Feeling Present in Virtual Environments

We compare and contrast different current theoretical accounts of telepresence, including presence as a pretence (a simulation of reality), as pretending (making believe the virtual world is real), as a perceptual illusion (“the illusion of non-mediation”), and as embodied attention to the surrounding (or apparently surrounding) environment. These views are well-accepted in the ﬁeld, and can be seen as contributing to a virtual travel experience, which is a kind of illusion. When we feel highly present, we believe in the perceived world in which we experience ourselves to be—it is in that moment real to us. Creating that effect is a key part of a convincing digital travel experience. To have that experience, we must be attending to the digital world, feeling as if we are physically surrounded by it. Our imaginations are involved in how we perceive our surroundings, and in how we conceptualise being there.


Introduction
In Chapter 2 we reviewed perspectives on how we can perceive ourselves to be present in the world. For digital travel to be possible, it is necessary to feel present in another place. That is, to feel present in a different place, real or fictional, that is not the place in which the observer is physically located. This is a place that is perceived as being present but is a product of, or in some way mediated by, digital technology. In this chapter the main focus is on this experience of being present in another place, experienced presence, particularly through the medium of interactive technologies, which is termed telepresence or mediated presence (we use these two terms synonymously). We see presence-the sense of being present-as a general human faculty to experience being somewhere, in a particular place, and telepresence as presence elicited via digital technology. We explore several different views on the nature of presence and telepresence, and the factors that may affect the digital traveller's experience of apparently being in another place, one that he is visiting.
First, we can raise the question: what's the main difference between physical travel and digital travel? In both, the pre-departure stage of any journey might be very similar, and most likely mediated by digital technology; searching for places to visit, things to see and so on. And after the event, recollecting, looking at images, telling people about memories of the trip are also quite similar-and in both cases is likely to be at least partly digitally mediated. The story or narrative through which the traveller plans and makes sense of the journey may be very similar in many respects. What is most obviously different between the two is that with digital travel, the traveller's body can be seen as being left behind. The body is located in a different place from the destination in which the traveller feels herself to be-it remains at home.
Digital travel is an experience of being at a distance (from the place the body is actually located) a form of telepresence or mediated presence. It feels as if the body, by virtue of which the perceiver experiences the world, travels. But, in actuality, the physical body remains at home. Telepresence is thus a paradoxical state for the perceiver. The word has two parts. Tele is the Greek word for at a distance and presence is about the subjective here and now experience. Sometimes the word presence is used as a short form of telepresence, sometimes to refer more generally to the subjective here and now experience. Telepresence implies the use of technology, and is sometimes referred to as mediated, computer-mediated or technologymediated presence.
During the last three decades, many researchers have been interested in telepresence. This is partly due to technological developments, in particular the gaming technology and the role that games play in our society. In computer games there has been significant technological advancement in recent years, in particular in photo-realistic computer graphics. As a result, interactive technology can be used to create virtual environments that look very much like the external world in which we live; in fact, we might not always be able to see the difference. Social presence refers to the salience of people other than the observer in an interaction in a virtual environment and is an important aspect of being in a place. For example, tourists do not only have a spatial experience of place with buildings, nature and attractions-they meet other visitors and residents. Tourists also interact in host-guest relations; that is, with employees of hospitality and tourism facilities, and other people that they meet there.
A video game context can enable the perception of action in another place when watching images on a screen while sitting in a chair. Another example might be a website for a destination developed for marketing purposes. In this marketing context we can ask: what is the effect of this website on the user? An interview may reveal that one user of the website just considers the portrayed destination to be beautiful, while another person who looks at the same website decides it is time to book accommodation, find out how to get there and search for events and what to do upon arrival. The second example corresponds to the notion of perceptible affordance that we revisit later. The question is: How do we operationalise affordance in this kind of context? We return to this question in Chapter 5, where we present empirical findings related to virtual tourism.
