Function of Fixational Instability During Natural Viewing

描述(申请人提供)：我们的眼睛永远不会休息。我们通常没有意识到微观的眼球运动不断地抖动凝视的位置，即使在关注场景中的一个点时也是如此。众所周知，当视网膜图像运动在实验室中被消除时，视觉感知往往会褪色。然而，也有人假设，在自然观看的过程中，凝视的眼球运动不仅仅是防止视觉场景褪色。我们最近由美国国立卫生研究院资助的研究的几个发现，包括在观看自然场景时冲击视网膜的时间能量的空间均衡，表明眼睛的注视运动在视觉信息处理中发挥着重要作用。基于我们最近的结果，这个项目解决了三个基本问题：(目标1)空间信息是如何在凝视眼球运动引起的亮度调制中编码的？(目标2)视觉系统如何提取和解释这些信息？(目标3)输入能量的时空重新分配是否灵活，以便可以根据任务进行调整？为了将凝视眼球运动的知觉影响与它们对视觉信息神经编码的影响联系起来，这个项目整合了人类的视觉心理物理学、视网膜输入分析和神经建模。心理物理实验将依赖于一种灵活、复杂的凝视显示系统，我们已经开发并进行了广泛的测试，以测试在受控视网膜图像运动下的检测和辨别性能。统计、计算和建模研究将检查受试者在高敏感度视觉任务中经历的视觉输入信号，并模拟视网膜和外侧膝状体神经元的反应。这些研究有可能迫使我们对视网膜编码的理解发生根本性转变，用一种新的观点取代纯粹感觉加工阶段的传统观点，在这种观点中，感知和行为的联系比之前认为的要密切得多。此外，一些视觉障碍表现出异常的凝视眼球运动。除了促进我们对视觉感知的基本理解外，对注视不稳定的功能暗示的理解可能会导致对通常与这种情况相关的视觉损伤的新的治疗方法。 与公共健康相关：在自然观看期间，人类不断地进行微观的眼球运动。这些运动在各种病理情况下都是异常的，视觉能力下降。通过研究微观眼球运动的视觉功能，该项目将促进对正常人类视觉作为一个完整的感觉运动过程的理解，并可能为通常与此类疾病相关的视觉障碍开辟新的治疗方法。

DESCRIPTION (provided by applicant): Our eyes are never at rest. We are normally not aware that microscopic eye movements continually jitter the location of gaze, even when attending to a single point in the scene. It is known that visual percepts tend to fade when retina image motion is eliminated in the laboratory. However, it has also been hypothesized that, during natural viewing, fixational eye movements do more than prevent the visual scene from fading. Several findings from our recent NIH-funded research, including a spatial equalization of the temporal energy impinging on the retina during viewing of natural scenes, suggest that the fixational motion of the eye plays an important role in the processing of visual information. Building upon our recent results, this project addresses three fundamental questions: (Aim 1) How is spatial information encoded in the modulations of luminance resulting from fixational eye movements? (Aim 2) How is this information extracted and interpreted by the visual system? (Aim 3) Is the spatiotemporal redistribution of input energy flexible, so that it can be adjusted according to the task? To link the perceptual influences of fixational eye movements to their effect on the neural coding of visual information, this project integrates visual psychophysics in humans, analysis of retinal input, and neural modeling. Psychophysical experiments will rely on a flexible, sophisticated system for gaze-contingent display, which we have developed and extensively tested, to examine detection and discrimination performance under controlled retinal image motion. Statistical, computational, and modeling studies will examine the visual input signals experienced by subjects during high- acuity visual tasks and simulate the responses of neurons in the retina and lateral geniculate nucleus. These studies have the potential to force a radical shift in our understanding of retinal coding, replacing the traditional view of a purely sensory processing stage with a new view, in which perception and behavior are much more intimately tied than previously thought. Furthermore, a number of visual disorders manifest abnormal fixational eye movements. In addition to advancing our basic understanding of visual perception, a comprehension of the functional implications of fixational instability may lead to new treatment approaches for the visual impairments commonly associated with such conditions. PUBLIC HEALTH RELEVANCE: During natural viewing, humans continually perform microscopic eye movements. These movements are abnormal in various pathological conditions with reduced visual capabilities. By investigating the visual functions of microscopic eye movements, this project will advance the understanding of normal human vision as an integrated sensorimotor process and may open the way to new treatment approaches for the visual impairments commonly associated with such conditions.