Localization of Vibrotactile Stimuli on the Face

TL;DR

This study investigates the localization accuracy of vibrotactile stimuli on the face, aiming to inform the development of facial haptic feedback devices for assistive applications.

Contribution

It provides the first characterization of vibrotactile localization acuity on the face using off-the-shelf motors and experimental methods adapted from other skin regions.

Findings

Participants demonstrated measurable localization accuracy on the cheek.

Results suggest potential for facial vibrotactile feedback in assistive technology.

Data informs design of compact facial haptic devices.

Abstract

The face remains relatively unexplored as a target region for haptic feedback, despite providing a considerable surface area consisting of highly sensitive skin. There are promising applications for facial haptic feedback, especially in cases of severe upper limb loss or spinal cord injury, where the face is typically less impacted than other body parts. Moreover, the neural representation of the face is adjacent to that of the hand, and phantom maps have been discovered between the fingertips and the cheeks. However, there is a dearth of compact devices for facial haptic feedback, and vibrotactile stimulation, a common modality of haptic feedback, has not been characterized for localization acuity on the face. We performed a localization experiment on the cheek, with an arrangement of off-the-shelf coin vibration motors. The study follows the methods of prior work studying other skin regions, in which participants attempt to identify the sites of discrete vibrotactile stimuli. We intend for our results to inform the future development of systems using vibrotactile feedback to convey information via the face.