Packer O, Williams D R
Center for Visual Science, University of Rochester, NY 14627.
Vision Res. 1992 Oct;32(10):1931-9. doi: 10.1016/0042-6989(92)90052-k.
A complete description of the loss of contrast sensitivity at high spatial frequencies requires an estimate of the role of eye movements, which could blur fine detail. We describe a new technique to isolate their effect. Observers viewed either a 100 c/deg interference fringe, which the cone mosaic aliased to a low frequency zebra stripe, or an artificial zebra stripe. The real and artificial zebra stripes have similar spatial patterns, but differ in the temporal modulation produced by eye movements. Contrast threshold was measured as a function of duration for both stimuli flashed in the dark. The ratio of the contrast thresholds for the real and artificial zebra stripes with long durations, when eye movements could have a differential effect, is always within a factor of two or so of the ratio for 1 msec flashes, when eye movements are eliminated. These results support the view that eye movements are only a minor source of image degradation even at very high spatial frequencies, and provide no support for the view that they improve high resolution tasks.
要完整描述高空间频率下对比度敏感度的损失，需要估计眼动的作用，因为眼动可能会模糊精细细节。我们描述了一种新的技术来分离其影响。观察者观看100周/度的干涉条纹（视锥细胞镶嵌将其混叠为低频斑马条纹）或人工斑马条纹。真实和人工斑马条纹具有相似的空间模式，但在眼动产生的时间调制方面有所不同。在黑暗中呈现两种刺激时，测量对比度阈值作为持续时间的函数。当眼动可能产生不同影响时，长时间呈现的真实和人工斑马条纹的对比度阈值之比，与消除眼动的1毫秒闪光的对比度阈值之比相比，始终在两倍左右的范围内。这些结果支持这样一种观点，即即使在非常高的空间频率下，眼动也只是图像退化的一个次要来源，并且不支持眼动能改善高分辨率任务的观点。