The origin of the term "virtual reality" can be traced back to Antonin Artaud and his seminal book The Theatre and Its Double (1938), Artaud described theatre as "la réalité virtuelle", a virtual reality "in which characters, objects, and images take on the phantasmagoric force of alchemy's visionary internal dramas ". It has become common to see the two words virtual and real in the same sentence. Often the message is that Virtual Reality (VR) is different from real or it is the opposite of real. In most cases there is no discussion on what it is meant by real. Schloerb (1995) proposed that perfect telepresence occurs when the observer cannot discriminate virtual from "actual". Deleuze (1994: 208) writes "the virtual is opposed not to the real but to the actual ". The computer graphics could be accurate; that is, what the person sees corresponds to how the place is in the material world when one visits the place. Still, some will argue that it is computer graphics or VR and therefore not real. Schloerb (1995) and then Lee (2004) suggest that sometimes it is more appropriate to use the term actual instead of real. Another term that can be used is face-to-face. This indicates that there is no technology involved; no screen, images or communication through a medium. To Schudson (1978) the unmediated conversation is the ideal fully interactive experience. In many cases face-to-face may be an even more fitting term than actual or real. In particular this is appropriate when we use ordinary language (Etzioni & Etzioni, 1999).
Some installations or apparatus can be regarded as forerunners of today's VR-technology, and were made to create a telepresence experience. In 1420 the Venetian engineer Giovanni Fontana designed castellum umbrarum, a castle of shadows (see Fig. 3.1). Codognet (2003) describes this apparatus as a pre-cave installation and probably one of the first known examples of VR. It has a room with walls composed of folded screens and lighted from behind. What the person in the room sees is moving images that convey a sense of being in a different place. Today the term telepresence is used to describe the use of technology that allows a person to feel as if he or she is present at a place other than the physical location. According to Marvin Minsky (1980), Patrick Gunkel coined the term in 1979 to refer to tele-operation technology that provides the user with a remote presence in a different physical location via displays and feedback systems. But the concept of telepresence is actually older and more general, referring to a feeling of presence via any kind of digital medium, but did not emerge as a research field until the 1990s.

Conceptualisations of Telepresence:
Being Present at a Distance In this section, we focus on a few different views of telepresence, which can help in furthering our understanding of the nature of digital travel.

The Illusion of non-Mediation
Perhaps the most highly cited definition of presence is by Lombard and Ditton (1997). They conceptualise telepresence as a kind of illusion, the perceptual illusion of non-mediation. This implies that they regard telepresence as a property of a person. It results from an interaction between formal and content characteristics of a medium and characteristics of the media user, and therefore it can and does vary across individuals and across time for the same individual. However, they do not explain or discuss the use of the term "illusion", which can have more than one interpretation. In the same vein, to Riva (1999: 91) "the key issue for developing satisfying virtual environments is measuring the disappearance of mediation ( our emphasis), a level of experience where the VR system and the physical environment disappear from the user's phenomenal awareness ". This is an almost ubiquitous and very influential view of presence, resonating with the blind man's cane example of Merleau-Ponty (1962) and the notion of transparency discussed in Chapter 2. The blind man walks down the street, exploring the world with his cane. He is not primarily aware of the cane, but of what he perceives with its active use. In the context of telepresence and mediated presence, the medium (the display and the input devices) correspond to the cane. The VR technology disappears for the perceiver, and becomes part of the here-body experience (Ihde, 2002). Lombard and Ditton's (1997) description of presence is appealing and well-accepted, but has some limitations. It is essentially a formulation of presence as "being there", at least perceptually. We perceive we are in a place without being distracted by the mediating technology, which has become transparent. But is this sufficient for the presence experience? Is it an illusion, or simply that the perceiver doesn´t notice the medium?

Pretending the Digital Is Physical
Turner and his colleagues have argued for the importance believing has for real-world presence but for the importance of pretending (to believe) or make-believing, for computer-mediated presence. For example, Turner et al. (2014: 1) suggest that: "A principal, but largely unexplored, use of our cognition when using interacting technology involves pretending. To pretend is to believe that which is not the case, for example, when we use the desktop on our personal computer we are pretending, that is, we are pretending that the screen is a desktop upon which windows reside. But, of course, the screen really isn't a desktop". Turner et al. (2014) states that when we play a computer game "we temporarily believe that we are killing aliens ". He suggests that at some reflective level we know we are not killing aliens, but we have the vivid experience that we are, thanks to the game technology and media content. This seems to be another formulation of presence seen as the experiential illusion of non-mediation, but is not what is commonly understood by pretending. On the contrary, pretending seems to be characterised by not believing, not by the temporary belief that a mediated experience is real.
