COOPERATIVE INTERAREAL PROCESSING OF VISUAL CONTOURS

哺乳动物大脑皮层的特征是多个皮质 区域，每个区域都有一个单独的感官世界表示。然而， 多重表征在感觉信息加工中的作用是 未知。作为了解多个皮质区域如何 协同处理视觉感知，本提案旨在研究 V2(第二视觉皮质区域)内的轮廓表示 它与V1(主要视觉)中的轮廓表示的交互 大脑皮层)。众所周知，V1中的定向选择细胞是 响应于亮度对比度边缘。然而，许多视觉轮廓是 不是由亮度对比度定义的，而是由更高阶的特征定义的 (例如遮挡轮廓或纹理图案边框)。V2区， 视觉皮层处理的第二个主要阶段，其特征是 更喜欢这种高阶特征的细胞。这项提案将探讨 认为不同的皮质区域处理不同的水平或 视觉轮廓的抽象，并研究它们是如何分开的 表示法相互作用。具体地说，组织和互动 响应真实轮廓的细胞和响应更高轮廓的细胞之间的差异 我们将检查订单轮廓。将对这些电路进行检查 共同构成的颜色、形状和视差域中的每一个 V2。所述目标将通过组合使用光学 成像、电生理和解剖学方法。V1-V2交互作用 将同时使用互相关方法和光学成像进行研究 V1-V2对“斑点”刺激(一种功能束)的激活 跟踪方法)；这些将与连接模式进行比较 从解剖学上揭示了。此外，轮廓显著的差异是由于 几何或特征特征是否与刺激有关- 互动模式的相关变化。 通过阐明V1区轮廓知觉的神经回路 和V2，这项研究将提供关于不同皮质 各个领域相互加强相同的信息(即 类似定向的实数和高阶等高线单元)或是否更 存在等级关系，其中一个区域的输出是 用于在另一个领域构建完全不同的表示 (不同方向的实部和高阶等高线之间的相互作用 单元格)。或者，可以在不同的情况下使用不同的策略 背景，一种可能得到与刺激相关的支持的可能性 不同等高线群体的连通性或激活的变化 V2中的细胞。

The mammalian cerebral cortex is characterized by multiple cortical areas, each with a separate representation of the sensory world. However, the role of multiple representation in sensory information processing is unknown. As a prelude to understanding how multiple cortical areas cooperatively process visual percepts, this proposal aims to study contour representation within V2 (the second visual cortical area) and its interaction with contour representation in V1 (primary visual cortex). Orientation selective cells in V1 are well known to be responsive to luminance contrast edges. However, many visual contours are not defined by luminance contrast but rather by higher order features (such as occluded contours or texture pattern borders). Area V2, the second major stage of visual cortical processing, is characterized by cells which prefer such higher order features. This proposal will explore the idea that different cortical areas process different levels or abstractions of visual contours and examine how these separate representations interact. Specifically, the organization and interactions between cells responsive to real contours and those responsive to higher order contours will be examined. These circuitries will be examined for each of the color, form, and disparity domains which together comprise V2. The stated goals will be achieved by using a combination of optical imaging, electrophysiological, and anatomical methods. V1-V2 interactions will be studied with both cross correlation methods and optical imaging of V1-V2 activation in response to "spot" stimuli (a functional tract tracing method); these will be compared with connectivity patterns revealed anatomically. In addition, differences in contour saliency due to geometrical or featural characteristics will he related to stimulus- related changes in interaction patterns. By elucidating the neural circuitry underlying contour perception in V1 and V2, this research will offer insight into whether different cortical areas mutually reinforce the same information (i.e. interactions between similarly oriented real and higher order contour cells) or whether a more hierarchical relationship exists in which the outputs of one area are used to construct a quite different representation in another area (interactions between differently oriented real and higher order contour cells). Alternatively, different strategies could be used under different contexts, a possibility that would be supported by stimulus-related changes in connectivity or activation of different populations of contour cells in V2.