McKee S P, Welch L
J Opt Soc Am A. 1985 Feb;2(2):243-51. doi: 10.1364/josaa.2.000243.
Human observers can discriminate a 5% difference in velocity for a wide range of velocities. Using an apparent-motion stimulus, we demonstrated that velocity discrimination depends on the detection of small changes in asynchrony, changes of the order of 1 msec or less. The simplest component of an apparent-motion stimulus is a pair of spatially separate lines presented asynchronously. Generally the incremental asynchrony threshold for a single pair of lines is much too large to account for velocity discrimination. A sequence of five to eight asynchronously presented targets, equivalent to continuous motion viewed for a duration of 80-100 msec is required to reach asymptotic velocity discrimination. Our experiments rule out probability summation as the explanation for the enhanced temporal sensitivity observed with the sequential presentation of multiple asynchronous targets. Sequential recruitment, a descriptive term for this enhanced temporal sensitivity, depends on the summation of a velocity-specific signal within the physiological network responding to motion.
人类观察者能够在很宽的速度范围内辨别出5%的速度差异。使用表观运动刺激，我们证明速度辨别取决于对异步小变化的检测，变化量级为1毫秒或更小。表观运动刺激的最简单成分是一对异步呈现的空间上分开的线条。通常，一对线条的增量异步阈值太大，无法解释速度辨别。需要五到八个异步呈现的目标序列，相当于持续80 - 100毫秒观看的连续运动，才能达到渐近速度辨别。我们的实验排除了概率求和作为对多个异步目标顺序呈现时观察到的增强时间敏感性的解释。顺序募集是这种增强时间敏感性的一个描述性术语，它取决于在对运动做出反应的生理网络内速度特异性信号的总和。
