Out-of-body illusion induced by visual-vestibular stimulation

In her research Hsin-Ping Wu explores the connection between the sense of self and the brain’s body representation, particularly bodily self-consciousness, involving self-identification, self-location, and first-person perspective. Out-of-body experiences (OBEs) have been argued to present an altered states of bodily self-consciousness and provide a unique avenue to explore its multisensory foundations. OBEs often involve a sense of being outside one's body and elevated self-location associated notably with vestibular sensations and an elevated first-person perspective; however, despite their correlation with altered processes in temporo-parietal cortex and the vestibular system, comprehensive studies on OBEs in both clinical and healthy populations remain limited.

Here, Hsin-Ping Wu and colleagues developed a novel approach by combining visual and vestibular stimulation to induce OBE-like sensations. They used a custom-made motion platform to displace participants in the earth-vertical direction while presenting a visual scenario simulating OBE disembodiment in immersive virtual reality and exposing participants to visual and vestibular cues with different congruencies.

The results show that congruency between visual and vestibular cues is crucial for inducing OBE-like sensations and influencing bodily self-consciousness, revealing that alterations in self-location, feelings of disembodiment, and sensations of lightness are associated with the congruency of visual and vestibular signals (with stronger effects when vestibular direction is congruent with visual self-motion direction). Moreover, participants with strong visual-field dependency had stronger OBEs. Overall, this work points to the important role of vestibular processes in OBEs, especially the complex interplay between visual and vestibular self-related cues and sheds light on the cognitive and neural mechanisms of bodily self-consciousness.

These findings will also inform the design of novel cognitive behavioral therapies as well as meditative practices linked to bodily self-consciousness and may lead to new diagnostic and therapeutic strategies in patients with neurological and otological diseases of the inner ear and related central nervous pathways.