Surface somatosensory sensitivity and changes to autonomic nerve activity in response to electrical current stimulation were evaluated in a virtual reality (VR) environment by having 20 participants view a intermediate, heat, and cold VR videos. Pain Vision was used to calculate pain ratios (PR), and to evaluate surface sensory nerve electrical stimulation. Electrocardiography was performed to assess autonomic activity and the low frequency/high frequency ratio (LF/HF) was calculated.
The results showed that sympathetic nerve activity increased, and parasympathetic nerve activity was suppressed, upon watching the heat and cold videos. In addition, PR values were low while viewing the VR videos of all conditions: intermediate, heat, and cold.
The present study suggested that acute pain, related to somatic pain, was alleviated by viewing VR videos inducing the impression of heat and cold. In contrast, it was found that there was no difference in acute pain sensitivity between heat and cold VR images and intermediate VR images.