Augmenting Virtual Reality Exposure Therapy for Acrophobia With Tactile Feedback and Point-based Rewards

Exposure therapy is one of the most potent techniques available for treating anxiety-related disorders, including specific phobia. However, estimates suggest that 10-48% of anxiety patients do not fully respond to exposure therapy. Meta-analyses demonstrate that virtual reality exposure therapy (VRET) is equally effective as traditional, in vivo ('in life') exposure therapy. Furthermore, individuals with anxiety disorders report greater preference (and lower likelihood of treatment refusal) for VR, rather than in vivo, exposure therapy. Although VRET has well-established efficacy and is rapidly growing in popularity, there has been very little research evaluating how specific elements of VR game design might be used to improve outcomes from VRET. This study evaluates two game design elements that we hypothesize will improve VRET outcomes: tactile feedback and a point-based reward system. Tactile feedback (TF; i.e., touching a real object that matches an element in the VR environment) enhances sense of presence in VR. Higher presence activates anxiety during VRET, which is essential for promoting the active mechanisms of exposure therapy and may also improve treatment retention. On the other hand, point-based rewards (PR) in games enhance sense of competence (i.e., sense of progress and achievement), and increase both enjoyment and likelihood of future use of games. Furthermore, several studies demonstrate that PR improves traditionally difficult-to-change health behaviors, such as increasing exercise frequency and reducing misuse of pain medications. Although this research is promising, the impact of PR on VRET is unknown. To test the influence of TF and PR on VRET outcomes, we will randomize participants with acrophobia to receive (a) standard virtual reality exposure therapy, (b) VRET with tactile feedback, (c) VRET with a point-based reward system, or (d) VRET with tactile feedback and a point-based reward system. Participants' fear reactivity will be assessed with behavioral, physiological, and subjective/self-report measures at baseline, post-treatment, and follow-up.