Breathing training guided by an embodied agent in immersive virtual reality: a study of psychological and physiological effects

Slow deep breathing (SDB) techniques offer physical and mental health benefits that help mitigate stress, anxiety, and pain. However, economic and logistical barriers limit access to traditional breathing training programs. While self-help resources like videos and apps are available, they lack the personalized guidance and feedback provided by human trainers and tend to have high dropout rates. The increasing availability of consumer-grade virtual reality (VR) headsets presents new opportunities for immersive breathing training experiences guided by embodied agents, potentially enhancing engagement and adherence. While immersive VR (iVR) has shown benefits for relaxation, much of the existing research has not focused on using an embodied agent as a coach for SDB training, leaving unclear whether this approach can benefit from iVR. This paper addresses this question by comparing agent-guided SDB training in iVR (headset-based) vs. non-immersive VR (based on a computer monitor). We introduce and evaluate an embodied agent that provides users with real-time, personalized feedback on their respiratory frequency and depth. We evaluate both self-reported measures (including engagement, attention, presence, and perception of the embodied agent) and objective physiological signals, comprising respiration, electrodermal activity, cardiac activity, and brain prefrontal cortex activity (acquired through functional near-infrared spectroscopy, fNIRS). Results highlight several benefits of iVR over non-immersive VR. They showed that iVR increased users’ attention, engagement, sense of presence, social presence, and perceived anthropomorphism of the embodied agent compared to non-immersive VR. Physiologically, iVR improved depth of breathing at the target SDB frequency, enhanced cardiorespiratory coupling, and decreased sympathetic arousal. The study included an evaluation of a secondary, smaller personalization technique (name personalization: the embodied agent could or could not address participants by name), which did not yield any significant result. The paper describes and discusses these findings, highlighting the important role that iVR could play in enhancing the effectiveness of breathing training.