While belief does seem to play a role in presence for both the physical world and computer-mediated environment, we suggest it is not a prerequisite, but a consequence, of presence. The old saying "seeing is believing" can be rephrased as presence is believing. Following Spinoza, as discussed in Chapter 2, we can say that when we feel present in a world, it is real for us in that moment. We believe it to be the case in the here and now of experience, without pretending to.
When we feel presence, we may know (at some level) that the experience is not based on the body being where it is felt to be, but we do not need to pretend to experience this as real. But people vary in terms of how willing they are to have this experience in a digital environment. User characteristics, such as expressed willingness to experience presence in a VE, affect the level of presence reported (e.g. Cummings & Bailenson, 2016;Sas & O'Hare, 2003). Turner et al. (2014) argues for presence as make-believe from a type-2 cognitive process point of view (see our discussion of dual process theory in Chapter 2), the result of relatively slow and deliberative thinking. But this contradicts the idea that presence arises in situations where fast and instinctive bodily responses (from a type-1 cognitive process) are called for, for example, in a fast-paced computer game. As Waterworth and Riva (2014: 38) describe presence as "the sheer subjective experience of being in a given environment (the feeling of 'being there') that is the product of an intuitive experience-based metacognitive judgment".

Experiencing a Convincing Simulated Semblance (of Physical Reality)
By this view, presence in a VR results when the simulation elicits similar reactions in an observer to the corresponding place in the physical world (Slater, 2003). Presence is "the total response to being in a place, and to being in a place with other people". (Slater, 2002, p. 7). Slater (2009) suggests that presence in VR is "the extent to which people respond realistically within a virtual environment, where response is taken at every level from low-level physiological to high-level emotional and behavioural responses" (p. 3555). Slater further suggests that this depends on two illusions, the "place illusion" (PI) and the "plausibility illusion" (Psi). He says that: "If you are there (PI) and what appears to be happening is really happening (Psi), then this is happening to you! Hence you are likely to respond as if it were real" (p. 3555). The key phrase here is "is really happening".
One is unlikely to feel much presence in a poorly rendered VR, a lowquality simulation of reality, with unrealistic sound and a perceptible lag between actions and the corresponding events in the virtual world. In the physical world, the form is to a large extent given, and things behave and respond according to our embodied and largely unconscious expectations. Any measure of presence in a VR is only useful, according to this approach, when compared to results of the same measure taken in a physical situation. The more similar the reaction in the VR is to that in the physical world, the greater the degree of presence.
But if presence is the total response to a simulation, as compared to the total response to the physical environment being simulated, how do we assess presence in virtual environments that convey fictional realities?
If no comparison with reality is involved, how can the "total response" be quantified? This view suggests that presence is the degree of similarity with physical reality, not a basic state of consciousness.
It seems reasonable that if the form of the physical world can be accurately simulated, we will have the same experiences in the mediated world as in the physical one. And we will have the same level of presence. But that does not imply that the level of presence experienced in a virtual environment is the same as the level of accuracy of the simulation, as how well the semblance is executed. We can sometimes feel little presence in the physical world-during a boring lecture, for example. If we accurately simulate that experience in a virtual environment we will also feel little presence. Therefore, presence cannot be purely a matter of experiencing a realistic semblance of a place. But is it an illusion?

Telepresence and Perceptual Illusions
Many accounts of presence see it as resulting from some form of illusion. The concept of illusion is closely related to that of belief. To the best of our knowledge, Turner is the only theorist to discuss belief, which we see this as another key concept for a more general understanding of the characteristics of presence.
There are a number of different accounts of perceptual illusions. The psychologist Osvaldo Da Pos (1996,1997,2008) distinguished between the two kinds. The first are the psychophysical illusions that are discrepancies between what we perceive, for example, redness, and the physical, not perceivable variables, for example, wavelength, which are known to be correlated (Da Pos, 1997: 37). The second are the phenomenological illusions. These are discrepancies within the phenomenal world. When these occur, the same perceived object appears at one time with some characteristics and at another time with different characteristics.
