Neural Basis of Depth Perception

深度知觉的神经基础

• 批准号: 6359074
• 负责人: GREGORY C DEANGELIS
• 金额: $ 29.45万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-05 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6359074
• 关键词: Macaca mulatta; behavioral /social science research tag; binocular vision; electrostimulus; microelectrodes; motion perception; neural information processing; neurons; single cell analysis; visual cortex; visual depth perception; visual fields; visual stimulus

To effectively guide behavior in a three-dimensional (3D) world, the visual system must create a 3D representation of one's surroundings. Each retinal image is simply a two- dimensional projection of 3D space, and thus contains no explicit depth information. The brain must therefore compute the 3D structure of a scene from the pair of retinal images. Binocular disparities between corresponding features in the two images provide precise, quantitative information about 3D scene structure, and these disparities are known to be encoded by neurons in primary visual cortex (V1). Recent studies show, however, that the representation of binocular disparity in V1 is not sufficient to account for stereoscopic depth perception. It is therefore critical to understand disparity processing in the extrastriate visual areas to which V1 projects. The goal of this research is to understand how disparity signals emanating from V1 are processed, transformed, and read out of extrastriate cortex to mediate stereoscopic depth perception. Our preliminary studies suggest that cortical area MT plays an important role in this process. The proposed experiments are designed to explore the nature of the disparity representation in MT, and to evaluate the contributions that MT makes to depth discrimination. There are four specific aims. The first aim is to determine whether MT neurons signal absolute or relative disparities. Relative disparities are critical for depth perception, but V1 neurons encode only absolute disparities. The second aim is to establish whether area MT contributes to perceptual discrimination of fine disparities. Single- and multi-unit responses will be recorded while monkeys perform a stereoacuity task, and electrical microstimulation will be used to probe for a causal link between neuronal activity and task performance. The third aim is to determine if MT neurons signal 3D surface orientation defined by gradients of horizontal disparity. The fourth aim is to test whether MT neurons combine horizontal disparity signals with an estimate of viewing distance (derived from vertical disparities) to encode egocentric distance and depth. By helping to elucidate the neurobiological basis of perception, these studies should ultimately lead to new approaches for treating diseases that impair visual cognition. This research should also be helpful for evaluating the design and safety of 3D virtual environments.

为了有效地指导三维（3D）世界中的行为，视觉系统必须创建周围环境的3D表示。 每个视网膜图像只是3D空间的两维投影，因此不包含明确的深度信息。 因此，大脑必须从一对视网膜图像中计算场景的3D结构。 两个图像中相应特征之间的相应特征之间的双眼差异提供了有关3D场景结构的精确定量信息，并且已知这些差异是由主视觉皮层（V1）中的神经元编码的。 然而，最近的研究表明，V1中双眼差的表示不足以说明立体深度感知。 因此，重要的是要了解V1向其项目的外部视觉区域中的差异处理。 这项研究的目的是了解如何处理，转化和读取从v1发出的差异信号，以介导立体深度感知。 我们的初步研究表明，皮质区域MT在此过程中起着重要作用。 提出的实验旨在探索MT中差异表示的性质，并评估MT对深度歧视的贡献。 有四个具体目标。 第一个目的是确定MT神经元是否信号绝对或相对差异。 相对差异对于深度感知至关重要，但是V1神经元仅编码绝对差异。 第二个目的是确定地区MT是否有助于对罚款差异的感知歧视。 将记录单单元和多单位响应，而猴子执行立体式任务，并且电动微刺激将用于探测神经元活动和任务性能之间的因果关系。 第三个目的是确定MT神经元是否信号3D表面取向由水平差异定义。 第四个目的是测试MT神经元是否将水平差异信号与观看距离估计（从垂直差异得出）结合在一起，以编码以自我为中心的距离和深度。 通过帮助阐明感知的神经生物学基础，这些研究最终应导致治疗损害视觉认知疾病的新方法。 这项研究还有助于评估3D虚拟环境的设计和安全性。