Investigating the Role of an Embodied Avatar in Virtual Reality on Pain Alleviation, the Sense of Embodiment, and Brain Waves in Patients with Chronic Pain

For about two decades, many studies have shown the effectiveness of Virtual Reality (VR) as an alternative intervention for pain reduction in patients with acute and chronic pain. One of the possible mechanisms of VR effect is associated with Sense of Embodiment (SoE). To uncover the underlying brain mechanisms of VR analgesia, in this thesis, I am exploring if having an avatar in VR reduces pain through activation of SoE using Electroencephalography (EEG). To address this, I ran an exploratory pretest-posttest pilot study on a VR intervention called Virtual Meditative Walk (VMW) with and without an avatar. 14 participants with Chronic Pain (CP) (> 18) were recruited and used VR. Subjective pain score, and EEG signals were recorded before and after the intervention. Also, SoE scores were collected after VR. To analyze the data, alpha and theta Power Spectral Density (PSD) and Peak of Theta-Alpha Frequency (PTAF) for subjects across conditions were calculated. Results showed a higher but insignificant pain reduction and SoE trend in the Avatar group. The EEG analysis also demonstrated an increase in alpha in time for both conditions, with a significantly lower post-Rest frontal alpha for the Avatar group. The PTAF was also significantly higher for the Avatar group. Overall, the Avatar group showed promising but inconclusive results in terms of pain reduction and SoE, with some differences in brain activity observed in the EEG analysis. This study is a step toward understanding the role of an avatar in VR analgesia and designing more effective VR scenarios for patients with CP.