MECHANISMS OF BRIGHTNESS PERCEPTION AND FILLING-IN

描述：在过去的三十年里，视觉处理的研究 揭示了神经元通常最受亮度模式的驱动 对比度而不是亮度本身。从主要视觉开始进步 大脑皮层到许多视觉区域，这些区域延伸到顶叶和 颞叶，最佳刺激往往涉及更复杂的 随着感受野尺寸的增大，亮度对比度的排列。 视觉神经元对亮度对比模式的反应 建议我们通过活动的模式来观察视觉形式 许多神经元对亮度对比的模式很敏感。一位伟大的 仍然存在的谜团是我们如何看待除形式之外的任何事物， 具体地说，对象的表面属性，如其 亮度、颜色和质地。大量的心理物理 实验证明，对这些表面的感知 属性很大程度上依赖于亮度和 色度边界。然而，表面的神经过程 属性的计算几乎完全未知。这项研究 在本应用程序中提出的目的是通过聚焦 关于亮度感知。这项研究的长期目标是 了解视皮层中神经元的反应和 相互作用，产生视觉感知。为了实现这一目标， 传统上用于心理物理实验的刺激被用来 研究视觉神经元对表面特性的反应。这个 亮度信息的表示将在 皮质区V1和V2以及LGN和视束。录音 在这些站点中的每一个制作将在视觉上确定在什么阶段 处理与亮度相关的神经活动起源于。 将使用细胞色素氧化酶染色来确定亮度 相关的神经活动被限制在特定的 V1和V2被认为是并行处理流的组件。通过 测量对不同式样制服的反应的时间进程 照亮后，假设将被检验，有明显的快 以及大脑皮质亮度计算中的慢成分。通过 它采用了从知觉研究中借用的一系列视觉刺激， 将确定是否有神经元以某种方式激发 与亮度相关，而与刺激的类型无关。

DESCRIPTION: Research on visual processing in the past thirty years has revealed that neurons are usually best driven by patterns of luminance contrast rather than luminance itself. Progressing from primary visual cortex to the numerous visual areas that stretch toward the parietal and temporal lobes, optimal stimuli tend to involve more complex arrangements of luminance contrast as receptive fields increase in size. The responses of visual neurons to patterns of luminance contrast suggest that we see visual form by the pattern of activity across a great many neurons sensitive to patterns of luminance contrast. A great mystery that remains is how we see anything other than form, specifically, the surface properties of objects such as their brightness, color, and texture. A large number of psychophysical experiments have demonstrated that the perception of these surface attributes is strongly dependent on information at luminance and chromatic boundaries. However, the neural processes by which the surface properties are computed are almost entirely unknown. The research proposed in this application aims to uncover these processes by focusing on brightness perception. The long-term goal of this research is to understand the manner in which neurons in visual cortex respond and interact, giving rise to visual perception. To achieve this goal, stimuli traditionally used in psychophysical experiments are used to examine the responses of visual neurons to surface properties. The representation of brightness information will be investigated in cortical areas V1 and V2 as well as the LGN and optic tract. Recordings made at each of these sites will establish at what stage in visual processing neural activity correlated with brightness originates. Cytochrome oxidase staining will be used to determine whether brightness associated neural activity is restricted to particular compartments of V1 and V2 thought to be components of parallel processing streams. By measuring the time course of responses to various patterns of uniform illumination, the hypothesis will be tested that there are distinct fast and slow components in the cortical computation of brightness. By employing a range of visual stimuli borrowed from perceptual studies, it will be established whether there are neurons that fire in a manner correlated with brightness irrespective of the type of stimulus.