Using electrophysiological measures to evaluate the sense of presence in immersive virtual environments: An event-related potential study.

Sense of presence has been often explored in the context of virtual reality (VR) and immersive visual technologies; however, standardized and objective measures of the sense of presence have been difficult to find. Studies attempting to find physiological correlates of sense presence using electroencephalography (EEG) have reported mixed results. In the present study, we used brain event-related potentials (ERPs) elicited by auditory stimuli to identify an objective physiological index of sense of presence during VR, attempting to replicate the findings of previous studies and explain the heterogeneity of results reported in the literature. Participants in our experiment were asked to experience an immersive virtual environment using a modern head-mounted display while passively hearing task-irrelevant frequent standard and infrequent deviant tones as in a classic auditory oddball paradigm. Subsequently, they were asked to complete a battery of questionnaires aimed to estimate their sense of presence during the VR. EEG and questionnaire data from three-seventh participants were analyzed. ERP components evoked by the auditory stimuli were then analyzed. Late ERP components (after 450 ms from stimulus onset) registered over central brain areas were associated with the sense of presence as measured with questionnaires, while earlier components were not associated with presence. The use of different questionnaires and the content of the VR environment may both be a plausible explanation for heterogeneous results as reported in previous studies. The present study showed that late ERP components recorded over the central brain may represent good electrophysiological correlates of the subjective sense of presence.