## 3 The Ambiguity of Virtual Reality Terminology in Healthcare and Beyond
### Rethinking the Meaning of Virtual Reality: A Proposed Framework
However, since the technology used in these environments does not allow for complete visual detachment from the real world, we categorize them as non-immersive environments. We would like to emphasize that this distinction is not based on differences in the effectiveness of non-immersive and immersive environments. The separation of non-immersive environments is made based on the technological solutions these environments offer compared to immersive ones. As presented in the review article by [PERSON] et al., (2021) [69] immersion is described as \"_a more objective quality of VR_\" and \"_the technical qualities of a system_\". Furthermore, this distinction aligns with certain proposals from other authors in the field who also define VR as exclusively immersive environments [47; 49; 50]. This separation is not intended to discourage the use of non-immersive environments in healthcare but rather to establish a clear and standardized framework for understanding and categorizing VR technologies based on their technical characteristics. Proposition 2 is illustrated in Figure 3.  
**Proposition 3**: _VR should be divided into two continua of immersion depth based on exteroceptive and interoceptive system involvement._  
The level of immersion in VR should be categorized based on the involvement of the exteroceptive system (i.e., sensory signals from outside the body) and the interoceptive system (i.e., sensory signals from inside the body). Such a classification has likely not been introduced previously due to the limited research on interoceptive system stimulation until recent years. However, evidence in this field is growing. For instance, [PERSON] et al., (2023) [79] demonstrated the ability to artificially manipulate interoceptive cortical signaling using a non-invasive stimulation technique called Sonoception. They showed that auditory synthetic stimulation (Sonoception) could prime insular activity (a key component of the interoceptive system that processes and integrates signals from within the body), either enhancing impulsivity or promoting inhibitory control, depending on the specific area of the insula targeted. Other interoceptive technologies are also emerging in research. These include methods that produce direct modulation of interoceptive signals, such as C-fiber stimulation [80; 81], as well as tools that create illusions by providing individuals with false feedback about their physiological states [82]. To the best of our knowledge, no research in the healthcare field has yet combined VR with interception stimulation. However, there are articles that discuss the integration of internal body stimulation with VR in the medical field [83], highlighting the need to reconceptualize certain previous frameworks that suggested interception stimulation with modern technology was not possible [42]. **Proposition 4**: _Immersion should be categorized based on the number of stimulated senses and the quality of virtual stimulation._  
We propose that the level of immersion should be categorized based on the number of senses stimulated and the quality of virtual stimulation. In the case of exteroception, it is possible to virtually stimulate all senses quantitatively, making this continuum continuous. In contrast, the immersion of the interoceptive system is inherently limited, as technology cannot fully simulate all interoceptive signals. A higher number of stimulated senses enhances immersion and, consequently, the sense of presence by increasing the feeling of \"being there\" [84]. This occurs because more attentional resources are allocated to the virtual world as the number of stimulated senses increases [84]. The level of immersion  
Figure 3: Our proposal for naming environments currently defined as “non-immersive VR”. We propose that such environments be referred to as “_non-immersive fully artificial environments_”.