Neurophysiological and psychophysical mechanisms associated with immersive virtual reality-induced hypoalgesia: a systematic review
Although growing evidence supports immersive virtual reality (IVR) as a nonpharmacological intervention for pain management, the mechanisms by which IVR induces hypoalgesia are still under debate. In this study, we review and evaluate candidate neuro...
Key Findings
Although growing evidence supports immersive virtual reality (IVR) as a nonpharmacological intervention for pain management, the mechanisms by which IVR induces hypoalgesia are still under debate. In this study, we review and evaluate candidate neurophysiological and psychophysical mechanisms underlying IVR-induced hypoalgesia and their experimental evidence. A preregistered systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, utilizing the databases Web of Science, Medline (through PubMed), SCOPUS, and APA PsycINFO. A total of 28 studies were included, involving 1142 participants (673 women [59%]). Of these, 78 (6.8%) experienced acute pain, 171 (15%) chronic pain, and 869 (76%) were exposed to experimental pain inductions. Risk-of-bias assessment ranged from low (n = 1; 3.5%), with some concerns (n = 16; 57.1%), to high (n = 11; 39.3%). The overall quality of studies ranged from fair (n = 6; 21.5%) to good (n = 21; 75%) to excellent (n = 1; 3.5%). Our synthesis suggests that IVR-induced hypoalgesia correlates with increased brain activity, specifically in nuclei implicated in descending pain modulation, and altered autonomic responses, specifically enhanced parasympathetic system activity. Similarly, IVR-induced hypoalgesia is associated with changes in psychophysical pain tests, such as increased pain tolerance and/or thresholds. However, caution is warranted when interpreting these results, as 89.3% of the studies assessed only the immediate effects of a single IVR session, and intervention protocols were highly heterogeneous. Furthermore, most studies tested pain-free subjects using experimentally induced pain (n = 20), limiting extrapolation to clinical populations. We conclude that experimental designs allowing causal inference-ideally through mediation analyses-are currently lacking and urgently needed to elucidate the mechanisms underlying IVR-induced hypoalgesia.
Why This Matters for Body-Mind Practice
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