ASSESSMENT OF VISUAL FUNCTION USING LUMINANCE NOISE

视觉处理的效率低下可以分为两大类 类别：不可靠的“噪音”的神经系统和 系统误差或“失真”。 拟议研究的目标是 精神病理学特征的视觉缺陷的人类观察者， 固有噪声和系统误差。 本研究结果 有可能定位视觉问题的根源， 有用的诊断指标，并了解的根本原因， 视觉缺陷 将视觉检测的低效率划分为 这两个分量可以通过测量对比度来实现 敏感性（及其变化率）在各种水平的存在下， 视觉噪声 该技术具有以下优点， 常规对比敏感度测量：1）高对比度检测 噪声水平可以有效地绕过光学器件， 性能主要取决于后续产品的质量 神经机制，不管它的噪音。 2)比较高 低噪声性能的噪声性能导致 “噪音”3）高水平的噪音允许研究高对比度 视觉与已应用于低对比度的方法相同 视野 4)人的表现可以用绝对尺度来衡量。 的 一种称为“效率”的衡量标准，指定了可用资源的比例， 观察者使用的统计信息。 为了评估 利用这一程序，研究将限于两类 患者：主要为视神经介质混浊的患者，以及 神经炎 认为第一类主要表现为系统性 视觉误差，而第二个可能会显示增加的噪音， 信息传输

Inefficiency of visual processing may be partitioned into two broad categories: unreliability of "noisiness" of the nervous system and systematic error or "distortion". The goal of the proposed research is to psychophysically characterize the visual deficit of human observers in terms of intrinsic noise and systematic error. Results from this study have the potential to localize the source of a visual problem, to produce useful diagnostic indicies and to understand the underlying causes of visual deficits. The partitioning of inefficiency of visual detection into these two components may be accomplished by the measurement of contrast sensitivity (and its rate of change) in the presence of various levels of visual noise. This technique has the following advantages over conventional contrast sensitivity measures: 1) Contrast detection in high levels of noise can effectively by-pass the optics, yielding a measure of performance which is primarily dependent on the quality of the succeeding neural machinery irrespective of its noisiness. 2) Comparison of high noise performance with low noise performance leads to an index of "noisiness" 3) High levels of noise permit the study of high contrast vision with the same methods which have been applied to low contrast vision. 4) Human performance can be measured on an absolute scale. The measure called "efficiency", specifies the fraction of the available statistical information an observer is using. In order to assess the utility of this procedure, the study will restrict itself to two classes of patients: those with primarily optic media opacities, and those with optic neuritis. It is believed that the first class may show mainly systematic errors of vision, whereas the second may show increased noisiness of information transmission.