The New York Times, August 24th, 2007
Using virtual reality goggles, a camera and a stick, scientists have
induced out-of-body experiences — the sensation of drifting outside of
one’s own body — – in healthy people, according to experiments being
published in the journal Science.
When people gaze at an illusory image of themselves through the
goggles and are prodded in just the right way with the stick, they feel
as if they have left their bodies.
The research reveals that
“the sense of having a body, of being in a bodily self,” is actually
constructed from multiple sensory streams, said Matthew Botvinick, an
assistant professor of neuroscience at Princeton University, an expert on body and mind who was not involved in the experiments.
Usually
these sensory streams, which include vision, touch, balance and the
sense of where one’s body is positioned in space, work together
seamlessly, Prof. Botvinick said. But when the information coming from
the sensory sources does not match up, when they are thrown out of
synchrony, the sense of being embodied as a whole comes apart.
The
brain, which abhors ambiguity, then forces a decision that can, as the
new experiments show, involve the sense of being in a different body.
The
research provides a physical explanation for phenomena usually ascribed
to other-worldly influences, said Peter Brugger, a neurologist at
University Hospital in Zurich, Switzerland. After severe and sudden
injuries, people often report the sensation of floating over their
body, looking down, hearing what is said, and then, just as suddenly,
find themselves back inside their body. Out-of-body experiences have
also been reported to occur during sleep paralysis, the exertion of
extreme sports and intense meditation practices.
