It is the great mystery of humanity: What happens to us when we die? Scientists are just as fascinated by a slightly different question: What happens to us when we are dying? According to the latest research, quite a lot.
Editor’s note: When there isn’t a big headline making news, we often pick a Big Story on a topic that we think will be interesting to you. We’d be just as happy to take requests from you. Do write to us at talktous@splainer.in. We’d also love to hear what you think of our leads on these kinds of less-newsy stories on the complicated truth about narcissism, ‘philanthropy’ of the very rich, and the problem with pandas.
Researched by: Nirmal Bhansali
The definition of death
Cardiac arrest: The clinical definition of death occurs when the heart stops pumping blood—which is called cardiac arrest. Not to be confused with a heart attack—where there is a blockage but the heart is still pumping. Moments after a cardiac arrest, the brain and other organs lose oxygen. And all activity stops—what we know as ‘brain death’.
Today, the irreversible loss of brain function is necessary to pronounce someone dead. This is how it supposedly occurs:
When the brain is starved of blood flow (ischemia) and oxygen (anoxia), the patient faints in a fraction of a minute and his or her electroencephalogram, or EEG, becomes isoelectric—in other words, flat. This implies that large-scale, spatially distributed electrical activity within the cortex, the outermost layer of the brain, has broken down. Like a town that loses power one neighborhood at a time, local regions of the brain go offline one after another.
Except it isn’t so neat and tidy. Dying is a very active and complicated business. And it can take a long time.
Death as a process: For centuries, human beings have viewed death as an event. But modern science has taught us it is, in fact, a process. Life doesn’t end with cardiac arrest:
After cardiac arrest, blood and oxygen stop circulating through the body, cells begin to break down, and normal electrical activity in the brain gets disrupted. But the organs don’t fail irreversibly right away, and the brain doesn’t necessarily cease functioning altogether.
We made this discovery thanks to the medical science of resuscitation. Today, we restart the heart, reverse cell death—and even restore brain function. Our ability to reverse death has in turn enabled what all of us know as Near Death Experiences aka NDE—which have become more common, and therefore studied in greater detail.
What is a Near Death Experience, anyway?
There isn’t a tidy definition of what constitutes an NDE. But they usually occur after life-threatening episodes—most often involving cardiac arrest. They have become more common with scientific advances—and more compelling:
It is no longer unheard of for people to be revived even six hours after being declared clinically dead. In 2011, Japanese doctors reported the case of a young woman who was found in a forest one morning after an overdose stopped her heart the previous night; using advanced technology to circulate blood and oxygen through her body, the doctors were able to revive her more than six hours later, and she was able to walk out of the hospital after three weeks of care.
We come back from the dead a lot more than any time in history.
Data point to note: One in 10 people claims to have had an NDE after cardiac arrest—that adds up to roughly 800 million worldwide “who may have dipped a toe in the afterlife.”
The happy, shiny version: The scientific quest to study NDEs starts in 1975 with Raymond Moody—who wrote a bestselling book based on the NDEs of 150 people. All of them tell the same story:
The narrative arc of the most detailed of those reports – departing the body and travelling through a long tunnel, having an out-of-body experience, encountering spirits and a being of light, one’s whole life flashing before one’s eyes, and returning to the body from some outer limit-– became so canonical that the art critic Robert Hughes could refer to it years later as “the familiar kitsch of near-death experience.”
Over time, NDEs would become more elaborate:
These include heightened sensitivity to light, sound, and certain chemicals; becoming more caring and generous, sometimes to a fault; having trouble with timekeeping and finances; feeling unconditional love for everyone, which can be taxing on relatives and friends; and having a strange influence on electrical equipment.
Point to note: At least 23% of reported experiences are unpleasant—but they are studiously ignored by pop culture. These include “a complete nightmare view of death, with humans being tortured and a painful afterlife”or—“an empty void, spending the rest of your eternity floating around aimlessly.” Yikes!
