People who have had near death experiences often have different arousal systems controlling the sleep-wake states than people who have not had a near death experience, according to a new study published in the April 11, 2006, issue of Neurology, the scientific journal of the American Academy of Neurology.
For the study, a near death experience was defined as a time during a life-threatening episode of danger such as a car accident or heart attack when a person experienced 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.
The study, which is published in Neurology's "Views & Reviews" section, compared 55 people with near death experiences to 55 people of the same age and gender who had not had near death experiences.
The study found that people with near death experiences are 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. Examples of this REM intrusion include waking up and feeling that you cannot move, having sudden muscle weakness in your legs, and hearing sounds just before falling asleep or just after waking up that other people can't hear.
Of the people with near death experiences, 60 percent reported having times of this REM intrusion, compared to 24 percent of people who had not had near death experiences.