The essence of immersive virtual reality (VR) is the illusion it gives users that they are inside the computer-generated virtual environment. This unusually strong illusion is theorized to contribute to the successful pain reduction observed in burn patients who go into VR during woundcare (www.vrpain.com) and to successful VR exposure therapy for phobias and post-traumatic stress disorder (PTSD). The present study demonstrated for the first time that subjects could experience a strong illusion of presence during an fMRI despite the constraints of the fMRI magnet bore (i.e., immobilized head and loud ambient noise).
Hoffman, H. G., Richards, T., Coda, B., Richards, A., & Sharar, S. R. (2003). The Illusion of Presence in Immersive Virtual Reality during an fMRI Brain Scan. CyberPsychology & Behavior, 6(2), 127–131. https://doi.org/10.1089/109493103321640310