For centuries, the out-of-body experience, in which consciousness seems to float away from the body, has been widely regarded as a spiritual or mystical phenomenon. Some parapsychologists still believe that such experiences are just what they seem to be: a separation of consciousness from the body.

Recent research, however, has produced evidence that out-of-body experiences and a related phenomenon, the near-death experience, are produced by abnormal brain activity.

At every moment, the brain effortlessly integrates information from the body into a strong, seamless sense of self. The proprioceptive system, for example, sends signals to the brain that allow you to know, without looking, where your hands, legs and feet are. The vestibular system in the inner ear relays information about your orientation to gravity. (Are you vertical, horizontal, or somewhere in-between?)

The brain’s synthesis of this and other information creates a sense of being inside your body. The out-of-body experience, in contrast, produces a sensation of consciousness floating upward, providing a view of the body from an elevated perspective. It results from a breakdown of the brain’s ability to synthesize signals from the body.

Although out-of-body experiences are reported most often in people with epilepsy and migraine, they also occur in about 10 percent of the healthy population and have been reported in cultures around the world, suggesting that they are rooted in brain physiology. They are difficult to study, however, because they seldom occur more than once in a lifetime.

Close study of out-of-body experiences has led Olaf Blanke, a neurologist at University Hospital in Geneva and a researcher at the Brain-Mind Institute in Lausanne, to believe that this breakdown occurs in the temporoparietal junction (TPJ). This region processes signals that contribute to the sense of balance. Disruption of these signals can induce a sense of floating or falling.