Manipulating Bodily Self-Consciousness Without Multisensory Input; An Explorative Study on the Out-of-Body Illusion
D. Fuchten · Utrecht University Repository (Utrecht University) · 2017
The Out-of-Body Illusion is a bodily illusion using visuotactile input to create the feeling as if you are outside your own body, looking at yourself from a distance. The present study investigated whether multisensory input was necessary to induce this illusion, and if higher levels of visual imagery and/or dissociation were associated with the experienced strength of the illusion. 33 participants completed a synchronous, asynchronous and visual only condition of the OBI, after which the strength of the illusion was measured objectively with a self-localisation task and subjectively with an embodiment questionnaire. Questionnaires on visual imagery, dissociation, immersive tendencies and presence were included. The results showed that there was no difference between the experienced strength of the illusion in the synchronous and visual only condition, as measured by the embodiment questionnaire. Furthermore, levels of visual imagery and dissociation did not seem to contribute to the experienced strength of the illusion. The feeling of being present in the virtual reality environment however did seem to contribute to the experienced strength of the illusion, but only in the visual only condition. Taken together, the findings show that multisensory input is not necessary to induce the illusion; visual input seems to be sufficient. Possibly the input given to the participants is realistic and immersive enough to immediately let them believe what enters their visual system. The feeling of presence in the visual only condition seems to contribute to experiencing a stronger illusion; perhaps to experience the illusion without tactile input, participants had to feel more present in the environment than in the condition with tactile input.