Psychophysiological correlates of virtual reality: A review

The recording and measurement of central and peripheral nervous system resp onses can provide important information during the development and the appl ication of virtual reality (VR). Although studies on electroencephalographi c, evoked potentials, and peripheral psychophysiological changes in connect ion with VR exposure are still preliminary, they show that reliable data ca n be obtained even in immersive VR conditions. There is no firm evidence th at neurophysiological equipment-sensors and cables-may increase subjects' d iscomfort and affect their ability to interact with the virtual environment s, but additional study is needed to clarify this issue. Suggestions as to how to limit potential interferences are summarized here. Two main lines of research are emerging: one seeking psychophysiological correlates of react ion and adaptation to stimuli and task variables in an attempt to understan d more about human-VR interaction, and the other looking for ways to use ps ychophysiological responses to automatically control aspects of the virtual environments or other external devices. The main results emerging from the first group of studies indicate that psychophysiological measures of brain activity-notably EEG and event-related responses-may be used to distinguis h between automatic and controlled modes of processing. Additionally, perip heral measures, notably skin-resistance levels, are proposed as objective c orrelates of presence and of the outcome of specific VR-based desensitizati on therapies. There is no clear-cut evidence that brain waves may index unw anted effects on the central nervous system of VR exposure, but this issue deserves further study. The results of the second line of research seem to indicate that VR-induced psychophysiological responses can be used to devel op assistive devices for people with disabilities or to control hands-free interaction within any virtual environment (for example, in highly demandin g conditions). A related and promising field of application is that of neur o-feedback, wherein VR may play an important role in increasing the motivat ional/attentional span of clients, and, ultimately, the effectiveness of tr eatment protocols. Given these premises, it is suggested that research on p sychophysiological correlates of VR should be incremented along the lines a lready delineated and possibly include also groups of subjects at risk for adverse affects.