Inter-Areal Cooperativity & Visual Contours Perception

描述(由申请人提供)：本研究计划的目标是 了解初级视觉皮质(V1)和次级视觉皮质的作用 区域(V2)在真实和虚幻的亮度知觉中。在以前的支持中 周期中，我们研究了真实和虚幻轮廓处理的组织 猕猴视皮层V1和V2的区域。我们发现这些信号 在处理真实轮廓的过程中，V1和V2相似，但是 在虚幻轮廓的过程中相互补充(Ramsden等人，2001年)。这些 研究结果可能表明，轮廓同一性的编码依赖于 多个皮质区域的协同激活。在此支持周期中，我们 建议检验加工的真实和虚幻的亮度是否存在 与真实和虚幻的轮廓处理有什么相似之处。 我们对表面亮度的感知既由绝对亮度决定 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(Rossi et.)的第17区可观察到侧翼区域。等人，1996年； Rossi&Paradiso，1999)。尽管这证明了亮度感知 由于表面亮度的原因，对比度可以早在初级视觉中实现 大脑皮层，目前尚不清楚对比边界是否也对此有影响 亮度响应。在这里，我们建议检查一个神经加工 边界诱导的亮度感知，克雷克-奥布莱恩-康斯威特错觉。vbl.使用 电生理和光学成像方法，我们的目标是检查 猫和猴的V1和V2对真实和边界诱导的反应 亮度刺激。我们的目标是在V1和V2定位皮质隔室 参与了真实和虚幻的亮度处理。此外，我们还将 通过研究单个单元的响应，确定真实的 和幻觉反应，以及幻觉反应的空间范围 大脑皮层。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 感知力。

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.