Tuesday, June 19, 2012

Out-of-body experience

An out-of-body experience (OBE or sometimes OOBE) is an experience that typically involves a sensation of floating outside of one's body and, in some cases, perceiving one's physical body from a place outside one's body (autoscopy).

The term out-of-body experience was introduced in 1943 by George N. M. Tyrrell in his book Apparitions, and adopted by, for example, Celia Green and Robert Monroe as a bias-free alternative to belief-centric labels such as "astral projection", "soul travel", or "spirit walking". Though the term usefully distances researchers from scientifically problematic concepts such as the soul, scientists still know little about the phenomenon. Some researchers believe they have managed to recreate OBE in a laboratory setup by stimulating a part in the human brain. One in ten people has an out-of-body experience once, or more commonly, several times[6] in his or her life. OBEs are often part of the near-death experience. Those who have experienced OBEs sometimes claim to have observed details which were unknown to them beforehand.

In some cases the phenomenon appears to occur spontaneously; in others it is associated with a physical or mental trauma, dehydration, sensory deprivation, sensory overload, use of psychedelic drugs, dissociative drugs, or a dream-like state. Many techniques aiming to induce the experience deliberately have been developed, for example visualization while in a relaxed, meditative state. Recent (2007) studies have shown that experiences somewhat similar to OBEs can be induced by electrical brain stimulation (particularly the temporoparietal junction). Some of those who experience OBEs claimed to have willed themselves out of their bodies, while others report having found themselves being pulled from their bodies (usually preceded by a feeling of paralysis). In other accounts, the feeling of being outside the body was suddenly realized after the fact, and the experiencers saw their own bodies almost by accident.

Some neurologists have suspected that the event is triggered by a mismatch between visual and tactile signals. They used a virtual reality setup to recreate an OBE. The subject looked through goggles and saw his own body as it would appear to an outside observer standing behind him. The experimenter then touched the subject at the same time as a rod appeared to touch the virtual image. The experiment created an illusion of being behind and outside one's body. However, both critics and the experimenter himself note that the study fell short of replicating "full-blown" OBEs.