How you wake up might explain near death experiences

According to a new study, people who have had near death experiences often have different arousal systems controlling the sleep-wake states than people who have never had such an experience.

The study defined a near death experience as a time when a person experiences a variety of feelings, including a sense of being outside of one's physical body, unusual alertness, seeing an intense light, and a feeling of peace during a life-threatening episode of danger such as a car accident or heart attack.

The study compared 55 people with near death experiences to 55 people of the same age and gender who had not had near death experiences.

The researchers found that people with near death experiences were more likely to have a sleep-wake system where the boundaries between sleep and wakefulness are not as clearly regulated, and the REM (rapid eye movement) state of sleep can intrude into normal wakeful consciousness.

Such examples of this include waking up and feeling that one cannot move, having sudden muscle weakness in one's legs, and hearing sounds just before falling asleep or just after waking up that other people can't hear.

Of those in the study who had had a near death experience, 60 percent reported having times of REM intrusion, compared to 24 percent of people who had not had near death experiences.

Neurologist and study author Kevin R. Nelson, MD, FAAN, of the University of Kentucky in Lexington, says the findings suggest that REM state intrusion contributes to near death experiences and people who have near death experiences may have an arousal system that predisposes them to REM intrusion.

Nelson says several other factors support this theory as many features of near death experiences are also associated with the REM state such as the feeling of being outside of one's body which has been associated with the REM state and the conditions of sleep paralysis, narcolepsy and seizures.

The feeling of being surrounded by light could he says be based on the visual activity that occurs during the REM state, as the muscles can lose their tone, or tension at that time.

REM state intrusion is also associated with other disorders, such as narcolepsy and Parkinson disease.

The study is published in the April 11, 2006, issue of Neurology, the scientific journal of the American Academy of Neurology.