Wüst R, Kappers A M, Koenderink J J
Utrecht Biophysics Research Institute, Rijksuniversiteit Utrecht, The Netherlands.
Percept Psychophys. 1992 Jun;51(6):569-79. doi: 10.3758/bf03211654.
Subjects were asked to match the speeds of two moving random-dot patterns seen through circular apertures. The speed of one pattern that moved horizontally toward the right of a computer screen changed continuously. The speed of this pattern represented the target. It was to be matched with the speed of the second pattern, which moved in the opposite direction. The subject controlled the speed of the second pattern by means of an isometric joystick. The distance between the apertures on the screen as well as the subject's distance from the screen served as experimental parameters. In this way, the effects of both spatial and temporal transients of pattern speed on human tracking performance were studied. To avoid anticipation by the subject, the amplitude and the frequency of the target pattern speed changed pseudorandomly. The accuracy with which the subject performed the matching task was influenced by the mean pattern speed and the parameters of the visual field. Within lower velocity ranges, the subject's sensitivity to the instantaneous speed differences varied according to Weber's law. The cross-correlation of the velocity time courses decreased when the mean speed of the target pattern was increased. Two stimulus parameters had a strong influence on the modulation of the correlation value: (1) the angular size of the stimulus on the retina and (2) the retinal eccentricity of the stimulus.
受试者被要求匹配通过圆形孔径看到的两个移动随机点图案的速度。其中一个图案在电脑屏幕上水平向右移动，其速度不断变化。这个图案的速度代表目标，要与向相反方向移动的第二个图案的速度相匹配。受试者通过等距操纵杆控制第二个图案的速度。屏幕上孔径之间的距离以及受试者与屏幕的距离作为实验参数。通过这种方式，研究了图案速度的空间和时间瞬变对人类跟踪性能的影响。为了避免受试者产生预期，目标图案速度的幅度和频率伪随机变化。受试者执行匹配任务的准确性受平均图案速度和视野参数的影响。在较低速度范围内，受试者对瞬时速度差异的敏感度根据韦伯定律而变化。当目标图案的平均速度增加时，速度时间历程的互相关性降低。两个刺激参数对相关值的调制有很大影响：（1）视网膜上刺激的角大小和（2）刺激的视网膜偏心度。
