An out-of-body experience (or OBE) is an experience in which a person seems to see the world from a location outside of the physical body. In other words, when you have an OBE you feel as though you have left the body and are able to see, feel, and move around without it. Note that this definition treats the OBE as an experience only. So if you feel as though you are out of your body then you are-by definition-having an OBE, whether or not anything has actually left the body. As Palmer (1978) pointed out: The OBE is neither potentially nor actually a psychic phenomenon. It is an experience or mental state, like a dream or any other altered state of consciousness. It may be associated with psi, but it is not a psychic phenomenon itself.' This broad definition allows researchers to study the experience without committing themselves to any particular theory of the OBE.
Surveys show that about 15 to 20 per cent of the population have had an OBE at some time during their life (Blackmore 1982, 1996). Most of these people only have one, or a very few OBEs, although a few have many. Some people find the experience frightening but others value the pleasant sensations and visions, and some even learn to induce the experience at will.
Spontaneous OBEs most often occur during resting, just before sleep or when meditating. However, OBEs can occur at almost any time and occasionally the person carries on with what they were doing (such as walking, driving or even speaking) apparently without interruption. Common factors that provoke OBEs include relaxation, loss or disruption of body image, and reduced sensory input. Most spontaneous OBEs are very brief, lasting only a few seconds. Some begin with the experience of travelling down a dark tunnel, often with a bright white or golden light at the end. Others begin with rushing or whirring noises, odd vibrations or simply a brief period of blackout. Returning is usually gradual but occasionally