People resuscitated from "clinical death"--when a machine scanning for brain activity goes blank--often claim they experience visions. Some patients have watched instant replays of their lives; others have watched the medical teams call them back to life (one man informed nurses where they'd misplaced his dentures during his CPR). Most report a feeling of peace--and many point to this as proof that there is an after-life.
In the past, scientists have attempted to explain near-death experiences (NDEs) as the product of brain activity or "false memories" concocted after-the-fact.
But the Dutch study interviewed patients soon after their near-deaths when their memories were fresh, reducing the likelihood the experiences were "false memories."
They also checked to see if NDEs might match up with particular medications the subjects had been taking or to the presence of natural chemicals like endorphins or serotonin in the brain, or the absence of oxygen (the most common cause of brain death). They found no connection.
Psychological factors, like fear, were also eliminated. Perhaps most importantly, the researchers found that fewer than 12 percent of the revived had NDEs at all. If marching toward a light or an out-of-body experience is simply part of bodily death, the researchers say, all of the subjects should have reported one.
After studying these various factors, scientists could not link NDEs to any of these biological or psychological causes.
The researchers in the Netherlands study also met with their subjects two and eight years after they had been revived and found that more of them had a belief in the afterlife and a decreased fear of death.
Even with improved data, scientists are far from proving the existence of life after death. "It may mean we need a much more sophisticated understanding of the brain than we have currently, or it may mean that the workings of the brain do not hold the entire answer," says Dr. Bruce Greyson of the University of Virginia, who has studied NDEs.
In other words, it leaves scientists with a puzzle. "How could a clear consciousness outside one's body be experienced at the moment that the brain no longer functions?" asks Pim van Lommel, the current study's lead researcher.
The study also found: