Localization Performance of Multiple Vibrotactile Cues on Both Arms.

To present information using vibrotactile stimuli in wearable devices, it is fundamental to understand human performance of localizing vibrotactile cues across the skin surface. In this paper, we studied human ability to identify locations of multiple vibrotactile cues activated simultaneously on both arms. Two haptic bands were mounted in proximity to the elbow and shoulder joints on each arm, and two vibrotactile motors were mounted on each band to provide vibration cues to the dorsal and palmar side of the arm. The localization performance under four conditions were compared, with the number of the simultaneously activated cues varying from one to four in each condition. Experimental results illustrate that the rate of correct localization decreases linearly with the increase in the number of activated cues. It was 27.8 percent for three activated cues, and became even lower for four activated cues. An analysis of the correct rate and error patterns show that the layout of vibrotactile cues can have significant effects on the localization performance of multiple vibrotactile cues. These findings might provide guidelines for using vibrotactile cues to guide the simultaneous motion of multiple joints on both arms.