Enter: The scientists of death
Moody’s book opened the door to a flood of researchers eager to study the science of death. According to Alex Blasdel in The Guardian, the scientific community can be divided into three camps. One: Spiritualists who view NDEs as encounters with the divine. Moody fell squarely in this camp:
As researchers, the spiritualists’ aim was to collect as many reports of near-death experience as possible, and to proselytise society about the reality of life after death. Moody was their most important spokesman; he eventually claimed to have had multiple past lives and built a “psychomanteum” in rural Alabama where people could attempt to summon the spirits of the dead by gazing into a dimly lit mirror.
The other two were more closely aligned with the science—rather than the spirituality of death. These are the physicalists and parapsychologists.
The parapsychologists: are intent on proving that there is indeed a human consciousness—that exists independently of the brain:
That is a key tenet of the parapsychologists’ arguments: if there is consciousness without brain activity, then consciousness must dwell somewhere beyond the brain. Some of the parapsychologists speculate that it is a “non-local” force that pervades the universe, like electromagnetism. This force is received by the brain, but is not generated by it, the way a television receives a broadcast.
They use the protocols and standards of medical research to prove their hypothesis. And their research has been published in a variety of respected journals.
The quest for veridical perception: Parapsychologists have focused on a category of ‘proof’ called “apparently nonphysical veridical perception.” This means the person sees or hears something they should not have been able to—what we understand as an “out-of-body experience.” And here’s why:
As the only stage in an NDE that involves perceiving the physical rather than the spiritual world, an out-of-body experience has the most potential to convince sceptics. If you could prove that someone saw or heard things that brain science says they could not have seen or heard, you would have, at the very least, evidence that our understanding of the brain is even more incomplete than we thought, and at most, a sign that a conscious mind can exist apart from a living body.
The most cited example: is that of Pam Reynolds who underwent surgery to remove a brain aneurysm. The doctors put her into “hypothermic cardiac arrest”—and her brain was completely inactive. Yet Reynolds accurately remembered what was happening in the OR—including instruments, conversations and even the unkind song playing on the stereo–’Hotel California’ (“You can check out any time you like, but you can never leave”).
The physicalists: are not interested in anything outside the human body—nor do they believe in its existence. Physicalists want to understand the biology of death. What happens to our body—especially our brain—as we die. But what they’ve found is no less fascinating.
Meet Patient One: She represents the ultimate riddle of death for the physicalists. She collapsed during pregnancy, and soon fell into a coma. The family decided to pull the life support. But when the oxygen was turned off, the brain did not die within seconds—as expected. Instead it went into “overdrive”:
In the moments after Patient One was taken off oxygen, there was a surge of activity in her dying brain. Areas that had been nearly silent while she was on life support suddenly thrummed with high-frequency electrical signals called gamma waves. In particular, the parts of the brain that scientists consider a “hot zone” for consciousness became dramatically alive. In one section, the signals remained detectable for more than six minutes. In another, they were 11 to 12 times higher than they had been before Patient One’s ventilator was removed.
We don't know what she experienced because Patient One did not survive. But doctors say it proves death may contain more life than we ever thought possible. Why this matters: “understanding the neurophysiology of death can help us to reverse it.”
Point to note: Physicalists are not to be confused with scientists who simply view NDEs as a coping mechanism of a body at a time of extreme shock. For these sceptics, the out-of-body experiences, intense joy, feeling of transcendence etc. sound a lot like a brain on LSD. It’s simply what it does when exposed to a set of circumstances.
The bottomline: The science of death—at the very least—promises that one day we will journey deeper than ever into the land of the dead to bring our loved ones back—like Savitri reviving her Satyavan. We leave the last word to Gideon Lichfield in The Atlantic:
All of this makes NDEs perhaps the only spiritual experience that we have a chance of investigating in a truly thorough, scientific way. It makes them a vehicle for exploring the ancient human belief that we are more than meat. And it makes them a lens through which to peer at the workings of consciousness—one of the great mysteries of human existence, even for the most resolute materialist.
Reading list
The Guardian’s deep dive into the emerging study of death is a must-read. This 2015 feature from The Atlantic (splainer gift link) looks at the science behind Near Death Experiences. Scientific American focuses on brain activity during NDEs while BBC ScienceFocus looks at the varied experiences of NDEs.
