We have all wondered what it is like to die. Resuscitation medicine can now revive people who have been clinically dead for hours, and some revived people tell riveting stories about the experience of dying and being dead. This opens up the opportunity to scientifically examine whether consciousness can exist independently of the body.
We often hear of near-death experiences and out-of-body experiences, purportedly experienced by people while clinically dead but who later recovered. Near-death experience accounts typically include an awareness of being dead, a sense of peace, passing through a dark tunnel towards a bright light, encountering a "being of light" and feeling unconditionally loved, reviewing one's life and deciding to return to the body. Science strongly suspects that near-death experiences and out-of-body experiences are hallucinations, occurring either before the heart stops or after it has been restarted
Dr Sam Parnia, director of resuscitation research at Stony Brook University, New York, illustrates the current state of resuscitation medicine with the following amazing story. A 30-year-old woman was found dead in a forest at 8.32am, in June 2011. Her body temperature had dropped from 37 degrees to 20, indicating she had been dead for several hours. An ambulance team administered CPR and defibrillation at 8.49am and she arrived in hospital at 9.22am, body temperature still 20 degrees, still dead.
CPR and chest compressions were continued, a breathing tube ventilated her lungs and her tissues were given optimal oxygen supply. Adrenalin and other drugs were used to restart her heart. Her temperature remained unchanged. After six hours, her temperature returned to 32 degrees and her heart restarted. Despite being dead for five to 10 hours overnight, and dead six hours in the hospital, she walked out of hospital three weeks later with no brain or organ damage.
You are declared clinically dead when your heart stops beating. Measurable brain activity shuts down within 40 seconds. Your body cells do not die immediately on your heart failing to supply them with oxygenated blood. Parnia estimates that bone cells can survive for four days, skin cells for one, and brain cells can remain viable but non-functioning for up to eight hours. Cooling the dead body slows cell deterioration, allowing physicians to safely reverse the cellular processes that occur and avoiding brain damage.
Resuscitation medicine now makes objective studies of near-death experiences and out-of-body experiences possible. A large-scale study called Aware (awareness during resuscitation), involving 2,060 patients who suffered cardiac arrest (330 survived), was launched in 2008, with Parnia as lead investigator. A range of mental experiences in relation to death were tested for validity using objective markers to determine if near-death experiences and out-of-body experiences are real or hallucinatory. The results were published online in the journal Resuscitation in October.
Thirty-nine per cent of patients who survived described awareness, but not explicit recall of events, while they were clinically dead. Twenty per cent said they felt unusually peaceful. Some saw a bright light, others felt fearful or felt they were drowning. Thirteen per cent felt separated from their bodies and 13 per cent said their senses were heightened. Nine per cent had experiences compatible with near-death experiences. Only 2 per cent reported out-of-body experiences: that is, full awareness, with recall of seeing and hearing events. One man recalled leaving his body and watching from the corner of the room for several minutes as the medical staff worked to resuscitate him, accurately recounting their actions. These experiences were apparently recorded during a period when he had neither a heartbeat nor brain activity.
Although this study indicates that awareness may persist after the brain has shut down, it neither proves nor disproves the reality or meaning of the patients’ claims of awareness.
The out-of-body incident is interesting but far short of convincing; the recollections could be memories of a TV documentary, for example, seen by the patient when he was hale and hearty. Much more tightly controlled research is needed.
Watertight demonstrations of out-of-body experiences, should they ever come, indicating that consciousness can exist independently of a functioning brain, would certainly put the non-material cat among the material pigeons.