Function of Fixational Instability During Natural Viewing

项目总结 人类没有意识到他们的眼睛总是在运动。即使在处理单点问题时，fixational 眼球运动(Fem)不断地改变视网膜上的刺激，使之立即可见。 运动源于场景中的物体，而不是动眼活动。现在很清楚，有限元方法是 对视觉敏感度、fine图案视力和敏锐度至关重要。此外，相当多的证据部分地 来自我们NIH资助的研究表明，这种行为体现了一种感觉运动策略，通过这种策略，视觉 系统在时间域中处理空间信息。虽然人们已经了解了很多关于单核细胞的事情- 由于有限元的局部功能，人们对其对双目视觉的影响知之甚少。眼球漂移--无休止 眼跳间运动--两只眼睛有很大的不同。视觉系统是如何连续组合的 改变来自独立抖动的眼睛的输入？在这里，我们集中于三维空间表示的有限元结果。 句子，特别是它们在立体视觉中的作用(目标1)，它们的解码机制(fi2)，以及它们的双眼 对照(目标3)。研究策略包括评估有限元对双目视觉输入的影响和对双目视觉输入的影响。 由此产生的对神经编码、感知和控制的影响。我们的驾驶假说是 在亮度的单目处理中出现的主动空时编码策略也适用于PRO 在视觉流的后期阶段获得双目视觉派生的特征。因为这一理论产生了与直觉相反的 假设，每个目标都建立在为拟议的实验奠定基础的支持性准备研究的基础上。 目标1建立在一个令人惊讶的观察基础上，即当fi视差调制被 从视觉fl中选择性地消除，即使在存在其他正常的亮度调制时也是如此 视网膜。我们将探讨这种损害的原因，并阐明有限元的贡献。目标2侧重于 解释fi交叉视觉flow的机制。与传统的假设相反，我们的初步假设- 没有证据表明，视觉系统可以接触到视网膜外的眼球漂移知识，并利用它来 以高时空分辨率推断空间关系。目标3在动眼神经的背景下检验这些想法 控制力。我们提供了fi第一次对自然界中的无头双目有限元进行全面的高分辨率测量。 真实世界的任务，并测试眼球漂移被主动控制的假设，以编码与任务相关的特征 (例如，差异、空间对比度等)。实验依赖于(A)双目测量的组合 以及(B)高度的fl分辨率，双目同步，凝视-- 视情况控制视网膜刺激，这是我们最新的仪器发展使之成为可能的方法。 所有实验都有理论依据，所有假设都有新的初步数据支持。他们是，到 我们的知识是全新的，对其中任何一种的理解都将具有广泛的意义 视觉系统的功能原理，感知的计算机制，可能的动眼 对神经眼科疾病的贡献，以及康复策略和假体的开发。

PROJECT SUMMARY Humans are not aware that their eyes are always in motion. Even when attending to a single point, fixational eye movements (FEM) continually shift the stimulus on the retina in ways that would be immediately visible had the motion originated from objects in the scene rather than oculomotor activity. It is now clear that FEM are vital for visual sensitivity, fine pattern vision, and acuity. Furthermore, a considerable body of evidence, in part from our NIH-funded research, indicates that this behavior embodies a sensorimotor strategy by which the visual system processes spatial information in the temporal domain. While much has been learned about the monoc- ular functions of FEM, little is known about their consequences for binocular vision. Ocular drifts—the incessant inter-saccadic movements—differ considerably in the two eyes. How does the visual system combine continually changing inputs from independently jittering eyes? Here we focus on FEM consequences for 3D spatial repre- sentations, specifically their role in stereopsis (Aim 1), their decoding mechanisms (Aim 2), and their binocular control (Aim 3). The research strategy consists of assessing FEM effects on the binocular visual input and ex- amining the resulting implications for neural coding, perception, and control. Our driving hypothesis is that the active space-time encoding strategy that emerged in the monocular processing of luminance also applies to pro- cessing binocularly-derived features at later stages of the visual stream. Since this theory yields counter-intuitive hypotheses, each aim builds on a supporting preparatory study that sets the stage for the proposed experiments. Aim 1 builds on the surprising observation that stereopsis is impaired when fixational disparity modulations are selectively eliminated from the visual flow, even in the presence of otherwise normal luminance modulations on the retina. We will explore the causes for this impairment and elucidate FEM contributions. Aim 2 focuses on the mechanisms by which the fixational visual flow is interpreted. Contrary to traditional assumptions, our prelimi- nary evidence indicates that the visual system has access to extraretinal knowledge of ocular drift and uses it to infer spatial relations at high spatiotemporal resolution. Aim 3 examines these ideas in the context of oculomotor control. We provide the first comprehensive high-resolution measurements of head-free binocular FEM in natural real-world tasks and test the hypothesis that eye drifts are actively controlled to encode task-relevant features (e.g., disparity, spatial contrast, etc.). The experiments rely on the combination of (a) binocular measurements of human eye movements with unprecedented accuracy; and (b) highly flexible, binocularly synchronized, gaze- contingent control of retinal stimulation, an approach made possible by our recent instrumentation developments. All experiments are theoretically grounded and all hypotheses supported by new preliminary data. They are, to our knowledge, entirely novel, and confirmation of any of them will have broad implications for understanding the functional principles of the visual system, the computational mechanisms of perception, possible oculomotor contributions to neuro-ophthalmologic disorders, and the development of rehabilitative strategies and prostheses.