I examined how thermal feedback affected people's sense of direction.

It is known that people do not notice if their rotation in the virtual world does not exactly match their rotation in the physical world. The technique of shifting the rotation in the virtual world from that in the physical world is called redirection, and the basic technique is to shift the visual feedback on a head-mounted display (HMD). However, if this shift is larger than a certain threshold, people will notice it. I thought that if we shift not only the visual presentation but also the heat from the heat source in the VR space at the same time, we could trick people more and increase this threshold value.

CONCEPT

Redirection is a promising approach to realize the exploration of vast virtual space in a limited physical space. Researchers have explored different combination of modalities to trick human minds more and raise the threshold where people notice the redirections. Matsumoto et al. achieved a higher threshold value by combining visual and haptic feedback. One sunny day, I was walking by the Kamo River in Kyoto. I closed my eyes and I was able to keep walking straight by using the sun's warmth as a cue. That is the moment I realize that humans see the world not only through the eyes but also through the skins. If effective redirection can be achieved with non-contact thermal sensation, it could be a promising approach because, unlike other tactile cues, it does not limit user behavior.

EXPERIMENT

We examined visual-only and visual&thermal stimuli conditions. For each condition, we measured the just-noticeable difference of rotation gain (shift) between the virtual and physical space.

RESULTS

The results show a trend that thermal feedback results in a higher threshold, but it did not show any statistically significant differences between visual-only and visual&thermal conditions. Further study with more powerful thermal feedback and a different experiment design (waling task) is expected.

CREDITS

Sosuke Ichihashi
Arata Horie
Zendai Kashino
Hiroto Saito
Sohei Wakisaka
Masahiko Inami