According to Reynolds (1988) the psychological concept of illusion can be defined as a process involving an interaction of logical and empirical considerations. Common usage suggests that an illusion is a discrepancy between one's awareness and some stimulus. (Reynolds, 1988) After proposing and rejecting five definitions of illusion based on this usage, he redefines illusion without reference to truth or falsity, as: "a discrepancy between one's perceptions of an object or event observed under different conditions " (Reynolds, 1988: 217). Byrne (2009) argued that there is no direct path from the persistence of illusion to the belief-independence of experience. To him, the Müller-Lyer illusion (see Fig. 3.2) involves a belief that one line is longer than the other, and another, more reflective belief that they are of the same length. This is relevant to the way presence may work; we may know, reflectively, that what we experience in a VR is not really happening, but our experience is that it is and, in the moment of experiencing, we may actually believe that it is happening. Turner et al. (e.g. 2016) makes the same point, although they equate mediated presence with make-believing, with pretending to believe, rather than actually believing-which reduces the coherence of his position, unless we are pretending to experience an illusion. Turner and colleagues state that make-believe "is a form of cognition which is decoupled from the real world and which enables us to explore and engage with fictional or imaginary worlds" (Turner et al., 2014). Voss et al. (2011) posit the notion of the spectator as surrogate body. The word Leihkörper literally means "loan body". This concept emphasises the basic structure of the illusion that informs the cinematic experience. Voss et al. argue that cinema is an illusion-forming medium and that cinematic illusion emerges from the spectator's engagement with the virtual or loan body of the film. Their thesis is that it is "only the spectator's body, in its mental and sensorial-affective resonance with the events onscreen, which 'loans' a three-dimensional body to the screen and thus flips the second dimension of the film event over into the third dimension of the sensing body" (2011: 145). Voss and her colleagues build on Michael Polanyi's (1966) work on the tacit dimension.
As an example of a perceptual illusion, imagine that you are out late at night, walking alone, taking a short-cut to get home. It is dark and there seems to be no-one else around. Your walk takes you through a particularly secluded area, perhaps a path through some woods, across a park, or down dark and deserted streets. You wanted to get home quickly, so you chose this route. But now you start to feel afraid. You see what looks like the figure of a person in the middle distance, difficult to see clearly in the darkness. You know that you have to walk close to this figure to get home.
As you get closer, you get the clear impression that the person you first saw vaguely from the distance is watching you, and perhaps waiting for you to get nearer. You start to feel afraid and already you feel very present in that environment-much more so than when you first saw "the watcher". You are acutely aware that you have no other way home, except to pass the figure or turn and retrace your steps-which would take a long time (and mean turning your back on the potential danger). You draw closer, ever more convinced that the figure is watching you, and that he or she has a sinister intent.
Still, you press on, heart beating fast and acutely aware of your presence in this place, with this person. Suddenly, as you get quite close to the figure, you realise that it is not, in fact, a person at all! It is a misshapen, sawn-off tree trunk and empty crate, with an old paper sack that has somehow come to be attached to the top. You relax, you walk on breathing more deeply and calmly, laughing at your own mistake, which you replay in your mind. You will tell your friends about this funny episode when you get home. You no longer feel afraid, or very present in the place.
This story of the sinister watcher, who wasn't actually there, illustrates how we can readily misperceive our environment, seeing it in different ways at different times, and that this can have profound effect on our sense of presence, of being there. In this example, high presence results from a misperception that can be understood as an illusion. But that is not to say that presence is always an illusion, it could equally be the case that the presence-inducing perception turned out to be the true one.
Perception (and presence) is partly a matter of hypothesis generation and testing. When we are fearful we tend to see what our fear predicts-as in the case of policemen mistaking a mobile phone, held by a black suspect on a dark street, for a gun. The constructivist theory of Gregory (1970) emphasised the importance of top-down processing to perception. While his view seems exaggerated in light of the clear importance of sensory information to much of perception, when that information is ambiguous our cognition appears to generate hypotheses about what might be out there to guide the perceptual process. According to our three-layer model of presence in the physical world (see Sect. 4.2, above), this corresponds to the functioning of extended presence. Top-down processing is sometimes important-but it also results in misperceptions. Gregory (1970) used it convincingly to explain how several perceptual illusions work, including the ambiguous Necker cube (Necker, 1832) shown in Fig. 3.1.

