The experience of seeing yourself outside your own body, often associated with neurological conditions or traumatic experiences such as car accidents, has been recreated in a laboratory setting with healthy participants in two separate experiments.

The two studies, published Thursday in the journal Science, introduced methods of inducing elements of out-of-body experiences using virtual reality technology to trick the participants with a combination of visual and physical stimuli.

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. (Image courtesy of Henrik Ehrsson/Science)

Dr. Henrik Ehrsson of the Karolinka Institute in Stockholm was the lead researcher of one of the studies while at University College London. He suggests the findings provide scientific basis to an experience often thought to be a figment of the imagination.

"Although out-of-body experiences have been reported in a number of clinical conditions, the neuro-scientific basis of this phenomenon remains unclear," he said in a statement.

"The invention of this illusion is important because it reveals the basic mechanism that produces the feeling of being inside the physical body."

In one of the studies, Ehrsson had participants sit on a chair and wear a pair of head-mounted displays connected to two cameras placed side by side, two metres behind their backs. When wearing the goggles, participants would see themselves from the perspective of someone sitting behind them.

The experimenter then used two plastic rods to touch both the person's actual chest and the chest of the "illusory body." After questioning, participants strongly identified with their virtual body and felt they were behind themselves. This was confirmed by a second test, in which the experimenter measured the participant response after pretending to strike a hammer down on the "virtual body."

Bigna Lenggenhager and Olaf Blanke, Swiss Federal Institute of Technology researchers, conducted a separate study using similar methods: participants stood in front of a camera while wearing visual display goggles, and were both physically and visually stimulated by having a highlighter pen rubbed against their backs and their virtual backs.

When the researchers moved the participants, turned off the video display and then asked them to return to their former spots, they also overshot their former positions, standing closer to where their virtual bodies were.

Ehrsson said the results have implications in everything from neuroscience to theology. The results of the research, he said, could not only be used to better understand the brain processes at work during an out-of-body experience, it could also result in better applications of a more real virtual reality.

"This is essentially a means of projecting yourself, a form of teleportation," he said.

"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 playing 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."