For most of us out-of-body experiences are strictly the realm of science fiction, yet many people still claim to have experienced them. The cause for these feelings of detachment is not known, but that's exactly what a group of European scientists scientists are trying to figure out.
The term "out-of-body experience" is described by the researchers as a feeling of corporeal detachment and looking at your body from a distance. Two sets of researchers claim they've devised experiments that come close to replicating an out-of-body experience. The findings from the study are reported in this month's issue of Science Magazine (subscription required).
Researchers believe this feeling is a result of our normal sensory systems of touch, sight and vision becoming disconnected under stress. Dr. Kevin Nelson, a researcher into near-death phenomena, who wasn’t involved in the research says, “[the new research] shows that the integration of various sensory modalities is important for retaining our sense of where our body is, of where our self is in that body,"
Henrik Ehrsson of the Karolinska Institure in Stockholm, Sweden set up his study using volunteers equipped with 3-D goggles used to view real-time 3-D footage of themselves seen from six feet behind where they were actually sitting. Ehrsson would use a plastic rod to touch the real chest and the back of the participant, without the participant seeing him touch their chest.
This technique allowed participants to feel the touch on their chest, but they could only see Ehrsson's hand moving behind their back, which produced the feeling that they were sitting at a location behind their body.
Ehresson also swung a hammer at the point where participant believed their body to be. This created the illusion that the distant version of the participant’s body was going to be hit. Sensors placed on the skin of participants showed increase in sweat production indicating that they felt the threat of being hit was real, which showed that they believed the virtual body to be their own.
A second team led by Bigna Lenggenhager and Olaf Blanke, both from the Swiss Federal Institute of Technology in Lausanne, set up a similar experiment where participants donned video-display goggle while standing in front of a camera. In one experiment participants saw a view of their back, which was computer enhanced to become 3-D. Participants then were stroked on their back with a highlighter pen at the same time they saw their virtual back being stroked. Participants reported that the sensation felt like it was coming from the virtual back, not their real back, making them feel the virtual body was their own.
After the stroking the participant was blind folded, moved back from where they were originally standing and told to return to their previous position. The participants typically were not able to return to the correct spot where they were originally standing, but advanced to the spot where their virtual body was located. This again points to participants believing that the virtual body was actually their own.