Imaginary figment?: Experimental induction of out-of-body experiences. Through the goggles, the volunteer is viewing the back of his body, as seen from behind by the camera. He is also watching a plastic rod moving toward a location just below the camera while his real chest is simultaneously touched in the corresponding spot.

Credit: Henrik Ehrsson

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CHICAGO: Throughout history, people have reported having out-of-body experiences, but now scientists have recreated the sensation for the first time without drugs.

As many as one in ten people say they have experienced the sensation of being awake and seeing their own body from another location, according to the study published in the U.S. journal Science today.

"Out-of-body experiences have fascinated mankind for millennia. Their existence has raised fundamental questions about the relationship between human consciousness and the body," said Henrik Ehrsson, a neuroscientist formerly of University College London, and now at the Karolinska Institute in Sweden.

Distorted perception

Now his team have manipulated a group of perfectly healthy volunteers into thinking they had moved outside their bodies by distorting their perception of reality.

Using virtual reality goggles to mix up the sensory signals reaching the brain, they induced the volunteers into projecting their awareness into a virtual body.

Participants confirmed they had experienced sitting behind their physical body and looking at it. The illusion was so strong that the volunteers reacted with a palpable sense of fear when their virtual selves were threatened with physical force.

The findings suggest there may be a scientific explanation for these types of out-of-body experiences, which had often been thought of as delusional or paranormal, and the scientists believe their research could have important applications.

"The invention of this illusion is important because it reveals the basic mechanism that produces the feeling of being inside the physical body," said Ehrsson. "This represents a significant advance because the experience of one's own body as the centre of awareness is a fundamental aspect of self-consciousness."

"Form of teleportation"

And inducing people to have out-of-body experiences could have wide-ranging uses, he believes. "This is essentially a means of projecting yourself, a form of teleportation. If we can project people into a virtual character, so they feel and respond as if they were really in a virtual version of themselves, just imagine the implications.

"The experience of video games could reach a whole new level, but it could go much beyond that. For example, a surgeon could perform remote surgery, by controlling their virtual self from a different location."

The study reveals that visual perspective and coordination between vision and touch are important for the sensation of being within the body, neuroscientist Peter Brugger of University Hospital Zurich in Switzerland told Science in a related news article. However, though the illusions were the best possible in a lab, Brugger said the experiments didn't precisely replicate the "enormously compelling sensation of separation from the body" reported in some real out-of-body experiences.

Scientists still don't know exactly what causes such experiences, which have often been associated with traumatic experiences such as car accidents and linked to compromised brain function in epileptics, drug addicts and stroke victims.

"Brain dysfunctions that interfere with interpreting sensory signals may be responsible for clinical cases of out-of-body experiences," said Ehrsson. "Though, whether all out-of-body experiences arise from the same causes is still an open question."