Presence

Presence has been an important concept for philosophers as early as Plato and as recent as Heidegger and Derrida. For computer researchers working on VR, the term gained currency with the appearance of the journal Presence in 1992. Just as photorealism had been the goal of computer graphics, presence became the goal of VR. The ideal VR system would lead the user to feel that she was actually in a CG world. The VR world would become her reality, but no current VR can deceive its users so completely. A feeling of presence is always accompanied by some residual or recurring awareness of technology. The La Ciotat myth always gives way to the LaCiotat effect.

Computer specialists have offered a variety of definitions of presence, including:

• transportation: the feeling of being taken to another place/world;
• immersion: the feeling of being surrounded by a virtual world;
• realism: the sense of reality conveyed by the represented world;
• social richness: for multi-person experiences, the sense of being together with others.

We provide examples in the first room of the gallery.

In the second room, there are examples of the effects of presence. There is a portal to a 3D Pit used in an experiment conducted by researchers at the University of North Carolina. In this experiment researchers tried to evoke a fear of heights in test subjects by having them walk close to and peer over the edge of a virtual pit. They then measured the subjects' physiological reactions, such as heart rate and skin conductance. In framing this experiment, the researchers were implicitly arguing that physical fear was evidence of presence (a version of the "realism" definition). One thing that experiment suggested is that fully deceiving the user is not necessary for a sense of presence. Full photorealistic immersion in the pit experiment was not possible, but subjects still reacted to the pit. (But perhaps their physical reaction was inspired by wonder as much as fear?)

Artists Chris Milk and Nonny de la Peña a different understanding of presence in their respective work displayed in the second room of the gallery. In 2015, two filmmakers, Chris Milk and Gabo Arora, created a 360-degree video called Clouds over Sidra (Arora and Milk 2015), produced with the support of the United Nations in an effort to raise awareness of the Syrian refugee crisis. In a TED talk Milk called VR an empathy machine. Milk said of Sidra: “When you’re inside of the headset . . . you see full 360 degrees, in all directions. And when you’re sitting there in her room, watching [the girl Sidra], you’re not watching it through a television screen, you’re not watching it through a window, you’re sitting there with her." Nonny de la Peña's work with VR as a medium for politically motivated journalism: to evoke empathy for prisoners in Guantanemo or the homeless in Los Angeles.

A third and very different manifestation of presence is cybersickness——visually induced motion sickness that many users feel when they wear a VR headset and, for example, take a ride on a virtual roller coaster. Cybersickness both affirms and denies presence at the same time. The nauseating sensation produced by the roller coaster is physiological evidence is presense through transportation. On the other hand, it becomes difficult to continue with the experience. Cybersickness reminds the user of the medium in a powerful way, when nausea replaces astonishment.

Aura

The third room is devoted to aura, a special kind of presence. The term comes from the media scholar Walter Benjamin, writing in the 1930s, long before digital media. He argued that the media technologies of his day, film and photography, diminished the aura of earlier media, such as painting. You can only experience da Vinci's Mona Lisa in the Louvre in Paris. There is only one authentic painting. But you can experience what is essentially the same movie (say a film by Charlie Chaplin) anywhere, by watching any good copy. We can bring Benjamin’s concept into the present and ask about the status of VR and AR. It seems clear that VR generally lacks aura in Benjamin's sense. VR worlds are generally detached from the unique experience of this world. You can have the same VR experience anywhere. But at least some AR experiences are geolocated, linked directly to the places in this world—for example, a 3D recreation of the Parthenon that you can only see if you visit the Acropolis in Athens. AR cultural heritage applications for historic sites can be said to appropriate and perhaps even enhance the aura of the site.

Cybersickness

The physiological responses evoked by VR can confirm a feeling of presence, but they can also erase it. The term cybersickness has been coined to describe symptoms including headache, nausea, eyestrain, dizziness, fatigue, or even vomiting that may occur during or after exposure to a virtual environment. Those symptoms provide visceral evidence that VR is not the medium to end all media. Cybersickness shatters not only the La Ciotat myth, but also the La Ciotat effect.

Enter the Presence Gallery.

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