Investigating the influence of neck muscle vibration on illusory self-motion in virtual reality

The illusory experience of self-motion known as vection, is a multisensory phenomenon relevant to self-motion processes. While some studies have shown that neck muscle vibrations can improve self-motion parameter estimation, the influence on vection remains unknown. Further, few studies measured cybersickness (CS), presence, and vection concurrently and have shown conflicting results. It was hypothesized that 1) neck vibrations would enhance vection and presence, and 2) CS to negatively relate to presence and vection, whereas presence and vection to positively relate to one another. Thirty-two participants were visually and audibly immersed in a virtual reality flight simulator and occasional neck muscle vibrations were presented. Vection onset and duration were reported through button presses. Turning angle estimations and ratings of vection quality, presence, and CS were obtained after completion of the flights. Results showed no influence of vibrations on turning angle estimation errors, but a medium positive effect of vibrations on vection quality was found. Presence and vection quality were positively related, and no strong association between CS and presence or vection was found. It is concluded that neck vibrations may enhance vection and presence, however, from the current study it is unclear whether this is due to proprioceptive or tactile stimulation.