VISUAL ATTENTIVE PROCESSES

一个人能做的最简单的认知行为之一就是有选择地参加 并且固定视觉场景的一部分。 在注意力集中时， 视野的图像在视网膜上不是静止的，而是受影响的。 到小的动作，变化很大，取决于头部的程度， 身体支撑。 然而，这些小动作并不影响 知觉表现 视觉神经生理学的一个基本问题 视觉系统是如何考虑这种位置不稳定性的 在其处理视觉场景的基本特征期间。 的 这项研究计划的广泛目标是阐明中央 注意过程的神经机制是人类能力的基础 将基本视觉特征分离和分组到图形中， 物体感知的背景组合。 本报告中提出的研究 申请解决这个更广泛的计划的一个具体问题，即是否 或不是初级视觉皮层解决了不稳定的问题， 由视网膜图像运动驱动的位置补偿过程，并且如果是， 在什么条件下。 将分四个阶段调查这一问题， 下面提出的问题，通过检查单个神经元活动的纹状体 当受试者执行视觉注意任务时，视觉皮层。 第一，单眼位置补偿。 注意力集中是否会导致 在一个动态的空间稳定的关系， 皮层感受野及其与外部世界的映射 第二，补偿--必要条件。 什么样的视觉条件 必要和充分的单目位置补偿？ 第三，立体视觉中的双眼补偿。 是立体敏感的条纹 对眼睛位置的不同变化不敏感的皮层神经元 发生在注意力集中的时候 第四，视运动中的补偿和短程过程。 并 对低速运动刺激的位置补偿是由 预测性空间内插相关的短期过程 动议？

One of the simplest cognitive acts one can perform is to attend selectively and fixate a portion of the visual scene. During attentive fixation, the image of the visual field is not motionless on the retina, but is subject to small movements that vary considerably depending upon the degree of head and body support. However, these small movements do not appreciably affect perceptual performance. A fundamental question in visual neurophysiology is how the visual system takes this positional instability into account during its processing of the elemental features of the visual scene. The broad objectives of this research program are to elucidate the central neural mechanisms of attentive processes that underlie the human's capacity to segregate and group elemental visual features into the figure and background combinations of object perception. The studies proposed in this application address a specific issue of this broader program,namely whether or not primary visual cortex solves the instability problem by a dynamic positional compensation process driven by retinal image motion, and if so, under what conditions. This issue will be investigated in four stages, posed below as questions, by examining single neuron activity in striate visual cortex while a subject performs a visual attentive task. First, Monocular Positional Compensation. Does attentive fixation result in a dynamic spatial stabilization of the relationship between striate cortical receptive fields and their mapping to the external world? Second, Compensation - Necessary Conditions. What visual conditions are necessary and sufficient for monocular positional compensation? Third, Binocular Compensation in Stereopsis.. Are stereosensitive striate cortical neurons insensitive to the disparate changes in eye position occurring during attentive fixation? Fourth, Compensation and Short Range Processes in Apparent Motion. Does positional compensation for low speed moving stimuli result from a predictive spatial interpolation related to short range processes of motion?