Near-Death Experiences Linked to Sleep Cycles

Tuesday, April 11, 2006

As many as 10 percent of survivors of heart attacks report having a near-death experience -- such as feelings of transcendence, being surrounded by light or floating outside their bodies.

New research announced yesterday suggests a biological explanation for such phenomena: People with near-death experiences are more likely to have different sleep-wake mechanisms in their brains.

In a study comparing 55 people with near-death experiences with 55 people who had no such experiences, neurologist Kevin Nelson of the University of Kentucky found that people who reported such experiences were also more likely to report a phenomenon known as "REM intrusion," where things normally experienced during sleep carry over into wakefulness. REM is an acronym for rapid eye movement, one of the phases of sleep.

Such people wake up but still feel paralyzed or hear sounds that others do not -- as the vestiges of sleep fall away, those experiences disappear. It is not considered a disorder, but merely a variant of the brain's sleep-wake cycle.

Nelson, who published his findings in the journal Neurology, said the extreme fear or feeling of danger brought on by imminent death might trigger the brain mechanism that governs the transition between sleep and wakefulness, leading people to experience various dreamlike phenomena.

The neurologist added that religious and cultural beliefs clearly influenced near-death experiences, and stressed that his findings only spoke to how such a brain mechanism might work, and not why it would work that way.

-- Shankar Vedantam

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