This study aims to investigate how immersion in VR affects pain perception, especially when pain anticipation is affected by previous instructions. Additionally, we aimed to investigate how autonomic nervous responses change during pain anticipation. We compared autonomic nervous responses and subjective pain intensity in healthy adults after viewing VR content and after viewing regular two-dimensional (2D) content, which served as a sham VR condition.
This study included 20 healthy university students aged ≥18 years (9 females, mean age: 21.2 ± 0.62 years). A noxious heat stimulus was applied to the right forearm with a heat stimulation device. Three temperature levels were used: 47℃, 48℃, and 49℃. Participants were given prior instructions, such as “a weak stimulus will be presented” for the 47℃ and some of the 48℃ stimuli, and “a strong stimulus will be presented” for the remaining 48℃ and 49℃ stimuli. Participants rated the intensity of pain with a Numerical Rating Scale (NRS) after each stimulus. Autonomic nervous responses during pain anticipation were measured with skin conductance response (SCR). The VR content consisted of noninteractive three-dimensional videos viewed through a head-mounted VR display. The VR and 2D conditions (viewed on a liquid-crystal display monitor) were alternated with an interval session in between.
NRS scores indicated that pain perception differed based on the previous instructions (strong or weak stimulus), even when the temperature was similar. However, VR and 2D conditions indicated no association regarding pain perception. A significant decrease was observed during pain anticipation in the VR condition compared to the other conditions in terms of SCR amplitude. This decrease was consistent across the board, demonstrating no interaction with stimulus temperature or previous instructions.
This study confirmed that VR immersion affected autonomic nervous responses during pain anticipation, although it did not affect subjective pain intensity. The results indicate that a reduction in autonomic arousal during pain anticipation may be one of the mechanisms involved in VR-induced analgesia.
VR has effectively relieved pain during invasive medical procedures, but little research has been conducted on its effects on chronic musculoskeletal pain, which is a common target in physical therapy. As this study indicates, more effective pain management strategies that combine VR with physical therapy may be developed by gradually clarifying how VR affects various physiological processes.
Pain Perception
Autonomic Nervous Responses
