附加点作用下两点距离的触觉辨别

在被动触觉的距离知觉实验中，被试的右手保持不动，将各种三点型式的刺激轻轻接触食指腹侧或以一定速度通过其表面，要求被试判定外侧两点的直线距离并在一根量尺上复现出来．结果发现：（１）当刺激快速通过皮肤表面时，外侧两点距离表现出低估，其知觉距离显著地小于刺激静止或慢速运动条件下的知觉距离；（２）当中间附加点偏离外侧两点间想象连线较大时，外侧两点的知觉距离显著地小于中间附加点偏离较小时的知觉距离，偏离较大的中间附加点似乎将外侧两点拉近了，缩短了其知觉距离，出现知觉亲和现象．这种现象与刺激是否运动无关．

TACTILE DISCRIMINATION OF DISTANCE BETWEEN TWO POINTS UNDER EFFECT OF A NEARBY EXTRA POINT

In the experiment with three-point pattern(Lugvigh Target)the stimuli either touched upon or moved with fast or slow speed across the index finger pad which remained immoble. The experimental variables were distance between the two external points and degree of deviation of the middle point from the imaginary line between the external two. Six subjects were tested.Their task was to judge the distance between the external two and to reproduce it on a ruler. The basic findings were as follows: 1. The actual distance was always underestimated at fast speed, the apparent distance at fast speed was significantly shorter than that at slow speed and immobility. 2. The apparent distance at large deviation of the middle point was significantly shorter than that at small deviation regardless of stimulus presentation mode. The middle point at large deviation seemed to shrink the distance between the two external points. This phenomenon of perceptual affinity was discussed in ralation to the perceptual strategy.