The Effect of Vestibular Stimulations on Virtual Reality Based Bodily Self Consciousness

Abstract

Background Consciousness is classically described as alertness and awareness. Damasio claims that this change is not enough for consciousness to emerge, that a basic element is missing, which is the "self". The purpose of this study was to investigate the role of electrical vestibular stimulation (VS) in the formation of bodily self-consciousness in healthy individuals by utilizing brain hemodynamic activations with the functional Near Infrared Spectroscopy (fNIRS) system. Methods The study protocol included three sessions: a session without VS, a VS session with application on the right temporo-parietal junction (rTPJ) and a VS session with application on the mastoid level with transcranial direct current stimulation (tDCS). Results In VS provided at the rTPJ level, unlike the other sessions, increased hemodynamic activation was observed at primary somatosensory cortex-supramarginal gyrus in the left lobe and in the supramarginal gyrus in the right lobe. In VS provided on the mastoid level, increased hemodynamic activation was observed in secondary somatosensory cortex-ventral posterior cingulate cortex connection on left lobe, which we did not observe in other sessions. Conclusion After artificial VS, the perception of bodily ownership in individuals requires coding of personal space information as well as vestibular information processing and extrapersonal space integration information.