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THE STUDY OF near-death experiences (or NDEs) is a fascinating, inherently divisive field, in which science and spirituality don’t so much as intersect as violently butt heads.

You’ve probably read the many reports of patients who, upon experiencing cardiac arrest and flatlining, have later been revived and are able to recall their death, what was happening in the emergency room, as well as reporting seeing tunnels of light, experiencing feelings of euphoria, warmth and love, sensations of floating above their hospital beds and highly detailed and incredibly specific reviews of their entire lives, along with encounters with deceased loves ones or divine beings.

Many who are revived are transformed by the experience. For some, it leads to a spiritual awakening, for others an affirmation of life, while many no longer fear death.

It’s worth defining what constitutes clinical death. In the case of heart failure, brain function declines rapidly, with brain waves flatlining within 11-20 seconds. At that point your brain is effectively an unplugged microwave. And yet, it’s at this point that researchers believe NDEs occur.

There is, of course, considerable disagreement over explanations for NDEs. Some point to them as proof of an afterlife, while others believe there are distinct neurological mechanisms that could account for the sensations and feelings commonly reported.

In that vein, a new study at NYU Grossman School of Medicine, found some survivors of cardiac arrest were able to describe lucid experiences that occurred while they were seemingly unconscious. In the study, four in 10 patients who survived, recalled some degree of consciousness during CPR not captured by standard measures.

The study also found that nearly 40 per cent of these patients had brain activity that returned to normal from a “flatline” state, even an hour into CPR, with the patients seeing spikes in gamma, delta, theta, alpha, and beta brain waves associated with higher mental function.

As mentioned earlier, resuscitated patients have long reported having heightened awareness and powerful, lucid experiences while unconscious. This new study found these experiences of death to be different from hallucinations, delusions, illusions, dreams, or CPR-induced consciousness.

So what the heck are they? The study authors hypothesise that the dying brain removes natural inhibitory (braking) systems. These processes may open access to “new dimensions of reality”, including lucid recall of all stored memories from early childhood to death (yep, including that time you roof-rocked a neighbour’s house on Christmas Eve), evaluated from the perspective of morality (damn). The idea of ‘life flashing before your eyes’ may literally be just that.

“Although doctors have long thought that the brain suffers permanent damage about 10 minutes after the heart stops supplying it with oxygen, our work found that the brain can show signs of electrical recovery long into ongoing CPR,” says study author Dr Sam Parnia, an associate professor at NYU Langone Health. “This is the first large study to show that these recollections and brain wave changes may be signs of universal, shared elements of so-called near-death experiences.”

Parnia adds, “These experiences provide a glimpse into a real, yet little understood dimension of human consciousness that becomes uncovered with death. The findings may also guide the design of new ways to restart the heart or prevent brain injuries and hold implications for transplantation.”

Does it settle the debate over whether an NDE offers a glimpse at a spiritual gateway or is ‘just’ a neurological fire drill? No, it doesn’t. The researchers conclude that research to date has neither proved nor disproved the reality or meaning of patients’ experiences and claims of awareness in relation to death. The truth, then, remains out there.

What is a near-death experience?

The term near-death experience was coined by psychiatrist Raymond Moody in his 1975 book, Life After Life and is used to describe a profound personal experience associated with death or impending death, which researchers describe as having similar characteristics. These experiences may encompass sensations including detachment from the body, feelings of levitation, serenity, security, warmth, joy, the experience of absolute dissolution, review of major life events, the presence of a light, and seeing dead relatives. Sometimes the experience is negative, with those experiences including sensations of anguish, distress, a void, devastation, emptiness, seeing hellish places and “the devil”.

NDEs usually occur during reversible clinical death.  In the US alone, an estimated nine million people have reported an NDE, according to a 2011 study in the Annals of the New York Academy of Sciences. Most of these near-death experiences resulted from serious injury that affects the body or brain. In a 2001 study of 344 patients who were successfully resuscitated in Dutch hospitals, 18 per cent reported an NDE.

What is the most famous near-death experience?

One of the most puzzling and frequently cited cases involves an American woman named Pam Thomas, who underwent brain surgery in 1991. Despite having her eyes taped shut and her ears blocked, upon waking she was not only able to describe an NDE but the bone saw used to cut into her skull.

How can the brain function after clinical death?

This is naturally a matter of heated debate among researchers. Parnia has previously stated that thoughts and consciousness may be possible as thought is a “fundamentally different entity” from the synaptic activity detected in brain cells. “From a scientific perspective, there’s not a single piece of evidence that demonstrates how brain cells could generate thoughts,” he says. “We [don’t] have the tools yet to measure it. That’s something for future generations of scientists.”

Others regard the idea of thoughts and consciousness devoid of a working brain as a matter of faith rather than science.

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