BINOCULAR VISION AND DEPTH PERCEPTION

该研究计划旨在了解 灵长类动物大脑皮层的立体视觉机制 深度知觉 实验将在警觉的恒河猴中进行 行为训练重复执行视觉任务，而单身 将用一个或多个微电极记录神经元活动， 纹状和前纹状皮质。 刺激将以立体方式呈现 在左眼和右眼分别看到的两个彩色显示器上，以及 由高速图形系统生成。 一个（或两个）的位置 将持续监测眼睛，以控制猴子的 凝视的方向。 主要目的是获得实验性的 支持或反对这一假设的证据， 的皮层视觉神经元直接与立体深度有关 感知，并确定不同类型的 立体过程中的神经视差选择性。 三行 研究工作如下：首先，进行实验， 视区V_1、V_2和V_3的视差选择神经元的反应。 V3A对立体图形和动态随机点立体图的不同 亮度对比度 观看时立体感下降或丢失 等亮度立体视觉：立体视觉反应的变化 低亮度对比度刺激的猴神经元将是一个强的 表明这些神经元在立体视觉中的直接作用。 此外，这些实验的结果将提供有关 哪个解剖生理视觉子系统（大细胞或小细胞） 具有立体特性的神经元是一部分。 相关系列 实验将被设计来研究潜在的机制， 皮质神经元对随机点立体图的反应，即 提供基板的机构，用于正确匹配 在两个眼睛中的图像的相应元素，人类的任务， 实验对象表现得毫不费力且最准确。 最后，我将尝试 评估注意力和动机对神经系统的影响， 不同皮层区域的深度神经元的反应。 基本方略 这些实验将是训练猴子参加非常 激活所研究的皮质神经元的刺激，并识别 神经元的反应差异时，刺激是或不是 与猴子的行为相关性

This program of research aims at an understanding of the operational mechanisms in the cerebral cortex of primates which underlie stereoscopic depth perception. Experiments will be conducted in alert rhesus monkeys behaviorally trained to perform repeatedly a visual task, while single neuron activity will be recorded with one or more microelectrodes from striate and prestriate cortex. Stimuli will be presented stereoscopically on two color displays separately seen by the left and right eyes, and generated with a high-speed graphics system. The position of one (or both) eyes will be monitored continuously in order to control the monkey's direction of gaze. The principal objective is to obtain experimental evidence for or against the hypothesis that disparity-selective responses of cortical visual neurons are directly linked to stereoscopic depth perception, and to ascertain the significance of the different types of the neural disparity selectivity in the stereoscopic process. Three lines of investigation will be followed: First, experiments will be done to assess the responses of disparity selective neurons in visual areas V1, V2 and V3- V3A to solid figure and dynamic random-dot stereograms of different luminance contrast. Stereopsis is degraded or lost when viewing isoluminant stereopatterns: changes in the responses of stereoscopic neurons of monkey with stimuli of low luminance contrast would be a strong indication in favor of a direct role of these neurons in stereopsis. Moreover, the results of these experiments would provide information about which anatomo-physiological visual subsystem (magno- or parvo-cellular) neurons with stero properties are part. An associated series of experiments will be designed to investigate the mechanisms underlying the responses of cortical neurons to random-dot stereograms, that is of the mechanisms providing the substrate for the correct matching of corresponding elements of the images in the two eyes, a task that human subjects perform effortlessly and most accurately. Finally, I will attempt to assess the influences of attention and motivation on the neural responses of depth neurons in different cortical areas. The basic strategy of thee experiments will be to train the monkey to attend to the very stimulus that activates the cortical neuron under study, and to identify differences in the neuron's responses when that stimulus is or is not of behavioral relevance to the monkey.