Near-death experience

Near-death experience, also known as NDE, is the common name for feelings, impressions and out-of-body experiences reported by people who have been resuscitated after a cardiac arrest.

Such reports date back to the time of Plato who wrote about the Myth of Er. Researchers Raymond Moody, Elisabeth Kübler-Ross, Bruce Greyson, Kenneth Ring, and Michael Sabom have all researched and wrote about this subject. Greyson, Ring and Saborn helped start the field of Near-Death studies In the strictest sense an NDE occurs when someone is near death or has died. Both adults and children report similar NDE experiences. Similar experiences have been reported by others, who had not died, but NDE researchers do not consider them true NDEs. These experiences may occur when someone is participating in meditation, under emotional duress or at the bedside of a dying loved one. NDE researchers are studying this phenomena as part of their NDE research.

When do NDEs occur?
NDEs occur once a person's heart function stops causing the blood supply to cut off to the brain. This usually takes between 11 to 20 seconds once the heart function ends. An electroencephalogram (EEG) reading taken during this time will show a flat brain waves. Retired Dutch cardiologist Pim van Lommel says when the body is in this state it is like a computer that is unplugged from its power source with its circuits detached. “It couldn't hallucinate. It couldn't do anything at all,” says Lommel in an interview with Time magazine. Many NDE researchers believe this is the time period when NDEs are likely to occur. “"Many near-death experiencers describe heightened perceptions and clear thought processes, and form memories, at a time when the brain is incapable of coordinated activity," says Greyson, director of the University of Virginia's Division of Perceptual Studies. "Our current neurophysiological models can explain NDEs only if one ignores much of the empirical data,” he said during his interview with Time magazine.

Commonly reported experiences
In general the NDE experience goes through the following steps:

Another description of the NDE event is given in the Near-Death Experiences: Is this what happens when we die. In this report people who experienced an NDE detailed most of the experiences reported by Ring.
 * Hearing the News
 * Feeling of peace and quiet
 * The noise
 * The dark tunnel
 * Out-of-body experience
 * Meetings others
 * The Being of Light
 * The Review
 * The border or limitk

Ring estimates 23 million Americans have had NDEs, and that no matter the cause of death or religious persuasion; people have neared biological death, or died, have reported NDEs.

Negative experiences
Not everyone reports NDEs as being pleasant. Greyson states some people report hellish experiences. A woodcutter, who attempted suicide by hanging, described hearing but not seeing demons. Some how he was able to alert his wife during his NDE experience who ran to her husband and cut him down. This all happened and was reported by him during his NDE experience. He was later revived by emergency personnel and lived to tell about his NDE. Some researchers believe his cry for help was heard through telepathy. Other experiences commonly reported moving towards the tunnel of light and other commonly reported features except the person felt out of control during the experience. Another experience reported includes being an absolute void. Some have also reported they felt like the world never existed. Finally, a rare form of NDE is when the person reports a negative life review and negatively judged. Approximately 1 to 15 percent of people report negative NDEs. A negative NDE is not based on the cause of death or religious background. Further research is planned.

NDE effects
Research has shown the NDE experience has long-term effects. People who have died and returned to report the NDE often change lifestyles. Women may become more outspoken while men may become emotionally in tune. Other effects may include learning to love universally, looking at time as flowing or “to flow with events.” Some people have reported developing psychic abilities such as extrasensory perception (ESP) after their NDE experience. Children may develop a lessening of the bonds between parent and child; increased sensitivity to others; increased service to others, increased interest in spirituality; communication with spirits (often called angels or guides by the child); sensitivity to bright lights, loud noises and medications; a strong desire to volunteer for charitable causes. Children who reported an NDE may also develop altered biological patterns such as sleep or attentiveness. Some may report synesthesia, increased intelligence,  and an increased ability to grasp abstract concepts.

Reported mechanisms
Not everyone agrees about what causes the reported NDE. Some believe the event is a peek into the the afterlife while others discount the experience as being caused by some form of artificial means discounting the afterlife aspect.

University of Montreal neuroscientist Mario Beauregard examined the brains of 15 people who reported near-death experiences. The participants relived their experiences while Beauregard completed the exam using electrodes and an isolation chamber. Beauregard noted there was a shift in their brain and the shift would allow these people to stay in touch with the spiritual world.

Auckland pyschiatrist Karl Jansen attributes NDEs to “underlying mechanisms in more mysterious realms that cannot currently be described." He does attribute NDEs partly to neurochemistry and psychology.

Neurologist Kevin Nelson believes NDEs are not imagined but lie within the brain itself. He attributes NDEs to Rapid Eye Movement (REM) state. Nelson also believes the NDE bright light is caused by visual stimulation in the brain due to the REM. The tunnel is also caused by a decrease of blood flow to theeye.

Mark Mahowald, director of the Minnesota Regional Sleep Disorders Center, believes there is nothing mysterious about NDEs. He attributes NDEs to oxygen starvation in the brain.

Laboratory-induced NDE
Recently, it has been established that the spectrum of effects attributed to near-death experiences can be fully reproduced, at will, by area-specific stimulation of the brain by magnetic resonance imaging techniques in combination with sensory deprivation.