NEURAL VISUAL CODING: IMAGE TO OBJECT REPRESENTATION

描述(申请人提供)：需要资金继续我们对视觉皮质中图像解析机制的研究。V2中的对比度边界响应对于图形-背景方向(边界所有权编码)是选择性的。这项研究的目的是了解这种神经边界所有权表征在视觉过程中的作用。确定了未来五年的三大目标： 首先，分析了边界所有权分配的机制。有证据表明，边界所有权信号反映的图像语境远远超出了传统接受场的范围，但出现的潜伏期很短，不需要注意。其目的是研究全局形状的影响：(1)通过使用其中一些关键特征(曲率、角点、X-和T-结)被可变遮挡的显示器，并分析作为暴露特征的函数的边界所有权信号，以及(2)通过向低对比度图形添加视觉噪声并将噪声模式与边界所有权信号相关来研究全局形状影响。 第二个目标是研究边界所有权信号的动态，它的上升时间和持久性，是否存在边界所有权的记忆或信号是否被动衰减，以及当图形移动时，边界所有权分配是否保持。注视任务将用于AIMS 1-2。 第三个目标是研究图像解析阶段在视觉认知中作为自上而下过程的接口的作用。为了研究边界所有权信号与选择性注意的交互作用，将训练猴子对部分重叠的图形执行形状辨别，因此正确执行任务需要分配边界所有权。为了确定中央过程是否可以影响视觉皮质中的图形背景表征，将在猴子执行视觉搜索任务时研究边界所有权信号。研究将集中在V2区，但也将探索V1和V4区。

DESCRIPTION (provided by applicant): Funds are requested to continue our studies of image parsing mechanisms in the visual cortex. Contrast border responses in V2 are selective for figure-ground direction (border ownership coding). The aim of the proposed research is to understand the role of this neural border ownership representation in the visual process. Three broad aims are identified for the next five years: The first is to analyze the mechanisms in border ownership assignment. Evidence shows that border ownership signals reflect the image context far beyond the scope of the conventional receptive field, but emerge with short latency and do not require attention. The aim is to study the global form influence (1) by using displays in which some critical features (curvature, corners, X- and T-junctions) are variably occluded, and analyzing the border ownership signal as a function of the exposed features, and (2) by adding visual noise to a low-contrast figure and correlating the noise pattern with the border ownership signal. The second aim is to study the dynamics of the border ownership signal, its rise time and persistence, whether there is memory for border ownership or if the signal decays passively, and whether border ownership assignment is preserved when a figure is moved. The fixation task will be used for aims 1-2. The third aim is to study the role of the image parsing stage as an interface for top-down processes in visual cognition. To study the interaction of border ownership signals with selective attention, monkeys will be trained to perform shape discrimination with partially overlapping figures, so that correct performance of the task requires border ownership assignment. To determine if central processes can influence the figure ground representation in the visual cortex, border ownership signals will be studied while the monkey is performing a visual search task. The studies will focus on area V2, but areas V1 and V4 will also be explored.