The Tuning for Complex Visual Stimuli in V1

V1 中复杂视觉刺激的调整

• 批准号: 6910610
• 负责人: ANIRUDDHA DAS
• 金额: $ 40.88万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-07 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6910610
• 关键词: Macaca; brain mapping; cell cell interaction; electrical measurement; electrodes; imaging /visualization /scanning; neural information processing; neurons; optics; retina; sensory receptors; single cell analysis; visual cortex; visual perception; visual stimulus

DESCRIPTION (provided by applicant): The long-term goal of this work is to understand the neural mechanisms of visual form perception. The current project aims to study the processing of modestly complex visual stimuli such as smooth contours, junctions and texture boundaries in primary visual cortex (V1). Recent evidence suggests that V1 is much more than just a bank of filters that passively extracts the simplest elements (e.g. short oriented line segments) from all visual input, as was earlier believed. Rather, the elemental components of complex stimuli interact strongly with each other to give V1 responses that could differ dramatically from the responses to the individual components. The current project is intended to test the hypothesis that such complex visual processing can be predicted from the columnar architecture and intrinsic circuitry of VI. In particular, it is proposed that cortical columns tuned to elemental components of a complex stimulus (e.g. line segments at particular retinotopic positions, orientations, color contrast etc.) facilitate and inhibit each other in predictable ways through intrinsic V1 circuitry to generate tuning for the composite whole. Further, that the complex tuning of any given V1 neuron can be predicted from its geographical position on cortex relative to columns activated by the complex stimulus in question. This hypothesis will be tested by studying the V1 processing for different families of complex stimuli including smooth contours, junctions and texture boundaries that are perceptually important for scene segmentation. A combination of optical imaging and electrode recordings in alert monkey V1 will be used for this study. Optical imaging will allow for mapping the cortical positions of neurons responding to each complex stimulus and its individual components. Electrode recordings and cross correlations, guided by optical images, will be used to measure the intracortical interactions between the same groups of neurons. The complex tuning computed on the basis of these interactions can then be compared with the measured values and thus test our hypothesis. The proposed combination of optical imaging and electrode recording will make it possible to elucidate the geometry of cortical mechanisms underlying V1 tuning, a goal that is not reachable through electrode recordings alone. The results of this study will provide a broad framework for understanding the cortical processing of complex visual stimuli, an essential step for clinical applications including the design of visual prostheses for the blind.

描述(申请人提供)：这项工作的长期目标是了解视觉形式知觉的神经机制。本课题旨在研究初级视觉皮层(V1)对中等复杂视觉刺激的加工，如平滑轮廓、连接和纹理边界。最近的证据表明，V1不仅仅是一组过滤器，它被动地从所有视觉输入中提取最简单的元素(例如，短定向线段)，正如早先所认为的那样。相反，复杂刺激的基本成分彼此之间有很强的相互作用，从而产生与对单个成分的反应截然不同的V1反应。目前的项目旨在验证这样一个假设，即这种复杂的视觉加工可以从VI的柱状结构和内在电路中预测出来。特别是，有人提出，皮质柱调节到复杂刺激的基本成分(例如，特定视网膜位置、方向、颜色对比度等处的线段)。通过内部V1电路以可预测的方式相互促进和抑制，以生成复合整体的调谐。此外，任何给定的V1神经元的复杂调谐可以根据其在皮质上相对于由所述复杂刺激激活的柱的地理位置来预测。这一假设将通过研究不同的复杂刺激家族的V1处理来验证，这些复杂刺激包括平滑的轮廓、接合点和纹理边界，这些对场景分割具有感知上的重要性。这项研究将结合光学成像和对警觉猴子V1的电极记录。光学成像将允许绘制对每个复杂刺激及其单独组件做出反应的神经元的皮质位置。在光学图像的引导下，电极记录和交叉关联将被用来测量相同神经元组之间的皮质内相互作用。然后，可以将基于这些相互作用计算的复杂调谐与测量值进行比较，从而验证我们的假设。光学成像和电极记录的拟议组合将使阐明V1调谐背后的皮质机制的几何形状成为可能，这是仅通过电极记录无法达到的目标。这项研究的结果将为理解复杂视觉刺激的皮质处理提供一个广泛的框架，这是临床应用的关键步骤，包括为盲人设计视觉假体。