Effect of Vibrations on Impression of Walking and Embodiment With First- and Third-Person Avatar

We investigate how underfoot vibrotactile feedback can be used to increase the impression of walking and embodiment of static users represented by a first- or third-person avatar. We designed a multi-sensory setup involving avatar displayed on an HMD, and a set of vibrotactile effects displayed at every footstep. In a first study (N = 44), we compared the impression of walking in 3 vibrotactile conditions : 1) with a "constant" vibrotactile rendering reproducing simple contact information, 2) with a more sophisticated "phase-based" vibrotactile rendering the successive contacts of a walking cycle and 3) without vibrotactile feedback. The results show that overall both constant and phase-based rendering significantly improve the impression of walking in first and third-person perspective. Interestingly, the more realistic phase-based rendering seems to increase significantly the impression of walking in the third-person condition, but not in the first-person condition. In a second study (N=28), we evaluated the embodiment towards first- and third-person avatar while receiving no vibrotactile feedback or by receiving vibrotactile feedback. The results show that vibrotactile feedback improves embodiment in both perspectives of the avatar. Taken together, our results support the use of vibrotactile feedback when users observe first- and third-person avatar. They also suggest that constant and phase-based rendering could be used with first-person avatar and support the use of phase-based rendering with third-person avatar. They provide valuable insight for stimulations in any VR applications in which the impression of walking is prominent such as for virtual visits, walking rehabilitation, video games, etc.