Influence of User Posture and Virtual Exercise on Impression of Locomotion During VR Observation

Abstract

A seated user watching his avatar walking in Virtual Reality (VR) and imagining being walking may have an impression of walking. In this paper, we show that such impression can be extended to other postures and other locomotion exercises. We present two user studies in which participants worn a VR headset and observed a first-person avatar realizing virtual exercises. In the first experiment, the avatar walked and participants (n=36) tested the simulation in 3 different postures (standing, sitting and Fowler's posture). In the second experiment, other participants (n=18) were sitting and observed the avatar walking, jogging or stepping over virtual obstacles. We evaluated the impression of locomotion by measuring the impression of walking (respectively jogging or stepping) and embodiment in both experiments. The results show that participants had the impression of locomotion in either sitting, standing and Fowler's posture. The Fowler's posture however significantly decreased both the level of embodiment and the impression of locomotion. Moreover the sitting posture seems to decrease the sense of agency compare to standing posture. Results also show that the majority of the participants elicited an impression of locomotion during walking, jogging and stepping virtual exercises. The embodiment was not influenced by the type of virtual exercise. Overall, our results suggest that an impression of locomotion can be elicited in different users' postures and during different virtual locomotion exercises. They provide valuable insight for numerous VR applications in which the user observes a self-avatar moving, such as gait rehabilitation, training, video games, etc.

Multi-sensory display of self-avatar's physiological state: virtual breathing and heart beating can increase sensation of effort in VR

“…The sitting position was chosen as it is a common gaming position which does not induce much sensation of effort and could benefit from our system. Also, it induces as much embodiment as standing when observing a walking simulation and is more comfortable [46]. Participants were told that, during the simulations, they could look around and had to focus on their sensations and relationship with their avatar.…”

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

“…We limited such an effect so as not to bias the results by reducing the walking speed, keeping the direction constant, and dampening the head swing. The same animation and settings were also used in [5] with participants novice in VR and they did not experience cyber-sickness so it seems unlikely that it was caused in the simulation but this should be investigated in a future study. As it stands, our results suggest that future applications should consider the possibility of not simulating vibrotactile feedback for 1PP avatar so as not to affect the IoW of some participants.…”

“…Previous work has evaluated embodiment toward 1PP and 3PP avatars [4], [5] when observing a virtual walk. Our results appear to be lower, especially for 1PP.…”

“…Other parameters of the simulation could have contributed to this effect. For example, we showed pink noise to the participants in order to isolate them from the outside world, especially from the tactors, whereas in the case of [5] the noise of footsteps was simulated. The results of Kokkinara et al [4] also suggested that head bobbing could be detrimental to some components of embodiment while it was simulated in our experiments.…”

“…Even though the users remained static, they can have an impression of walking (IoW) and a sense of embodiment, the feeling of being inside (self-location), controlling (agency), and having a virtual body (ownership) [3], towards a walking avatar [4], [5]. In previous work, Kokkinara and al.…”