION (provided by applicant): The aim of this research is to understand neural pathways that mediate color and brightness perception in natural viewing. Matching, discrimination and appearance of color and brightness have been studied extensively with simple visual fields but little is known about the color perception of objects within complex, dynamic scenes typical of natural viewing. Simple fields can severely underestimate the influence of context on color and brightness. Even studies of color constancy are concerned mainly with color perception under changes of illumination. By comparison, each line of research here focuses on color perception within a complex context that varies over space and/or time. There are five lines of research, each chosen to reveal fundamental principles of vision that mediate perception of complex scenes. The first tests neural representations for color perception with inhomogeneous chromatic background patterns. The aim is to understand color perception with any spatiochromatic pattern. The second investigates integration of retinally separated regions, all of which are stimulated by a single object. The separated regions result from partial occlusion by other objects in the foreground. Perceptual grouping integrates the separated regions so one sees a single object but grouping also affects color perception. The third line of research examines perceptual binding of color to form. An object has many attributes such as shape, depth, direction of motion and color. The attributes must be integrated for the percept of a unified object. This research uses a novel, recently discovered paradigm that gives clear and sustained errors in color binding. The paradigm is leveraged to test alternative theories of binding color to form. The fourth line of work examines temporally varying background light. Simple temporally varying context, as in classical studies, fails to explain the influence of more complex temporal patterns that can occur outside the laboratory. The cause is a neural nonlinearity, which will be characterized by this study. The fifth set of experiments tests alternative theories of very-long-term chromatic adaptation (over days or weeks), which reflects neural plasticity implicit in natural viewing. Gradual changes in color appearance over many days reveal adaptation to the chromatic environment. Each line of research investigates basic neural processes of color and brightness perception that are neither well understood nor assessed by current clinical tests. Many of the underlying neural processes are cortical. Perception of integrated objects within complex scenes is a fundamental aspect of normal vision. This research provides essential underpinnings for diagnostic procedures that can reveal previously unidentified deficits in visual processing. Psychophysical measurements of color and brightness will test alternative theories. Quantitative modeling will incorporate characteristics of visual pathways from physiological studies.