Respiration Entrainment in Virtual Reality by Using a Breathing Avatar

Increasing evidence points to the role of interoception in body perception and in constructing the bodily self. Body ownership illusion (BOI) in virtual reality (VR) is a widely used paradigm to study body perception. However, existing research has focused mainly on exteroceptive sensory modalities, and studies on interoception and BOI remain scarce. The postulated mechanism of BOI is related to the multisensory integration of information and visuo-tactile or visuo-kinesthetic sensory conflict resolution. In this within-subjects experimental study, we introduced systematic visuo-interoceptive (visuo-respiratory) conflicts and tested if participants would resolve them by adjusting their respiration rate (RR). Participants observed a virtual breathing avatar body from the first-person perspective while their own RR was recorded. The VR system was connected to a respiration monitor. The avatar was first breathing for 60 seconds in accordance with the participant's RR; then, it was either slowing down or speeding up, each condition lasting for 180 seconds. The dependent variable was changed in participants' RR, expressed as a linear regression slope coefficient. Forty participants were included in each experimental condition, in a counterbalanced order. There was a change in RR in the predicted direction in both conditions. Participants' RR decreased on average by 0.48 breaths/minute and increased by 0.64 breaths/minute, leading to a change of 1.45 and 1.93 breaths/minute, respectively, over the entire timespan of the experiment. The difference between conditions was statistically significant (V = 192, p < 0.01). Because a change in RR of even 1 breath/minute is considered clinically significant, the results of this study-apart from demonstrating visuo-respiratory conflict resolution-may have an applied significance.