Out-of-Body Experiences Tested in Lab

Ever had an out-of-body experience, where you were wide
awake and "saw" your body as if you were a bystander?

Scientists may have figured out how out-of-body experiences happen. Turns
out, it's all about the eyes.

Two new studies -- both published in tomorrow's edition of the journal
Science -- put a state-of-the-art spin on out-of-body research.

In one experiment, 14 healthy, young adults wore virtual-reality goggles as
they stood in the researchers' lab. A few feet behind them, a video camera
filmed their backs and projected that image, in real time, into a hologram a
few feet in front of the participants.

The researchers stroked the participants' real and virtual back at the same
time. Afterward, they only stroked the participants' virtual back -- but even
so, participants said they had the sensation that their real backs were being
touched.

Participants didn't lose all sense of themselves. They didn't report feeling
like they had left their bodies.

But they did describe the sensation as weird or strange, according to Olaf
Blanke, MD, PhD, and colleagues. Blanke directs the Laboratory of Cognitive
Neuroscience at the Ecole Polytechnique Federale de Lausanne in Lausanne,
Switzerland.

Blanke's team did similar tests on 14 other participants to confirm the
findings.

The other study also used virtual reality and video cameras to simulate
out-of-body experiences. But neuroscientist H. Henrik Ehrsson, MD, PhD, pushed
the envelope a little farther.

Ehrsson works at University College London and the Karolinksa Institute in
Stockholm, Sweden. In a series of experiments, Ehrsson found that participants
"felt" touch applied to virtual-reality versions of their bodies.

What's more, when Ehrsson pretended to strike participants' virtual bodies
-- not their true selves -- with a hammer, participants were scared for their
actual flesh and blood, though they had been promised that they weren't in any
danger whatsoever.

"This experiment suggests that the first-person visual perspective is
critically important for the in-body experience," Ehrsson says in a news
release. "In other words, we feel that our self is located where the eyes
are."

By Miranda Hitti
Reviewed by Louise Chang
B)2005-2006 WebMD, Inc. All rights reserved