CONSTRAINTS ON VISION AT LOW LIGHT LEVELS

我们看到空间模式的能力在很大程度上取决于 普遍的照明。 本研究的长期目标有两个： 考虑空间阈值随光照水平的变化，以及 描述在昏暗的环境中对阈上模式的感知， 照明。 实验提出区分光学从 神经约束，并估计对空间视觉的限制 通过神经采样、过滤和各种光照水平下的噪声。 的 本研究的具体目的是：1）量化光学效应 在昏暗的光线下失去空间视觉的散焦，2）检查 光栅可见度如何受到 3）区分神经空间滤波和 弱光照下的采样约束，4）调查 视觉系统在不同光照下的空间采样特性 水平，以及5）表征阈上移动的出现 和在昏暗照明下的静止图案。 测量将 在成年人的观察者，使用刺激和客观的 优化视觉表现的心理物理技术。 本研究 将提供一套全面的敏锐度和对比敏感度数据 对于正常的观察者，这将有助于建模和临床 应用.

Our ability to see spatial patterns depends, to a great extent, on the prevailing illumination. The long term goals of this study are twofold: to account for the changes in spatial thresholds with light level, and to characterize the perception of suprathreshold patterns under dim illumination. Experiments are proposed to differentiate optical from neural constraints and to estimate the limits imposed on spatial vision by neural sampling, filtering and noise at various light levels. The specific aims of this study are: 1) to quantify the effect of optical defocus in the loss of spatial vision at dim light levels, 2) to examine how grating visibility is influenced by the adaptation state of the surrounding retina, 3) to differentiate neural spatial filtering and sampling constraints under dim illumination, 4) to investigate the spatial sampling properties of the visual system at various light levels, and 5) to characterize the appearance of suprathreshold moving and stationary patterns under dim illumination. Measurements will be made on adult human observers, using stimuli and objective psychophysical techniques that optimize visual performance. This study will provide a comprehensive set of acuity and contrast sensitivity data for normal observers that will be useful in modeling and clinical applications.