Virtual Reality Therapy in the Metaverse: Merging VR for the Outside with VR for the Inside

The Metaverse can be defined as a hybrid (digital/physical) environment offering places for rich user interaction. In this view, the main feature of the Metaverse is a twofold link between the virtual and physical worlds: (a) behavior in the physical world influences the experience in the virtual one and, (b) behavior in the virtual world influences the experience in the real one. Furthermore, any change in the physical world is mirrored in its digital representation (the digital twin), and feedback is sent in the opposite direction (i.e., if the avatar is touched, haptic feedback is provided to the physical body). Currently, this is achieved through 3D shared XR worlds, biosensors and activity sensors (from the real to the virtual world), two-way Internet of Things (IoT) object connections, social media, and wearable devices including smartphones (from the virtual world to the real one). Our view is that bridging technologies that simulate both the external world and the internal world (our bodily experience) will allow the simulated, cognitive, and embodied dimension of the Metaverse to merge, thereby transforming it into the ultimate clinical technology. In particular, it will allow for the emergence of Regenerative VR: the integration of external and internal simulated technologies to rewrite a faulty bodily experience and to regenerate the wellbeing of an individual.