Abstract: 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.

Key words: Tactile discrimination of distance, Ludvigh target, speed effect, perceptual affininty, perceptual strategy