VISUAL ATTENTIVE PROCESSES

一个人可以进行的最简单的认知行为之一就是有选择地参加 并凝视视觉场景的一部分。在专心注视的过程中， 视野的图像在视网膜上不是一动不动的，而是主体 到微小的运动，根据头部的程度有很大的变化 和身体支撑。然而，这些微小的运动并没有明显地影响 感性的表现。视觉神经生理学中的一个基本问题 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。这个 这项研究计划的广泛目标是阐明 作为人类能力基础的注意过程的神经机制 将基本视觉特征分离并分组到图形中，并 物体感知的背景组合。在这篇文章中提出的研究 应用程序解决了这个更广泛的计划的一个特定问题，即是否 或者不是初级视觉皮质通过动态的 由视网膜图像运动驱动的位置补偿过程，如果是， 在什么情况下。这个问题将分四个阶段进行调查， 通过检查纹状体内单个神经元的活动，提出以下问题 当受试者执行视觉注意任务时，视觉皮质。 第一，单目位置补偿。专心致志的注视有效果吗？ 在动态空间稳定的纹状体之间的关系 大脑皮层感受野及其与外部世界的映射？ 第二，补偿--必要条件。视觉条件是什么？ 单眼位置补偿的必要性和充分性？ 第三，立体视觉中的双目补偿。是立体敏感的条纹 皮质神经元对眼睛位置的不同变化不敏感 发生在专心注视的过程中？ 第四，视在运动中的补偿和短程过程。会吗？ 低速运动刺激的位置补偿 与短程过程相关的预测性空间内插 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?