Inter-Areal Cooperativity & Visual Contours Perception

描述（由申请人提供）：本研究提案的目标是 了解初级视觉皮层（V1）和第二视觉皮层的作用 区域（V2）在真实的和虚幻的亮度感知中。在此前的支持 循环，我们研究了真实的和虚幻轮廓处理的组织 在猕猴视觉皮层的V1和V2区域。我们发现信号 在处理真实的轮廓期间，来自V1和V2的 在虚幻轮廓期间互补（Ramsden等人，2001年）。这些 研究结果可能表明，轮廓身份的编码依赖于 协调激活多个皮层区域在这个支持周期中，我们 我建议检查是否处理真实的和虚幻的亮度承担 与真实的和虚幻的轮廓处理的任何相似之处。 我们对表面亮度的感知是由绝对亮度 以及亮度对比度。最近，使用同步对比的研究 刺激建立了对亮度调制的亮度响应， 在猫的17区可以观察到侧翼区（Rossi et.例如，1996年; Rossi & Paradiso，1999）。虽然这表明亮度感知 由于表面亮度对比度可以早在初级视觉 皮质，目前尚不清楚对比边界是否也有助于这一点 亮度响应在这里，我们建议检查的神经处理的一个 边界诱导亮度错觉，即Craik-O 'Brien-Cornsweet错觉。使用 电生理学和光学成像方法，我们的目的是检查 猫和猴的V1和V2对真实的和边界诱导的 亮度刺激我们的目标是定位V1和V2的皮质隔室 参与真实的和虚幻的亮度处理。此外，我们将 通过研究单个单元的响应，确定真实的 和错觉反应，以及错觉反应的空间范围， 皮层通过使用不同的虚幻亮度条件，我们的目标是识别 表面和边界对亮度神经编码的贡献 perception.

DESCRIPTION (Provided by applicant): The goal of this research proposal is to understand the role of primary visual cortex (V1) and second visual cortical area (V2) in real and illusory brightness perception. In the previous support cycle, we investigated the organization of real and illusory contour processing domains in V1 and V2 of the macaque monkey visual cortex. We found that signals from V1 and V2 are similar during the processing of real contours, but complementary during that of illusory contours (Ramsden et al., 2001). These findings may suggest that the encoding of contour identity is dependent on the coordinated activation of multiple cortical areas. In this support cycle, we propose to examine whether the processing of real and illusory brightness bears any parallels with that of real and illusory contour processing. Our perception of surface brightness is determined both by absolute luminance as well as by luminance contrast. Recently, studies using simultaneous contrast stimuli established that a brightness response to luminance modulation of flanking regions can be observed in Area 17 of the cat (Rossi et. al., 1996; Rossi & Paradiso, 1999). Although this demonstrated that brightness percepts due to surface luminance contrast can be implemented as early as primary visual cortex, it remained unclear whether contrast borders also contribute to this brightness response. Here, we propose to examine the neural processing of a border-induced brightness percept, the Craik-O'Brien-Cornsweet illusion. Using electrophysiological and optical imaging methods, we aim to examine the responses of V1 and V2 in both the cat and monkey to real and border-induced brightness stimuli. We aim to localize cortical compartments in V1 and V2 involved in real and illusory brightness processing. In addition, we will determine, by studying single-unit responses, the phase relationships of real and illusory responses, and the spatial extent of illusory response in the cortex. By using different illusory brightness conditions, we aim to identify surface and border contributions to the neural encoding of brightness perception.