PAIN-EX: Probing Alternative Interventions for Neutralizing pain EXperiences via Embodiment in Virtual Reality

One of the tailored approaches that is particularly promising for chronic pain treatment is the one described by Daniele Di Lernia and colleagues as “interoceptive modeling.”6 It assumes the existence of residual interoceptive images (so-called ghosts) of pain. These mental representations of pain may be overwritten to induce permanent alterations to the cognitive and neurological system by a two-step process. First, the interoceptive representation of pain is visualized through external feeds in an internally coherent and multisensorily congruent mode to best fit the pain experienced by the patient (mimicking phase). Second, these internal representations are gradually manipulated to counteract the internal feed (modeling phase).\r\nHere, virtual embodiment provides optimal grounds for mimicking and modeling interoceptive information. The embodied virtual body part may be visually customized to fit the person's interoceptive pain experience and subsequently counteracted to alter pain representations effectively. Initial experimental studies underline the potential of visually altering the affected body part in VR. For instance, changing the color (i.e., blue) or material (i.e., stone) of a virtual arm significantly impacts the person's perception of this arm (i.e., to be colder or heavier).4 Despite these positive results, the usefulness of virtual embodiment, and of interoceptive modeling in particular, for therapeutic pain management is unclear. To our knowledge, interoceptive modeling has only been theorized so far. Empirical evidence is needed to test its suitability for pain treatment.\r\nIn view of this desideratum, the PAIN-EX project aims to test whether interoceptive modeling in a fully immersive VR is effective in decreasing pain intensity. For this purpose, the Pediatric Virtual Reality Laboratory at the Department of Pediatrics and Adolescent Medicine at the Medical University of Vienna and the Humane Technology Laboratory at the Department of Psychology of the Catholic University of Milan in collaboration with the Faculty of Computer Science at the University of Vienna will develop and test a novel VR-based application. A customized virtual version of participants' arms matching their actual size and skin tone, as well as visuomotor feedback, will be used to induce embodiment. All participants will receive topical application of capsaicin cream to the inner side of the nondominant forearm to induce thermal pain experimentally.