Comparison between four assignments of slip-perception and stroke-reproduction task to dominant/nondominant hand

Abstract

The objective of this study is to compare four kinds of hand assignments of slip-perception and stroke-reproduction task to dominant/nondominant hand for right handed persons based on a device that can present slippages to users via their fingerpad skin. The device is called an “active-wheel-based finger-tactile interface (AWB-FTI)” in this paper. It is an interface that embodies an active wheel being rotatable in any directions, with any speeds, and with any time durations. The movements result in slippage stimuli on users’ fingerpad skin. Then, users are supposed to recognize the slippages as line-segments in a mental image. The reproduction of the recognized line-segments as the hand strokes with proprioceptive sensations is effective for storing the recognition in users’ memory. The performance of the device is measured by a pair of tasks composed of the slip-perception task and the stroke-reproduction task. Each of the pair of tasks should be assigned to either dominant hand or nondominant one. That is, four hand assignments are defined for the perception and the reproduction: the hand used for perception and that for the reproduction are “Dominant×ipsilateral,” “Dominant×contralateral,” “Nondominant×ipsilateral,” and “Nondominant×contralateral.” The reproduction errors of the four hand assignments were measured through a comparative psychophysical experiment with the slip-perception and stroke-reproduction task. As a result, we found the following characteristics: (1) as for the slippage-speeds and -angles, the nondominant hand was better than the dominant one from the viewpoints of both random and systematic errors in the perceptual hand, while either nondominant or dominant hand showed no significant difference in the reproductive hand, (2) as for the slippage time-durations, the “Dominant×contralateral” was worst in the four hand assignments from the viewpoint of random errors, and the “Nondominant×contralateral” was best from the viewpoint of systematic errors.