treating phobias in virtual reality
TREATING PHOBIAS IN VIRTUAL REALITY
The ability to quickly and easily make changes to a virtual environment, and particularly the ability to reproduce dangerous situations while totally avoiding the possibility of any real harm, makes virtual reality a very useful tool for treating phobias or to come to terms with traumatic events. A common method for helping sufferers with arachnophobia and other irrational fears is systematic desensitization, whereby the patient undergoes increasingly intimate encounters with their object of dread. In the case of spiders, this could initially consist of entering a room in which there is a spider in a glass tank that is covered by a cloth. Then, on a subsequent session, being in a room in which the cloth is removed and the spider in the tank is in clear sight. Step by step, the patient becomes gradually desensitized to the point where they are confident enough to allow a tarantula to crawl up their arm.
The problem with this technique is that it entails working with live creatures that need looking after, and that costs time and money. And, as you can imagine, treating something like a fear of flying is costlier still. But, of course, by using virtual reality the costs can be dramatically lowered and we are also able to exercise a degree of control that would not be possible using live actors or mechanical devices.
Working with Dr JoAnn Difede, assistant professor of psychiatry at Newyork Presbyterian hospital, Dr Hunter Hoffman (who had previously found that the escapism of virtual reality is powerful enough to enable burns victims to reduce the perception of pain while their burns are being redressed by fifty to ninety percent) developed a virtual recreation of the attack on the Twin Towers. Little by little, those traumatized by the events of 9/11 encounter increasingly intense recreations, beginning with looking up at the World Trade Center, with no airplanes flying by let alone crashing, and then gradually more and more elements are added in, such as explosions and the sounds of people panicking. Using this technique, patients who had not responded to any other physiological treatment showed dramatic improvement.
And, like I said, the cost of doing this virtually is negligible compared to real life. And as Moore's law marches on the costs keep going down. When Dr Hoffman started working with burns victims in 1996, a decent VR machine cost about $45,000. In 2016, when the likes of the Oculus Rift are expected to launch, a budget of under $1000 would almost certainly get you a VR setup as good, if not better, than that 90s example.
IMMERSION VERSUS PRESENCE
To those who have never experience a VR setup, it may be hard to believe that fictional recreations can help with real trauma. Everybody knows that something virtual is not real, so how can being in a pretend airplane cure somebody's fear of flying?
But to think that way would be to ignore the power of 'presence'. Presence is not the same thing as immersion. Videogames have long achieved a sense of immersion, the capability to draw players into the game and invest in their avatar and the challenges they are setting out to beat. You do not need photorealism to achieve immersion but you do need consistency of rules. So, for example, if the game prevents you from jumping over what looks like a totally clearable obstacle for some arbitrary reason, your attention is directed to fact that you are just playing a game. In some ways, realism can work against immersion, because it is much harder to achieve consistency of rules that match realism compared to a simple fantasy game that stays true to its own internal logic. You only have to watch the documentary movie 'King Of Kong' (about the two best Donkey Kong champions competing to achieve the highest possible score) to see how absorbed one can become with simple graphics and consistent rules.
But, no matter how engrossing a videogame can be, immersion is not the same thing as presence. The way videogames are traditionally played, the avatar is something you control and the environment it is in is observed from afar, viewed on a monitor. When videogame technology achieves presence, though, you perceive yourself as literally inhabiting a VR environment.
As with immersion, photorealism is not the most important thing for achieving presence. What is important is that the display offers a wide enough field of view to prevent one from seeing the edges, and that the tracking and rendering technology is capable of updating the point of view fast enough to avoid noticeable latency. According to John Carmack, "twenty milliseconds or less will provide the minimum level of latency deemed acceptable" and if it can be reduced to 18 milliseconds or less, the experience will be perceived as immediate, meaning you can move your head and redirect your gaze in a way that feels entirely natural.
DARE YOU CROSS 'THE PIT'?
A common way of testing whether a VR setup has achieved presence is to have subjects undergo 'The Pit'. As its name suggests, this is a VR experience in which you find yourself standing before a pit. Not a shallow pit, mind you, but a very long drop. There is also a plank spanning the pit (plus a real plank in the actual room in which the experiment takes place) and people are challenged to walk across the real plank while they perceive themselves as walking across the sheer drop.
Now, obviously, there is no pit in real life and the subjects know this. Nevertheless, according to Blascovich and Bailenson, one in three adults cannot summon up the courage to walk the plank, and those that do try struggle to maintain balance just as if they were really trying to cross a long drop. This happens because the brain's perceptual systems (ones operating below the level of conscious awareness) are satisfied that the experience is real. And no matter how much you tell yourself the experience is only virtual, your brain insists you are doing something risky like standing close to the edge of a precipice.
Tracking and rendering technology has long been used to convince the mind to accept something artificial as natural. Undoubtedly the most commonly used example would be the telephone. When you say something during a phone conversation, the inbuilt microphone 'tracks' your voice by digitizing it. And what the listener hears is not really your voice but a reproduction that approximates the sound of your voice, 'rendered' by his or her phone's inbuilt speaker. Because the sounds being heard are so close to that of a human voice, your mind believes that is what you are listening to, and we have long-since adopted the attitude that a phone conversation is a direct two-way conversation between people who are physically distant, not a conversation mediated by artificial sounds that repeat what is being said.
So, if tracking and rendering works well enough to achieve presence, the more primitive parts of the brain will be convinced the experience is real. For that reason, VR has proven extremely useful as a tool of therapy for people with phobias and other traumas that can be treated by repeat exposure to whatever threatens them.
