在稳定和正常观看条件下的速度辨别

Speed discrimination under stabilized and normal viewing conditions.

作者信息

Heidenreich S M, Turano K A

机构信息

Psychology Department, University of San Francisco, CA 94117, USA.

出版信息

Vision Res. 1996 Jun;36(12):1819-25. doi: 10.1016/0042-6989(95)00270-7.

DOI:10.1016/0042-6989(95)00270-7

PMID:8759450

Abstract

To determine whether speed discrimination improves when the retinal image is stabilized against the effects of eye movements, thresholds were measured under stabilized and normal viewing conditions. In the normal viewing conditions, eye movements were recorded and used to estimate retinal-image speeds. Stimulus reference speed for sinusoidal gratings varied from 0.5 to 8.0 deg/sec. Results showed that speed discrimination thresholds, expressed as Weber ratios, decreased with increasing stimulus speed for both the normal and stabilized viewing conditions. Stabilized viewing thresholds were higher than normal viewing thresholds only at the slowest stimulus reference speed. However, when speed discrimination thresholds were expressed as a function of the estimated retinal speed, there was no difference in thresholds for the stabilized and normal viewing conditions. A retinal-image model, whereby speed discrimination depends on retinal-image motion, explains the results.

摘要

为了确定当视网膜图像相对于眼球运动的影响稳定时，速度辨别能力是否会提高，我们在稳定和正常观看条件下测量了阈值。在正常观看条件下，记录眼球运动并用于估计视网膜图像速度。正弦光栅的刺激参考速度在0.5至8.0度/秒之间变化。结果表明，以韦伯比率表示的速度辨别阈值，在正常和稳定观看条件下均随刺激速度的增加而降低。仅在最慢的刺激参考速度下，稳定观看阈值高于正常观看阈值。然而，当速度辨别阈值表示为估计视网膜速度的函数时，稳定和正常观看条件下的阈值没有差异。一个视网膜图像模型，即速度辨别取决于视网膜图像运动，可以解释这些结果。