Vibratory Feedback on the Forearm is Less Preferred but Similarly Effective as Fingertips for Fine Motor Task in...

Extended reality (XR) systems leverage multisensory feedback to convey environmental states to the user. Haptic feedback can improve immersivity and performance when operating in XR environments, but it is rarely used in commercial systems. We sought to investigate the usability of haptic feedback displaced to the forearm in a challenging XR manipulation task, in which participants grasped and transported breakable virtual eggs from one side of a virtual table to another. Several vibrotactile feedback conditions were tested, including variations in location (i.e., fingertips vs. forearm) and channel count. We found that introducing haptic feedback improved participants' accuracy, but most performed the task more slowly. There was not a significant difference in success rate or trial completion time between vibration locations. Increasing fingertip channel count improved success rate by 51% without hindering trial completion time. When participants were asked for their preferred feedback modality, 69% preferred fingertip vibration, while 31% preferred forearm vibration. In conditions with haptic feedback, 11 of the 16 participants performed the task more slowly when they received vibration in their preferred location. Overall, these results provide promise for haptic feedback delivery that is spatially removed from the hand and fingers in XR systems.