MECHANISMS OF BRIGHTNESS PERCEPTION AND FILLING-IN

虽然通常认为感知的亮度不是一个 视网膜照明的逐点表示，没有 如何计算亮度的共识。 建议的目标 研究是为了回答以下问题，从而澄清 大脑决定物体亮度的机制。 1.亮度分布的什么函数决定亮度 （亮度本身、边缘对比度、所有空间尺度的对比度）？ 边缘在决定亮度方面是否起着特殊的作用？ 是什么 一种神经过程或表现，形成一个均匀的反射区域 看起来亮度均匀吗 2.亮度的时间特性是什么？ 亮度是否 扩散？ 3.对于某些类型的亮度调制， 均匀亮度区域的亮度变化似乎滞后于边缘的变化。 这是因为亮度扩散率有限吗？ 是基于 低空间频率滤波器的较慢的时间响应？ 4.看来，随着方波的大小增加， 优先丧失对低空间频率的灵敏度。 因为这 不是因为对比敏感度功能，这是否意味着 有频率交互作用偏向于低频率？ 是 这些相互作用仅仅是基于频率，还是依赖于更高的 顺序结构，例如 方波？ 5.频率特异性相互作用是否与梯度显著相关 像Craik-O 'Brien-Cornsweet效应那样的亮度错觉 这项工作被设想为一个更大的调查的一部分，其目标是 了解大脑是如何表达和处理 物体的表面特性。 因为它们的相似性 亮度和颜色感知之间的关系（例如恒定性，对比度 错觉，同化），这提供了关于亮度的新见解 研究将考虑其可能的适用性， 了解颜色视觉的机制。 另一个长期目标是 调查是使用相同的刺激从心理物理 在生理实验中评估大脑皮层 亮度的代表。

While it is generally recognized that perceived brightness is not a point-by-point representation of retinal illumination, there is no consensus about how brightness is computed. The goal of the proposed research is to answer the following questions, thus clarifying the mechanisms by which the brain determines the brightness of objects. 1. What function of a luminance distribution determines brightness (luminance itself, contrast at edges, contrast at all spatial scales)? Do edges play a special role in determining brightness? What is the neural process or representation that makes a uniformly reflective area appear to have uniform brightness? 2. What are the temporal properties of brightness? Does brightness diffuse? 3. With certain types of luminance modulation, brightness at the center of areas of uniform luminance appears to lag behind changes at the edge. Is this because of the limited rate of brightness diffusion? Is it based on slower temporal responses of low spatial frequency filters? 4. It appears that as squarewaves increase in size, there is a preferential loss of sensitivity to low spatial frequencies. As this isn't because of the contrast sensitivity function, does it mean that there are frequency interactions biased toward low frequencies? Are these interactions simply based on frequency or do they depend on higher order structure such as the phase alignment of components in the squarewave? 5. Are frequency specific interactions significantly involved in gradient brightness illusions such as the Craik-O'Brien-Cornsweet effect? This work is envisioned as part of a larger investigation with the goal of understanding how the brain represents and processes information about the surface properties of objects. Because of the close similarities between brightness and color perception (e.g. constancy, contrast illusions, assimilation), new insights about brightness provided by this study will be considered for their possible applicability to understanding mechanisms of color vision. Another longer range goal of the investigation is to use the same stimuli from the psychophysical studies in physiological experiments to assess the cortical representation of brightness.