First aired on
The Current (03/01/11)
Near-death experiences — people who have had them frequently describe them as profoundly spiritual, as life-altering events offering rare insight into one of the universe's biggest mysteries.
Kevin Nelson, however, has another, more scientific, way of thinking about them. A physician and professor of neurology at the University of Kentucky Medical Centre, Nelson is the author of a new book called The Spiritual Doorway in the Brain: A Neurologist's Search for the God Experience.
Nelson has been studying near-death experiences for three decades. As he explains, there really isn't much of a mystery surrounding the phenomenon. Most near-death experiences are triggered by some kind of physical crisis, such as heart irregularities or fainting, that diminish the flow of blood to the brain.
"We actually know a great deal about the out-of-body experience," Nelson told host Anna Maria Tremonti in a recent interview on The Current. "If we take an electrical current and apply it to the surface of the brain in one discrete area, we can take someone out of their body with the flip of a switch."
According to Nelson, out-of-body and near-death experiences result from a type of confusion in the brain between its three states of consciousness — alertness, REM sleep and non-REM sleep.
"When we're in crisis, we expect to be awake and alert to face that crisis," Nelson said. "That is such an obvious question that we take it for granted, but the brain can't take it for granted."
In his studies of the phenomenon, Nelson found that the link between waking and REM consciousness is different in people who have had a near-death experience. Rather than passing directly from REM to waking, their experience is more likely to blend those states. This blending can be expressed as sleep paralysis, or visual and auditory hallucinations. And it can be easily triggered by a physical crisis restricting blood flow to the brain.
Although he has dedicated a significant part of his career to uncovering the biological basis of a deeply metaphysical experience, Nelson is careful not to dismiss its importance for those who experience it. In fact, he closes the book by referring to the brain as a spiritual organ that strengthens our quest for meaning.
"It's important to understand how the brain works so that we can better understand our place in the universe," he said. "There will still be a mystery of spirituality that will always be with us."