Perception, Imagination and Attention
Presence depends on perception, and here we see the importance of imagination, of top-down processing. In imagination we use metaphorical projection to make sense of what we are perceiving. But metaphor does not imply the use of imagination. Rather, imagination implies the use of metaphor, so that perception-and presence-often involves the use of metaphor. This leads us to the conclusion that our experience of any world-physical or digital-is metaphorical, in the sense that we project embodied image schemata (Johnson, 1987;Lakoff, 1987;Lakoff & Johnson, 1988) onto what we pick up as sensations to make sense of them as perceptions. When these sensations are generated or stimulated via an electronic medium, they can trigger the experience of being in another place, of a digital visit somewhere.
The top-down approach to perception of Gregory (1970) is often contrasted with the more bottom-up approach of Gibson (1966Gibson ( , 1972. According to Gibson, perception is largely "built-in". How we perceive things is driven, bottom-up, by innate structures. Gibson sees how we perceive as having developed over the course of evolution, and this is how we see our capacity for varying levels of presence experience. We resolve this apparent contradiction by viewing the innate structures of perception (Gibson, 1972) as another way of viewing the image schemata of Lakoff and Johnson (Johnson, 1987;Lakoff, 1987;Lakoff & Johnson, 1988). Both reflect universal human structures of meaning in experience, in imagination and through perception, reflecting the sense-data view and representationalism discussed in Chapter 2.

Presence as the Feeling of Attending to a Surrounding External World
How do we distinguish perceptions of the external world (perceptions which may themselves be largely hypothetical mental predictions) from the purely mental constructions that constitute imagined situations and events? In other words, how do we separate the internally realised world from the externally realised world? We see presence as the capacity to make this distinction and which helps us survive in a dangerous world. This is the purpose of presence (see Waterworth et al., 2015, for more details). Waterworth et al. (2015: 36 and 48;2020: 74) define presence as "the feeling of being located in a perceptible external world around the self", and "Varying feelings of presence reflect the extent to which attention is focused on the external environment". Presence is an experience of being in a place, one that allows us to separate the self from the nonself, the internal from the external, a faculty that helps us to survive. From this perspective, an external world-whether mediated or notwill give rise to a sense of presence, of being present in that world, in direct proportion to the extent to which the individual pays attention to that world. As Slater (2003) pointed out, presence should be distinguished from emotional engagement, but emotional engagement has an impact on presence, through its effect on level of arousal and attentional selection.
Attention to the external is important to presence in the physical world, and it is similarly important for presence in mediated worlds. We also need to believe in what is happening in a world, whether physical or not. In a mediated world, we need to provide a convincing pretence of reality for presence. But we need to attend to that pretence, and we need a reason to believe that drives our attention. We are not pretending, except in the sense that, at some level, we know the virtual reality is a simulation. But in the moment, it is real. In the moment we see the sinister watcher, we believe he is real. A moment later, we don't. This is equally true in a VR as in the physical world. Presence can be viewed as sometimes resulting from a perceptual illusion. We need to attend for an illusion to work, but only to the things that make it work. Perception can itself sometimes be illusory, in so much as we perceive something that is not as we perceive it to be.
When we feel present, we believe that what is happening is real, whether in the physical world or a VR. We do not pretend to believe, and we do not make-believe as Turner suggests. Pretence is what we do when we pay attention to fictional things, and real things too-that we know (believe) are not what we are currently perceiving in the world around our body. The form of the physical world is given, but ambiguous. In VR, we can experience fictional worlds as if they are real-in fact, as real in the moment. We believe in them and do not need to pretend that we do. Believing in the real, in-the-moment existence of something, experienced as being before us, is a characteristic of perception (and hallucinations;Smith, 2002Smith, , 2010 and of presence.

Interacting with Other People
Our discussion so far has focused mainly on the individual's experience of spatial presence, the feeling of being there in an environment, for instance, a physical place, other than the one in which the body is physically located. Wirth et al. (2007: 497) out this as follows: "Spatial Presence is …the sensation of being physically situated within the spatial environment portrayed by the medium ("self-location")". According to Sanchez-Vives and Slater (2005) the concept of spatial presence has had an impact on our understanding of human cognition and consciousness. Spatial presence involves perceptions of perceptually real environments, while social presence involves perceptions of social interactions with persons, places or things (Reno, 2005). Both are important in digital travel. Social presence, as the sense of being together with another, involves factors such as primitive responses to social cues, simulations of other minds, and automatically generated models of the intentionality of the other (Biocca et al., 2003, p. 459).
