Wednesday, October 21, 2009

Out of the Body Experience

An article by Anil Ananthaswamy at New Scientist probes the phenomenon of out of the body experiences. These events appear to be generated by a particular part of the brain called the temporoparietal junction (TPJ), but exactly what is going on in these experiences, which researchers don't doubt are genuine, remains a mystery.

Ananthaswamy seems to assume a dualistic view of the body and the self with the self somehow tied to the body unless released by certain triggers. Here's an account of one such episode that he cites as an introduction to his article:

The young man woke feeling dizzy. He got up and turned around, only to see himself still lying in bed. He shouted at his sleeping body, shook it, and jumped on it. The next thing he knew he was lying down again, but now seeing himself standing by the bed and shaking his sleeping body. Stricken with fear, he jumped out of the window. His room was on the third floor. He was found later, badly injured.

What this 21-year-old had just experienced was an out-of-body experience, one of the most peculiar states of consciousness. It was probably triggered by his epilepsy. "He didn't want to commit suicide," says Peter Brugger, the young man's neuropsychologist at University Hospital Zurich in Switzerland. "He jumped to find a match between body and self. He must have been having a seizure."

In the 15 years since that dramatic incident, Brugger and others have come a long way towards understanding out-of-body experiences. They have narrowed down the cause to malfunctions in a specific brain area and are now working out how these lead to the almost supernatural experience of leaving your own body and observing it from afar. They are also using out-of-body experiences to tackle a long-standing problem: how we create and maintain a sense of self.

Dramatised to great effect by such authors as Dostoevsky, Wilde, de Maupassant and Poe - some of whom wrote from first-hand knowledge - out-of-body experiences are usually associated with epilepsy, migraines, strokes, brain tumors, drug use and even near-death experiences. It is clear, though, that people with no obvious neurological disorders can have an out-of-body experience. By some estimates, about 5 per cent of healthy people have one at some point in their lives.

So what exactly is an out-of-body experience? A definition has recently emerged that involves a set of increasingly bizarre perceptions. The least severe of these is a doppelg�nger experience: you sense the presence of or see a person you know to be yourself, though you remain rooted in your own body. This often progresses to stage 2, where your sense of self moves back and forth between your real body and your doppelg�nger. This was what Brugger's young patient experienced. Finally, your self leaves your body altogether and observes it from outside, often an elevated position such as the ceiling. "This split is the most striking feature of an out-of-body experience," says Olaf Blanke, a neurologist at the Swiss Federal Institute of Technology in Lausanne.

All this raises several questions: What exactly is it that's "outside" the body? Is it really outside the body or is the outsideness an illusion? If it is illusory how does it perceive things from an "outside" perspective? Is there something about us that's immaterial and yet can still perceive and move? How does it do this if it has no sense organs and no locomotive system? Can both the "outside" self and the body have simultaneous cognitive experience, i.e. can the mind be split between the two?

There's a debate among philosophers whether minds actually exist as a substance separate from material bodies and brains. Materialists usually hold that minds have no actual existence. For them mind is just a word we use to describe the function of the brain much like we use the word digestion to describe the function of the stomach. Dualists, on the other hand, believe that minds are an altogether different kind of "substance," an immaterial substance, from material bodies. No doubt materialists will try to explain out of body experiences in terms of purely physical mechanisms giving rise to illusory experience, but I don't see how the weight of the evidence doesn't at least offer prima facie support to mind/body dualism.

Read the rest of the article and see what you think.

RLC