Function of fixational instability during natural viewing

自然观看过程中注视不稳定性的作用

• 批准号: 7486810
• 负责人: MICHELE RUCCI
• 金额: $ 31.85万
• 依托单位: BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7486810
• 关键词: Address; Affect; Age; Albinism; Brain; Characteristics; Chronic; Clinical; Comprehension; Computer Simulation; Condition; Coupled; Detection; Discrimination; Dyslexia; Employee Strikes; Experimental Models; Exposure to; Eye; Eye Movements; Frequencies; Grant; Image; Impairment; Individual; Joints; Judgment; Laboratories; Lateral Geniculate Body; Lead; Link; Maintenance; Modeling; Motion; Movement; Neurons; Noise; Numbers; Ocular Fixation; Pattern; Perception; Performance; Photic Stimulation; Pliability; Population; Production; Psychometrics; Psychophysics; Psychophysiology; Relative (related person); Research; Research Project Grants; Retina; Retinal; Role; Saccades; Signal Transduction; Simulate; Staging; Stimulus; Structure; Study models; System; United States National Institutes of Health; Ursidae Family; Vision; Vision Disorders; Vision research; Visual; Visual Perception; Visual impairment; Visual system structure; area striata; base; computer studies; experience; experimental analysis; gaze; human subject; luminance; oculomotor; prevent; programs; relating to nervous system; research study; response; sample fixation; simulation; spatiotemporal; statistics; vision development; visual information

DESCRIPTION (provided by applicant): During visual fixation, small eye movements of which we are usually not aware, prevent the maintenance of a steady direction of gaze. It is known that images tend to fade when retinal motion is eliminated in the laboratory. However, it has long been debated whether, during natural viewing, fixational eye movements do more than prevent the visual scene from fading. The results of experiments conducted during a previous Grant for Pilot Research indicate that fixational eye movements contribute to the perception of fine spatial detail, as predicted by our models and as speculated for more than a century. This proposal describes a program of research, which combines psychophysical experiments with human subjects, computational modeling of neurons in the early visual system, and statistical analysis of the visual input the retina to study the contributions of fixational eye movements in pattern vision. Psychophysical experiments will examine the detection and discrimination of stimuli presented, with and without retinal image motion, during the brief intersaccadic periods of natural visual fixation. To overcome the technical limitations of previous studies on retinal stabilization, experiments will rely on a new system of gaze-contingent display, which enables rigorous comparison between the two conditions of normal retinal motion and retinal stabilization. This system enables us to (a) selectively stabilize the stimulus after a saccade, a condition that preserves the normal fixational motion of the eye, (b) randomly alternate trials with and without retinal image motion, and (c) assess the accuracy of retinal stabilization independently of the subject's own judgment. Computational studies will examine the visual input signals experienced by subjects in the experiments, and simulate the responses of neurons in the retina, the lateral geniculate nucleus, and the striate cortex. For every experimental trial, a simulation will replicate neuronal activity during the sequence of eye movements performed by the subject. Subject performance and information about the stimulus transmitted by neuronal responses will be compared on a trial-by-trial basis. 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 treatment of the visual impairments commonly associated with such conditions.

描述（由申请人提供）：在视觉固定期间，我们通常不知道的小眼动，以防止保持稳定的凝视方向。众所周知，当实验室中消除视网膜运动时，图像往往会消失。但是，长期以来一直在争论，在自然观看期间，固定的眼动不仅仅是防止视觉场景褪色。正如我们的模型所预测的那样，在先前的试点研究赠款期间进行的实验结果表明，固定的眼球运动有助于对精细的空间细节的感知，并推测一个多世纪以来。该建议描述了一项研究计划，该计划将心理物理实验与人类受试者，早期视觉系统中神经元的计算建模以及视觉输入的统计分析相结合，视网膜研究了固定眼运动在模式视觉中的贡献。心理物理实验将在短暂的自然视觉固定时期中，检查和没有视网膜图像运动的刺激的检测和区分。为了克服先前关于视网膜稳定的研究的技术局限性，实验将依靠一个新的凝视诱导显示系统，这可以在正常的视网膜运动和视网膜稳定的两个条件之间进行严格的比较。该系统使我们能够（a）在扫视后选择性稳定刺激，这种条件保留了眼睛的正常固定运动，（b）随机进行有或没有视网膜图像运动的随机交替试验，以及（c）评估视网膜的准确性独立于主体自己的判断而稳定。计算研究将检查实验中受试者所经历的视觉输入信号，并模拟视网膜中神经元的反应，侧向基因核和侧条皮层。对于每个实验试验，模拟将在受试者执行的眼睛运动序列中复制神经元活性。将通过试用的基础比较有关神经元反应传递的刺激的受试者性能和信息。许多视觉障碍表现出异常的固定眼动运动。除了促进我们对视觉感知的基本理解之外，对固定不稳定性的功能含义的理解可能会导致对通常与此类条件相关的视觉障碍的治疗。