Well, I finally saw the film Avatar. Throughout the movie, I kept reflecting about virtual reality (VR) and the many different ways that it manifested while I was watching. I'm using the definition of VR as described in the paper, "Virtual Reality: A Survival Guide for the Social Scientist" by Fox, Arena, and Bailensen (2009):
Virtual reality (VR) was originally conceived as a digitally created space that humans could access by donning sophisticated computer equipment (Lanier, 1992; Rheingold, 1991; Sutherland, 1968). Once inside that space, people could be transported to a different world, a substitute reality in which one could interact with objects, people, and environments, the appearance of which were bound only by the limits of the human imagination.
1. The most obvious example of VR was part of the film’s story: Jake, a paraplegic veteran, goes offworld to “link” with a specially grown alien life form (a Na’vi) that was based on his twin brother’s DNA. (His twin brother died and Jake has agreed to take his place; the “linking” is a form of virtual reality, where Jake’s thoughts animate the Na’vi. When Jake is hooked up to the extensive VR machine (see photo), his Na’vi literally embodies all of Jake’s thoughts, feelings and actions.) As Jake spends more time immersed in the life of his Na’vi host, that world feels more real to him than the one his “normal” body inhabits. (With this type of virtual reality, it is not the user's bodily movements that direct the avatar's movement; rather, from what I can tell of the film, it is the user's thoughts--as brain activity--that direct the avatar.)
2. Na’vis have long hair (often in braids) and at the end is a set of tendrils that can intertwine with the tendrils of certain other species on the planet. When the tendrils intertwine, the two life forms temporarily merge—experience what the other is experiencing. So, for instance, when Jake’s tendrils merge with an animal he’s trying to ride, Jake can experience the animal’s breathing, muscles, and other bodily functions, and that animal can experience Jake’s desire to turn left or right. It’s a kind of merged VR, where you experience another being’s reality while also experiencing your own. It's portrayed as an intimate experience. (This VR experience seems to arise through physical contact between the two entities, with the bodily "connectors"--the entwining of two organisms' tendrils--relaying information to create a merged virtual reality.)
3. Some of the film’s bad guys (ex-military personnel working or a corporation) also have VR experiences, but with technology (below), not with another species. Like the Star Wars AT-AT walkers on the ice planet Hoth, the Avatar company men are able to move their walkers by moving their own limbs. Their arm and finger movements are mimicked by their devices. (This method of VR is one that is more familiar in our world; the user's bodily movements lead the avatar--in this case the AT-AT-like device--to move.)
4. Finally there was my own VR experience: Just seeing the film was a virtual reality experience. I saw the film in 3-D (with glasses), and so what I saw on the screen felt more “real” and was a much more immersive experience than the normal experience of watching a film—even one that is very absorbing. And there were previews for three other 3-D films, so this is only the beginning. Okay, so it wasn't an interactive experience, but rather than watching a film, it felt as if I was witnessing the events on the screen--that I was in the environment on the screen. In that sense, I was not simply a passive viewer, but a silent participant. (This VR experience is, in fact, passive.)
The Virtual Human Interaction Lab at Stanford has done and is doing a lot of research about how we experience virtual reality--how it is similar to and different from our experience of "reality." They've also done research on how VR can be used to change our behavior for the better (including exercise more, eat less, and plan for old age). You can peruse their publications here and I highly recommend this overview article by Jesse Fox, Dylan Area, and Jeremy Bailenson. (Note: Their definition of VR is somewhat different than the one I'm using here.)