The whole idea behind virtual reality is that you don’t really know what’s going on in the world around you. You only know what your senses tell you is there. If you can fake out your vision, for example, then your brain won’t realize you are floating in a tank providing power for the robot hordes. However, scientists in Japan think that you can even fool your feet into thinking they are walking when they aren’t. In a recent paper, they describe a test they did that combined audio cues with buzzing on different parts of the feet to simulate the feel of walking.
The trick only requires four transducers, two on each foot. They tested several different configurations of what the effect looked like in the participant’s virtual reality headgear. Tests were performed in third person didn’t cause test subjects to associate the foot vibrations with walking. But the first-person perspective caused sensations of walking, with a full-body avatar working the best, compared to showing just hands and feet or no avatar at all.
Making people think they are walking in VR can be tricky but it does explain how they fit all that stuff in a little holodeck. Of course, it is nice if you can also sense walking and use it to move your avatar, but that’s another problem.
This sort of thing was shown 10 years ago by a friend of mine. No VR or electrodes needed. I think the method was place the subject with a view of one of their hands and a dummy opposing hand. Stroke gently the subject’s visible hand for a period, then stroke the dummy hand. The subject felt they were being stroked on their non-visible hand when the dummy hand was being stroked. From what I can remember it was the gentle touch that was significant, i.e. you couldn’t say stab one hand with a blunt object then stab they dummy hand for the same effect.
https://en.wikipedia.org/wiki/Body_transfer_illusion
Yeah that’s probably the theoretical basis of this work. However, making someone feel like they’re walking is probably a lot more useful than making someone feel like you’re stroking their hand. The nature of research: it’s usually incremental, and demonstrating that the principle holds at each extension still has value.