Virtual Reailty
UNESCO Arts, Science & Technology

PRESENCE within Virtual Reailty

Virtual reality (VR) is a human-computer interface which allows a user to take advantage of natural human abilities when interacting with an artificial, computed environment. The ultimate goal of VR is to produce a transparent link from human to machine, a user interface through which information is passed so naturally between user and environment that the user achieves a complete sense of presence within the computer- generated simulation, or "virtual world."

Presence can be defined as the sense of "being there" or being immersed in a VR simulation. This illusion or sense can be particularly strong in some virtual worlds. Users, for example, may feel as though they are flying, or may feel vertigo when looking down a deep canyon. Users may also feel as though they can touch a computer-generated object that responds. It is thought that the sense of presence in VR can be particularly strong because in this medium, a user's senses are involved in direct feedback loop with the simulation -- when a user moves, the simulation immediately responds. The sense of presence is one reason that VR is successfully used to treat patients who suffer from a fear of heights, or treat the pain suffered by burn victims.

Telepresence refers to the sense not only of being in a VR simulation, but additionally involves remote environments and other users who are geographically distant. In artist Margaret Dolinsky's Beat Box, for instance, users at 5 different locations were all "telepresent" in a common computer simulation, playing computed musical instruments. Similarly, students in a real-time simulation can remotely control an underwater vehicle that can pick up physical rocks on the ocean floor.

Philosophically, presence raises questions that problematize our notions of what is real. How do we verify reality? Is the sense of "being there" in a virtual world fundamentally different than the sense of being in real space? Does more sensory engagement than what is possible when looking at a painting, for example, result in a greater sense of presence? Fears about confusing a virtual world with the physical world have long been the subject of science fiction. However, VR makes such concerns more immediate because of phenomena like "simulator sickness" and by the perceptual after effects of being in a simulation. For instance, pilots who are trained in flight simulators must avoid driving cars for a time so their perceptions can readjust to the physical world.

Critical theory would suggest that the physical world is as much aconstruction of mind (for example, the role of gender in perception) as the world constructed from computer simulations. The history of the arts would further suggest that being in another world is not simply just a sending of sensual cues as many engineers would like to imagine. Images are not that interchangeable from medium to medium to the same affect. An artist is practiced in how subtleties and nuances within a given medium may achieve a richer sense of presence than one created by someone who lacks this specific type of knowledge.

Artists and scientists are increasingly interested in the issue of presence. What kinds of environments can they create to allow users to confront the questions and meanings of presence? These questions become more critical as the richness of simulations become greater and the ability to act at a distance is augmented through expanding forms of new technologies.