Avatar Disembodiment and Pain Reduction

Open Human-Computer Interaction Computer Science Games Engineering Bachelor Master Project Thesis No Affiliation

Avatar Disembodiment and Pain Reduction

Overview

Developing and evaluating a VR application for reducing Pain using Avatar Disembodiment Techniques

Motivations

In 2017, [Pamment et al, 2017] researchers induced a sensation of disembodiment in patients by synchronising visual and tactile stimuli using virtual reality headsets and video cameras (see image below - modified image from [Pamment et al, 2017])

The results demonstrated that these “out-of-body” experiences (i.e., seeing your body and the world from a location outside your physical body[Blanket et al. 2016] [Ehrsson et al 2007, Lenggenhager et al 2007])led to a significant average pain reduction of 37% among participants. These findings suggest that multisensory integration plays a crucial role in how the brain perceives long-term physical suffering. Ultimately, the research highlights the potential for innovative psychological interventions to assist in the management of persistent medical conditions.

In the experiment by [Pamment et al., 2017], in the back-stroking condition, participants wore a head-mounted display to view a video feed of their own back from a camera placed 1.5 meters behind them, while an experimenter stroked their physical back with a stick. This visual feedback was either presented in real time to perfectly match the physical sensation or delayed via a pre-recorded video to create a sensory mismatch. When the visual and physical strokes were synchronized, participants experienced a strong “out-of-body” illusion that significantly reduced their chronic pain intensity, and the degree of this pain relief directly correlated with the strength of the illusion. The participants in the study experienced a wide variety of chronic pain conditions that had persisted for a minimum of six months, with many having suffered for more than five years.

The types of chronic pain varied significantly among patients, ranging from localized issues to widespread pain felt all over the body. Specifically, the conditions included: Localized Pain Conditions: Sciatica (affecting hips, legs, and feet), migraines, spinal cord injuries, herniated or slipped spinal discs, shoulder and neck conditions, osteoarthritis (affecting hips, knees, and hands), irritable bowel syndrome (IBS), endometriosis, spinal and hip nerve damage, and post-surgical complications. Widespread Pain Conditions: Fibromyalgia (a rheumatic condition causing muscular or musculoskeletal pain all over the body), muscular dystrophy, and diabetic neuropathy. The study aimed to test the “out-of-body” illusion on this diverse range of centrally mediated chronic pain types, which differ from acute (protective) pain and are considered diseases in their own right. Overall, the study found that patients experienced a maximal average pain reduction of 37% after the synchronous conditions, where the out-of-body illusion was successfully induced

More recently, Unruh and colleagues demonstrated that two types of virtual disembodiment techniques purely based on viewpoint gradual transition: a virtual body’s behind view and facing view transitions elicited a significant virtual disembodiment perception as well as influencing time perception [Unruh et al, 2024] (see figure below and video)

Goal

The main goal of this project is to investigate further the potential of systematically reducing chronic pain with VR technology, especially through existing or novel avatar disembodiment techniques (i.e., the process of dissociation from a previously embodied virtual body [Unruh et al., 2024]). Overall, inducing an illusion where an individual’s subjective sense of self-location and body-ownership is visually displaced from their actual physical body onto a real-time, third-person digital representation of themselves.

We hypothesize that such an avatar disembodiment will shift bodily awareness away from the physical self, thereby mitigating chronic pain levels or perceptions by disrupting standard somatic integration. The human brain usually integrates vision, touch (tactile), and internal positioning (proprioception) into a single unified percept: “My body is here.” Therefore, disrupting this process may disrupt pain perception. The core idea is to use VR to “trick” your brain into feeling that its primary attention (and therefore its pain) is located outside your physical body.

Task

• Designing and performing a novel experiment investigating the relationship between virtual disembodiment and pain perception in Virtual Reality (VR).

Observation

• A Starting point can be provided
  • An Unreal Engine VR Project
  • with Avatar Embodiment & Disembodiment Techniques
  • used one of our previous experiments from [Unruh et al, 2024]

Related Projects

• Out-of-Body Experience In XR

Prerequisites

• Game-Engine (Unreal or Unity)
• VR Development
• HCI
• Research Methodology

Main References

Pamment, J., & Aspell, J. E. (2017). Putting pain out of mind with an ‘out of body’illusion. European Journal of Pain, 21(2), 334-342. Download

Unruh, Fabian, Jean-Luc Lugrin, and Marc Erich Latoschik. “Out-of-virtual-body experiences: Virtual disembodiment effects on time perception in VR.” Proceedings of the 30th ACM symposium on virtual reality software and technology. 2024. Download

Blanke, Olaf, Nathan Faivre, and Sebastian Dieguez. 2016. “Leaving Body and Life Behind: Out-of-Body and Near-Death Experience.” In The Neurology of Conciousness, 323–47. Elsevier. Download

Additional References

Bourdin, Pierre, Itxaso Barberia, Ramon Oliva, and Mel Slater. 2017. “A Virtual Out-of-Body Experience Reduces Fear of Death.” PloS One 12 (1). Public Library of Science San Francisco, CA USA: e0169343.

Ehrsson, H Henrik. 2007. “The Experimental Induction of Out-of-Body Experiences.” Science 317 (5841). American Association for the Advancement of Science: 1048–48. doi:10.1126/science.1142175.

Lenggenhager, Bigna, Tej Tadi, Thomas Metzinger, and Olaf Blanke. 2007. “Video Ergo Sum: Manipulating Bodily Self-Consciousness.” Science 317 (5841). American Association for the Advancement of Science: 1096–99

Neumann, I., Pauli, P., Andreatta, M., & Käthner, I. (2024). Social support of virtual characters reduces pain perception. European Journal of Pain, 28(806-820). https://doi.org/10.1002/ejp.2220

Neumann, I., Käthner, I., Gromer, D., & Pauli, P. (2023). Impact of perceived social support on pain perception in virtual reality. Computers in Human Behavior, 139, 107490. https://doi.org/10.1016/j.chb.2022.107490

Contact Persons at the University Würzburg