What is it called, when people lean forward in the real world while moving forward in a Virtual Environment?

Question

A test subject wears a Virtual-Reality-Headset (like the HTC-Vive). When the test subject moves forward in the virtual world and stands still in the real world, the subject tends to lean forward in the real world. But obviously there is no need in the real world to learn forward.

Another comparable situation: My friend and I play a racing game. When my friend is about to turn his car (in the video game) he tilts his controller like if it was a real driving-wheel, although the controller just has a stick and buttons.

I've looked around and only found Mel Slater's Presence Research so far, but no definite term for the phenomenon I'm looking for. It's like, they're adjusting themselves in the real world. Is there even a term for that?

Answer 1

There is no real term so far, because it's considered a side effect of vection or 'Illusion of self-motion'. In the case of a virtual environment, where the test subject stands still and moves in the virtual world, vection would be called as: Visually-Induced Self-Motion Illusion. Generally, when a subject stands still and the environment moves, it's called optokinetic.

Ref:

• M. Fischer, “Kornmüller a. optokinetisch ausgelöste bewegungswahrnehmung und optokinetischer nystagmus,” J für Psychol und Neurol, vol. 41, pp. 273–308, 1930
• A. Tschermak, Optischer Raumsinn, pp. 834–1000. Berlin, Heidelberg: Springer Berlin Heidelberg, 1931
• J. Dichgans and T. Brandt, Visual-Vestibular Interaction: Effects on Self- Motion Perception and Postural Control, pp. 755–804. Berlin, Heidelberg: Springer Berlin Heidelberg, 1978
• B. E. Riecke, D. Feuereissen, J. J. Rieser, and T. P. McNamara, “Selfmotion illusions (vection) in vr—are they good for anything?,” in 2012 IEEE Virtual Reality Workshops (VRW), pp. 35–38, IEEE, 2012
• S. Palmisano, R. S. Allison, M. M. Schira, and R. J. Barry, “Future challenges for vection research: definitions, functional significance, measures, and neural bases,” Frontiers in psychology, vol. 6, p. 193, 2015