Researchers in Switzerland have cast new light on so-called out-of-body experiences (OBEs) by triggering the experience through electrical stimulation of the brain. The find suggests that OBEs call on a part of the brain implicated in other illusory bodily perceptions.
Inadvertently, neurologist Olaf Blanke of the University Hospitals of Geneva and Lausanne and colleagues induced an OBE in a 43-year-old woman suffering from epilepsy. In an attempt to locate the source of the seizures, the researchers placed electrodes on the surface of the brain that delivered mild shocks to various points. When they stimulated the right angular gyrus, located roughly behind the right ear, the patient repeatedly reported having the sensation of floating above the bed and seeing herself lying below. She also experienced various distorted sensations about the positions of her arms and legs, the authors report in the 19 September issue of Nature.
The angular gyrus has been implicated in illusions such as the experience of phantom limbs after amputation. The scientists say it may be part of a larger circuit, including the adjacent vestibular system (which keeps tabs on the position of the head in space), that mediates "own-body perception." They speculate that the experience of being dissociated from one's body could be the result of a failure to integrate information from these two areas. Brain researcher Antonio Damasio of the University of Iowa, Iowa City, says he once encountered a patient with damage to this brain area who also experienced going out of her body during seizures.
The value of this research, Damasio says, is that it has nailed down the "part of the brain involved in constructing the highest level of body representation we have." The Blanke team's finding has been "a long time coming," adds psychologist and consciousness researcher Susan Blackmore of Bristol, U.K. Blackmore says that a half-century ago pioneering brain surgeon Wilder Penfield "stimulated a woman's brain with a crude electrode and she said 'Oh my god I'm leaving my body.' That stood as the single example for more than 50 years."