Burnar: Involuntary heat sensations in augmented reality

Augmented Reality systems that run interactively and in real time, using high quality graphical displays and sensational cues, can create the illusion of virtual objects appearing to be real. This paper presents the design, implementation, and evaluation of BurnAR, a novel demonstration which enables users to experience the illusion of seeing their own hands burning, which we achieve by overlaying virtual flames and smoke on their hands. Surprisingly, some users reported an involuntary warming sensation of their hands. Based on these comments, we hypothesized that stimulation of multiple sensory modalities presented in this AR environment can induce an involuntary experience in an additional sensory pathway: observation of virtual flames resulting in a heat sensation. This cross-modal transfer, known as virtual synesthesia, is a temporary experience which affects some people who are not synesthetes and only lasts for a short time during the illusory experience. To verify our hypothesis, we conducted an exploratory study where participants experienced the BurnAR demonstration under controlled conditions.