Social presence is the degree of salience or awareness of other persons in an interaction in, for instance, a virtual environment. It is the process by which people feel that they are in the presence of other people. Heeter (1992) defined it as the sense of "being with others ". We can use tourists as an example. Tourists do not only have a spatial experience of place with buildings, nature and attractions, they often also meet other visitors and residents of a place. Tourists specifically interact in host-guest relations; that is, with employees of hospitality and tourism facilities, and also with people that they meet living or visiting there. Horton and Wohl (1956) coined the term para-social interaction as a label for TV viewers' responses to people on the screen. According to Horton and Wohl (1956: 32): "One of the striking characteristics of the new mass media -radio, television, and the movies -is that they give the illusion of face-to-face relationship with the performer. The conditions of response to the performer are analogous to those in a primary group". Para-social interaction is related to social presence. Kumar and Benbasat (2002) defined para-social presence as the extent to which a medium facilitates a sense of understanding, connection, involvement and interaction among participating social entities. Giles (2002) argues that there is a correlation between para-social interaction and face-to-face interaction, but para-social interaction inevitably takes place across a distance and is entirely constrained by social and communicative conventions.
Mirrors are not only used for seeing oneself but for seeing others. To Umberto Eco (2000) TV, and in particular live broadcast, has similarities with the mirror experience. Real-time TV and mirrors are prostheses of human perception because they show things in a state of presence (Eco, 2000;Soffner, 2006). Short, Williams and Christie (1976) developed the ideas of what they called Social Presence Theory (SPT) in the context of telecommunications. SPT is the degree to which a person is perceived to be a "real person" in their computer-mediated communication or virtual environments. Or, put another way, it describes the ability of communication media to transmit social cues. The level of social presence influences the quality of virtual interactions and outcomes. London & Hall (2011), Roberts and Sambrook (2014), Li and Wang (2013), Wu and Zhang (2014), Evans (2014Evans ( , 2019 and Anderson et al. (2020) suggested that social networks and Web 2.0 tools could increase social presence in virtual business communications. The extent to which communication in a virtual environment can convey social presence will profoundly affect the quality of the digital travel experience, and the felt proximity wit people and places visited digitally.

Activities in Place: The Role of Affordances
In chapter 2 we reviewed enactivism, the view that holds that sensorimotor skills are constitutive for perception and that experiences are inseparable from the perceiver's bodily activities. In this section the focus is on the role of activity in telepresence. Flach and Holden (1998) were among the first scholars to investigate affordance in the context of presence, by emphasising the necessity to understand the effect of interaction with objects in virtual environments. With reference to Gibson's theory, they write about virtual reality (1998: 94): "From this perspective it is the dynamic interplay between visual, acoustic, and tactile feedback and the actions of looking around and manipulating objects that determines the fidelity of a simulation…(and)… in virtual environments the constraints on action take precedence over the constraints on perception".
Why do participants tend to respond realistically to situations and events portrayed within an immersive VR system? Slater (2009a) asks this question and distinguishes between immersive and non-immersive systems, arguing that in an ideal immersive system it is possible to fully simulate normal actions in physical reality. He does not use or refer to the term affordance in this paper, but what he calls correlation presence, which is the correlation(s) between activities and sensory feedback. According to Slater et al. (2009b): "it seems that humans have a propensity to find correlations between their activity and internal state and their sense perceptions of what is going on 'out there'".
Presence does not demand high fidelity to physical reality, but rather that people do respond, and are able to respond, as if the sensory data transmitted by a medium were physically real. When aspects of our sensory data are being generated by a virtual reality, the perceptual system operates in exactly the same way as in an unmediated situation. The two terms, correlational presence and affordance, are closely related; the affordances offered by a virtual environment trigger and should support correlation presence (Sanchez-Vives & Slater, 2005).
