Kortum P T, Geisler W S
Center for Vision and Image Sciences, University of Texas at Austin 78712, USA.
Vision Res. 1995 Jun;35(11):1595-609. doi: 10.1016/0042-6989(94)00206-2.
To examine how the mechanisms of light adaptation affect spatial pattern vision, contrast detection thresholds were measured for sinusoidal (increment-Gabor) probes on flashed backgrounds in the presence of steady adapting backgrounds. The thresholds for all spatial frequencies (1-12 c/deg), flashed-background intensities (dark to 4 log td) and adapting-background intensities (dark to 4 log td) were adequately described by a simple model consisting of a compressive nonlinearity (a modified Naka-Rushton function), a subtractive adaptation factor, and a multiplicative adaptation factor. For all five subjects the compressive nonlinearity was found to vary systematically with spatial frequency; for all but one subject, the subtractive and multiplicative factors were found to be relatively constant.
为了研究光适应机制如何影响空间模式视觉，在存在稳定适应背景的情况下，测量了在闪烁背景上正弦（增量-伽柏）探针的对比度检测阈值。所有空间频率（1-12周/度）、闪烁背景强度（从暗到4对数td）和适应背景强度（从暗到4对数td）的阈值都可以通过一个简单模型进行充分描述，该模型由一个压缩非线性（修正的中谷-拉什顿函数）、一个减法适应因子和一个乘法适应因子组成。对于所有五名受试者，发现压缩非线性随空间频率系统变化；除一名受试者外，发现减法和乘法因子相对恒定。
