Anwesha Das¹ (), Daw-An Wu¹, Shinsuke Shimojo¹, Matilda Cederblad¹; ¹California Institute of Technology (Caltech)

Virtual Reality (VR) can give us visual input from a new vantage point. To what extent does one adopt such a vantage point in sensory and motor processing? We examine this with a conditional mirroring effect found in tactile perception, which behaves as if the observer “views” the trace from an egocentric internal visual vantage point. E.g. if I trace the letter ‘d’ on your palm with your hand facing forwards, you perceive ‘b.’ Participants (N=6) wore a VR headset receiving video from a webcam facing the participant. They started the experiment with their eyes closed and reported perceived letters [b,d,p,q] traced on their palm, which could face towards or away from them (tactile baseline). Next, they opened their eyes, and letters were traced over the far side of the hand without touching it (VR-vision-only control). Finally, they kept their eyes open as letters were traced onto the hand (test condition). Following this, there was a short training period where they interacted with real-world objects while viewing the VR perspective. Then all previous tests were repeated in reverse order. In the initial eyes-closed baseline, they felt the tracings from an egocentric vantage point. They tended to mirror letters when the palm was facing away (85±5.7%), but not when it was facing towards them (2.1±2.3%). When they viewed the VR (no tactile input), the external visual perspective dominated. The mirroring effect disappeared on the outward-facing palm (0±0%, p<<.01, t=16), and started to appear on the inward-facing palm, even though it was not visible to the camera (19±6.1%, p=.01, t=3.7). Training did not appreciably increase this, thus far (24±5.6%, p=.51, t=.71). This indicates that external vantage points in virtual reality environments lead to re-mirroring of tactile mappings in accordance with the new visual perspective.