Enhancement of the Force Perception on the Wrist under the Hanger Reflex by Presenting Vibration

Abstract

The Hanger Reflex is a phenomenon that a head rotates involuntarily when the head is fastened with a wire hanger. This phenomenon is also observed on the wrist, and is expected to apply for small and simple haptic feedback device. However, the poor responsiveness and large actuators are still left as issues. In the meantime, we discovered a phenomenon that the perceptual force from the hanger reflex is enhanced when the vibration is presented to the wrist. If we can control this simple and strong perceptual illusion, we can cope issues still left and realize the small and simple haptic device. Therefore, in order to apply this phenomenon to the haptic device, this paper reports details about this phenomenon and the effect of the frequencies and amplitudes of the vibration. As results of the experiments, we observed that the low frequency (50-100Hz) vibrations efficiently enhanced the perceptual force. Also, we observed that the participants perceived stronger perceptual force if the vibration of a greater amplitude was presented. These results suggest that the enhancement of the perceptual force is controllable and can apply to the haptic device.