Large systematic deviations in the haptic perception of parallellity

Abstract

There is increasing evidence that haptic space is not veridical. One of the first to report on this phenomenon was Blumenfeld (1937). Recently, Kappers and Koenderink (1998) showed that what subjects haptically perceive as parallel often deviates largely from what is actually physically parallel. These deviations are not random but show distinctive patterns. This study is an extension of their experiment: (1) The possible positions of the stimuli cover a much larger area, so that the distances between the stimuli can also be much larger. (2) Experiments are done both unimanually (right and left hand) and bimanually.