Using virtual-reality goggles, a camera and a stick, scientists have induced out-of-body experiences — the sensation of drifting outside of one’s own body — in ordinary, healthy people, according to studies being published today in the journal Science. When people gazed at an illusory image of themselves through the goggles and were prodded in just the right way with the stick, they felt as if they had left their bodies. The research reveals that “the sense of having a body, of being in a bodily self,” is actually constructed from multiple sensory streams, said one expert on body and mind, Dr. Matthew M. Botvinick, an assistant professor of neuroscience at Princeton University. Usually these sensory streams, which include vision, touch, balance and the sense of where one’s body is positioned in space, work together seamlessly, Dr. Botvinick said. But when the information coming from the sensory sources does not match up, the sense of being embodied as a whole comes apart. The brain, which abhors ambiguity, then forces a decision that can, as the new experiments show, involve the sense of being in a different body.

Humans normally experience the conscious self as localized within their bodily borders. This spatial unity may break down in certain neurological conditions such as out-of-body experiences, leading to a striking disturbance of bodily self-consciousness. On the basis of these clinical data, we designed an experiment that uses conflicting visual-somatosensory input in virtual reality to disrupt the spatial unity between the self and the body. We found that during multisensory conflict, participants felt as if a virtual body seen in front of them was their own body and mislocalized themselves toward the virtual body, to a position outside their bodily borders. Our results indicate that spatial unity and bodily self-consciousness can be studied experimentally and are based on multisensory and cognitive processing of bodily information.