Mechanisms of Color Detection, Induction and Adaptation

描述（由申请人提供）：可能色觉最重要的功能是通过光源识别物体和材料，以及通过一系列物体识别光源。在色彩恒定的文献中，几乎所有的实验工作和大多数计算模型都表明，神经系统应该忽略光源，这样物体的颜色才会显得恒定。然而，这个项目是基于对比观察，在许多情况下，物体在不同的光源下确实呈现出系统的不同颜色。当光源光谱发生变化时，反射光光谱的变化会导致所有自然物体的锥吸收发生类似的倍增变化。使用真实和模拟的刺激，我们将询问观察者是否可以使用这些变化来识别物体和光源，使用外观的相似性或外观变化的比较。在不同光源的识别依赖于比较物体的颜色变化和背景的颜色变化的地方，我们将推导出所使用的几何颜色关系。我们将通过使用定理作为一致性检查来研究感知色彩空间的内在几何，并测试其对光源变化的不变性。世界上大多数物体的颜色都不是统一的，所以我们将测试有图案的物体，看看局部对比的识别是否有助于识别材料。当只有单一光源存在时，外观的稳定性是材料识别的最佳线索。我们将测试恒定机制是否在空间上延伸，还是在空间上局部但在时间上延伸，并测试结果是否需要适应模型或感知参考框架。我们将直接测量光源的感知颜色，识别用于该估计的场景统计，并测试该估计是否用于颜色常数。该项目的结果将为日常色彩任务的神经计算和表征提供见解。这里开发的方法将有助于识别色觉缺陷的功能后果

DESCRIPTION (provided by applicant): Possibly the most important functions of color vision are the identification of objects and materials across illuminants and of illuminants across sets of objects. In the color constancy literature, almost all experimental work and most computational models suggest that the nervous system should discount the illuminant so that colors of objects appear constant. This project, however, is based on the contrasting observation that, in many situations, objects do appear to be of systematically different colors under different illuminants. When the illuminant spectrum changes, changes in the spectra of reflected lights result in similar multiplicative changes in cone absorptions for all natural objects. Using real and simulated stimuli, we will ask whether observers can use these shifts to identify objects and illuminants, using similarity of appearance or comparisons of shifts in appearance. Where identification across illuminants depends on comparing color changes in objects to color changes in backgrounds, we will derive the geometric color relations that are used. We will study the intrinsic geometry of perceptual color space by using theorems as consistency checks, and test its invariance to illuminant changes. Most objects in the world are not uniform in color, so we will test patterned objects to see whether identification of local contrasts helps in identifying materials. When only a single illuminant is present, constancy of appearance is the best cue for material identification. We will perform tests of whether constancy mechanisms extend over space or are spatially local but extend across time, and also test whether the results require models of adaptation or perceptual frames of reference. We will directly measure the perceived color of the illuminant, identify the scene statistics that are used in this estimation, and test if this estimate is used in color constancy. The results of this project will provide insights into neural computations and representations underlying everyday color tasks. The methods developed here will be useful in identifying functional consequences of color vision deficits