Virtual Whiskers: Spatial Directional Guidance using Cheek Haptic Stimulation in a Virtual Environment

Spatial cues are an important element of navigating people in physical/virtual spaces. In terms of spatial navigation, integrating vision with other modalities, such as haptics, can guide users more effectively. Haptic cues are presented on the body parts that are sensitive to stimuli such as hands and a head. The head is reported to be superior to the body for spatial directional perception. In this paper, we propose Virtual Whiskers, a spatial directional guidance technique by haptic stimulation of the cheeks using tiny robot arms attached to a Head-Mounted Display (HMD). We deploy photo reflective sensors attached to the tip of 2 robotic arms to detect the distance between the tip and the cheek surface. Using the robot arms, we stimulate a point on the cheek obtained by calculating an intersection between the cheek surface and the target direction. We experimentally investigated how accurately participants identify the target direction provided by our guidance method. We evaluated an error between the actual target direction and the participant's pointed direction. The experimental result shows that our method achieves the average absolute directional error of 2.76 degrees in the azimuthal plane and 7.32 degrees in the elevation plane. We also conducted a spatial guidance experiment to evaluate task performance in a target search task. We compared the condition of only vision and vision with haptics for task completion time. The average of task completion time in visual-only condition was M=12.45 s, SD=14.51 s, and visual with haptic condition resulted in M=6.91 s, SD=5.48 s. Statistical test revealed a significant difference in task completion time between the visual condition and the visual+haptic condition.