The sense of presence is part of human evolution
Riva, Waterworth and Waterworth were inspired by Damasio in their proposal for a deeper understanding of Presence. After having studied Damasio's work they suggest that presence is the feeling that has developed in evolution to help people distinguish between 'real' and 'unreal' situations: "In its earliest evolutionary form, presence was the sense that something was happening outside the organism in the here and now, something that could affect the organism, as opposed to being part of the organism. Initially, this may have been based in the sensation (in proto consciousness) of something acting on the organism's boundary with the environment. Later, in evolutionary (and neurological) terms, sensation led to perception and presence emerged as the feeling (in core consciousness) of being in an external, perceptible world in which things happen in relation to the organism. Later still, internal modelling (in extended consciousness) allowed attention to be directed towards non-present, imagined worlds, experienced as being inside the organism (specifically in the head). To be useful in assessing possible scenarios, presumably their main evolutionary purpose, the imagined events that were used evoked similar emotional responses to those that external events would, but not the same feeling of presence." (Riva, Waterworth & Waterworth 2004, 417).
The view that Riva, Waterworth and Waterworth present on how the feeling of presence is a phenomenon that helps us survive, triggers a variety of questions when we realize that technological development is driving towards a creation of feeling-of-presence, which can not be distinguished from 'real' presence. For our survival we need to be able to distinguish between real and unreal. This is exactly why we developed this feeling of presence in evolution, to be able to distinguish between imaginary worlds and the 'real' world as Riva, Waterworth and Waterworth convincingly argue.