Gibson, a perceptual psychologist, introduced the term affordance in his book, The Ecological Approach to Visual Perception (1979). His motivation was to complete the ecological theory of direct perception (Dotov et al., 2012). Since then the affordance concept has been used in a number of disciplines other than psychology, notably human-computer interaction (Hartson, 2003;Norman, 1999). Gibson claimed that we perceive objects as having properties of what we ought to do with them and attributes full normativity to affordances. Affordances are not properties of what we should do with an object, but what we can do with it. User interfaces can offer perceptible affordances (Gaver, 1991), since they can offer information about virtual objects that can be acted upon. A perceptible affordance is a perceptual cue to the function of an object that causes an action. For instance, a visual presentation contains visual information about the behavioural possibilities afforded to the user. It is this action and behavioural aspect that the affordance concept captures.
In tourism, sightseeing is a common activity. A perceptible affordance queries what activity a particular sightseer would like to engage in at a particular moment in time. There are a number of actions that can provide perceptible affordance in sightseeing when it takes place in a VE. Consider viewing an attraction on the screen, for instance, a tourist who gazes at an historic monument and at that moment thinks, "I will walk to the front door and enter the building through that door". According to Morie et al. (2005) all affordances are user contingent; in a VE they are essentially triggers that might result in an action (physical response) or a reaction (emotional response) from the participant. Sensory data play a key role.
A video game context can simultaneously enable the perception of action, when watching images on a screen while sitting passively in a chair. Another example might be a website for a destination developed for marketing purposes. In this marketing context we can ask: what is the effect of this website on the user? An interview may reveal that one user of the website considers the portrayed destination to be beautiful, while another person who looks at the same website decides it is time to book accommodation, find out how to get there, and search for events and what to do upon arrival. It is this second example that corresponds to the notion of perceptible affordance. In both cases, the notion of transparency discussed above, of not noticing the technology producing the experience, is a key part of the affordance-action loop.
But how do we operationalise affordance? Few empirical studies have operationalised affordance in a VR context. One example from an ecommerce study is Algharabat and Dennis (2010) who operationalise virtual affordance as follows: "3D let me feel like as if I am holding a real laptop and rotating it ". In Chapter 5 we present two experimental studies which, among other factors, looked closely at the importance of affordances in a digital tourism context. Additionally, we present new findings on the view people have of the possibilities and desirability of digital travel, gathered by survey during the COVID-19 pandemic with the attendant hazards and restrictions on physical travel.

Implications For Digital Travel
Telepresence is the experience of being somewhere other than one's physical location, and can be achieved through digital media, perhaps only through digital media. It is tantamount to experiencing a sense of place through digital technology. The main focus of the chapter was thus to compare and contrast different current theoretical accounts of telepresence, in the light of their plausibility and implications for understanding in what ways people can experience a sense of being in a place other than their physical location, and with other people. These accounts included presence as a pretence (a simulation of reality), as pretending (making believe the virtual world is real), as a perceptual illusion ("the illusion of non-mediation") and as embodied attention to the surrounding (or apparently surrounding) environment. These views are all well-accepted in the field, and all can be seen as contributing to a virtual travel experience, which is itself a kind of illusion.
Our argument was informed by the Spinozian model of rapid acceptance response introduced in Chapter 2-we initially believe (accept as real) any argument (experience) that we can understand, then may reassess and reach a more settled judgment once the moment has passed. In line with this, as we saw in Chapter 2, presence itself is seen as a Type-1, an intuitive, perceptual process. But digital travel is more than just feeling present in a mediated environment, in the moment.
Travel is usually planned and is always reflected upon after the event. During a trip, and while making a visit, our expectations and earlier reflections will influence the nature of the experience, as will our meetings with people and the activities we engage in. Afterwards, we will reflect further, telling ourselves and others about our experiences. What we remember will be to some extent a function of how present we feel in a place, whether the place is physical or digitally created-this is a key aspect of the power of presence and its significance for digital travel.
When we feel highly present, we believe in the perceived world in which we experience ourselves to be. In that moment it is real to us. Creating that effect is a key part of a convincing digital travel experience. To have that experience, we must be attending to the digital world, feeling as if we are (as-if-physically) surrounded by it. When that is achieved, our imaginations are involved in at least two ways: in how we perceive our surroundings, and in how we conceptualise our being there. While we do not think that we need to make-believe (that the world is real), we do use our imagination, and memory, to make sense of what happens there. The world may be a simulation, be veridical, be misperceived or even be an hallucination. In the moment we do not reflect on this question, and so we do not know which it is-but we believe that it is. And when we later reflect and talk about our experience, it is as if it were real-which, to us, it was.