What causes out-of-body experiences?

Few sensations are weirder than the bizarre feeling that you are floating outside your own body. "Out of body" experiences are a mysterious phenomenon that's often mixed up in the occult, but scientists are still trying to puzzle out how it works.

About one in ten people will have an out-of-body experience at some point in their lives, and many will multiple such experiences. The term itself was first introduced back in 1943 to get away from more loaded terms like "astral projection" or "spirit walking", but in the seven decades since science still can't offer too many concrete explanations for what causes this phenomenon.

There seems to be some association between out-of-body experiences and mind-altering events such as trauma, sensory deprivation, drug use, or even dehydration. But even these links don't hold true 100% of the time - some people seem to experience these out-of-body sensations for little or no reason. That suggests some people are predisposed to these experiences, but figuring out just what underpins this has proven tricky.

To that end, researchers at the University of Birmingham tested 63 normal, healthy individuals, 17 of whom reported out-of-body experiences in their past. One test involved imitating the position of a mannequin and then working out on which hand the mannequin was wearing a piece of jewelry. Those who had had out-of-body experience struggled with this exercise, indicating difficulty in melding sensory information and knowledge of the body's position together.

Those who had had out-of-body experiences repeatedly demonstrated behaviors linked with neuroelectrical anomalies in the temporal lobes, as well as general distortions in the brain's ability to process information coming from the body as a whole. All of these taken together point to minor but crucial deficiencies in the brain, and these might well explain why some people have much weaker mental links to their own bodies - which seems like a natural prerequisite for out-of-body experiences.

Via Cortex. For more on this story, check out Scientific American (subscription only).