Background and aims: Virtual reality (VR) has shown to reduce pain scores in previous studies, however, outcome parameters are mostly of subjective nature and susceptible to bias. The purpose of this study was to investigate the effect of VR on cortical processing of pain-related evoked potentials (EPs) and pain scores. Additionally, we aimed to identify personal characteristics affecting a potential VR effect.
Methods: The analgesic effect of passive and active VR was investigated compared to a control condition using a randomized cross-over study design in 30 healthy volunteers. Subjects received noxious electrical stimuli at random intervals using a concentric electrode applied on the forearm during all conditions. EPs recorded at Cz were extracted time locked to the stimuli. 
Results: Active VR significantly decreased amplitudes of N1 and P3, and significantly lowered pain scores compared to passive VR or no VR. Passive VR had no significant effect on EPs and pain scores. Age was significantly correlated to pain scores in both passive and active VR conditions, with older subjects demonstrating larger VR effects. Significant age-related effects were also found in N1 and P3 amplitudes of active minus passive VR, suggesting that the interactive component of VR is less important in elderly. Other characteristics had no significant impact on VR effects. 
Conclusions: Active VR decreases both subjective pain experience and cortical pain processing. Passive and active VR seem to be more effective in reducing subjective pain relief in older subjects, while the interactive component seems less necessary according to pain related EPs.

THE EFFECT OF VIRTUAL REALITY ON EVOKED POTENTIALS AND PAIN SCORES