The Biggest Questions: What is death?

From MIT Technology Review:

Just as birth certificates note the time we enter the world, death certificates mark the moment we exit it. This practice reflects traditional notions about life and death as binaries. We are here until, suddenly, like a light switched off, we are gone.

But while this idea of death is pervasive, evidence is building that it is an outdated social construct, not really grounded in biology. Dying is in fact a process—one with no clear point demarcating the threshold across which someone cannot come back.

Scientists and many doctors have already embraced this more nuanced understanding of death. As society catches up, the implications for the living could be profound. “There is potential for many people to be revived again,” says Sam Parnia, director of critical care and resuscitation research at NYU Langone Health.

Neuroscientists, for example, are learning that the brain can survive surprising levels of oxygen deprivation. This means the window of time that doctors have to reverse the death process could someday be extended. Other organs likewise seem to be recoverable for much longer than is reflected in current medical practice, opening up possibilities for expanding the availability of organ donations.

To do so, though, we need to reconsider how we conceive of and approach life and death. Rather than thinking of death as an event from which one cannot recover, Parnia says, we should instead view it as a transient process of oxygen deprivation that has the potential to become irreversible if enough time passes or medical interventions fail. If we adopt this mindset about death, Parnia says, “then suddenly, everyone will say, ‘Let’s treat it.’”   

Moving goalposts 

Legal and biological definitions of death typically refer to the “irreversible cessation” of life-sustaining processes supported by the heart, lungs, and brain. The heart is the most common point of failure, and for the vast majority of human history, when it stopped there was generally no coming back. 

That changed around 1960, with the invention of CPR. Until then, resuming a stalled heartbeat had largely been considered the stuff of miracles; now, it was within the grasp of modern medicine. CPR forced the first major rethink of death as a concept. “Cardiac arrest” entered the lexicon, creating a clear semantic separation between the temporary loss of heart function and the permanent cessation of life. 

Around the same time, the advent of positive-pressure mechanical ventilators, which work by delivering breaths of air to the lungs, began allowing people who incurred catastrophic brain injury—for example, from a shot to the head, a massive stroke, or a car accident—to continue breathing. In autopsies after these patients died, however, researchers discovered that in some cases their brains had been so severely damaged that the tissue had begun to liquefy. In such cases, ventilators had essentially created “a beating-heart cadaver,” says Christof Koch, a neuroscientist at the Allen Institute in Seattle.

These observations led to the concept of brain death and ushered in medical, ethical, and legal debate about the ability to declare such patients dead before their heart stops beating. Many countries did eventually adopt some form of this new definition. Whether we talk about brain death or biological death, though, the scientific intricacies behind these processes are far from established. “The more we characterize the dying brain, the more we have questions,” says Charlotte Martial, a neuroscientist at the University of Liège in Belgium. “It’s a very, very complex phenomenon.” 

Brains on the brink

Traditionally, doctors have thought that the brain begins incurring damage minutes after it’s deprived of oxygen. While that’s the conventional wisdom, says Jimo Borjigin, a neuroscientist at the University of Michigan, “you have to wonder, why would our brain be built in such a fragile manner?” 

Recent research suggests that perhaps it actually isn’t. In 2019, scientists reported in Nature that they were able to restore a suite of functions in the brains of 32 pigs that had been decapitated in a slaughterhouse four hours earlier. The researchers restarted circulation and cellular activity in the brains using an oxygen-rich artificial blood infused with a cocktail of protective pharmaceuticals. They also included drugs that stopped neurons from firing, preventing any chance that the pig brains would regain consciousness. They kept the brains alive for up to 36 hours before ending the experiment. “Our work shows there’s probably a lot more damage from lack of oxygen that’s reversible than people thought before,” says coauthor Stephen Latham, a bioethicist at Yale University. 

In 2022, Latham and colleagues published a second paper in Nature announcing that they’d been able to recover many functions in multiple organs, including the brain and heart, in whole-body pigs that had been killed an hour earlier. They continued the experiment for six hours and confirmed that the anesthetized, previously dead animals had regained circulation and that numerous key cellular functions were active. 

“What these studies have shown is that the line between life and death isn’t as clear as we once thought,” says Nenad Sestan, a neuroscientist at the Yale School of Medicine and senior author of both pig studies. Death “takes longer than we thought, and at least some of the processes can be stopped and reversed.” 

A handful of studies in humans have also suggested that the brain is better than we thought at handling a lack of oxygen after the heart stops beating. “When the brain is deprived of life-sustaining oxygen, in some cases there seems to be this paradoxical electrical surge,” Koch says. “For reasons we don’t understand, it’s hyperactive for at least a few minutes.” 

In a study published in September in Resuscitation, Parnia and his colleagues collected brain oxygen and electrical activity data from 85 patients who experienced cardiac arrest while they were in the hospital. Most of the patients’ brain activity initially flatlined on EEG monitors, but for around 40% of them, near-normal electrical activity intermittently reemerged in their brains up to 60 minutes into CPR. 

Similarly, in a study published in Proceedings of the National Academy of Sciences in May, Borjigin and her colleagues reported surges of activity in the brains of two comatose patients after their ventilators had been removed. The EEG signatures occurred just before the patients died and had all the hallmarks of consciousness, Bojigin says. While many questions remain, such findings raise tantalizing questions about the death process and the mechanisms of consciousness. 

Life after death

The more scientists can learn about the mechanisms behind the dying process, the greater the chances of developing “more systematic rescue efforts,” Borjigin says. In best-case scenarios, she adds, this line of study could have “the potential to rewrite medical practices and save a lot of people.” 

Everyone, of course, does eventually have to die and will someday be beyond saving. But a more exact understanding of the dying process could enable doctors to save some previously healthy people who meet an unexpected early end and whose bodies are still relatively intact. Examples could include people who suffer heart attacks, succumb to a deadly loss of blood, or choke or drown. The fact that many of these people die and stay dead simply reflects “a lack of proper resource allocation, medical knowledge, or sufficient advancement to bring them back,” Parnia says.  

Borjigin’s hope is to eventually understand the dying process “second by second.” Such discoveries could not only contribute to medical advancements, she says, but also “revise and revolutionize our understanding of brain function.”

Link to the rest at MIT Technology Review

17 thoughts on “The Biggest Questions: What is death?”

  1. For most, death comes as the end of pain. Only 5% (I read somewhere) of those revived by CPR actually ever leave the hospital again. The process can be appallingly painful (all those people beating on your chest, cracking your ribs, determined to ‘give you a chance’ which is small. And the decisions made by whoever happens to be around or can be called in when you keel over on the street, not by a careful patient researcher.

    The aftermath of the resuscitations is non-trivial – and very, very expensive. Is it really the best allocation of scarce resources? When children starve worldwide for lack of a few dollars worth of protein? And will the electorate demand the state pay for it?

    Possibly this is the perspective of someone like me who has had to deal with chronic pain and disability for over three decades and I would feel differently if it were my child, and the effort brought them back for many years if they were in the right place at the right time.

    • Starvation today is a political issue. There is more than enough food to feed everybody. Defunding resuscitation in the US will do nothing for a kid in Somalia.

      • Enough food…for now.

        In addition to the matter of getting it to the right place because of politics there is the matter of hijacking shipments and, coming soon to a screen near you, fertilizer shortage famine.

        Globalization is on its last legs, two of the top food exporters are at war, and China has been hoarding food (guess why) and Brazil and Australia (big food exporters) are big fertilizer importers. (#1 by far and 5th). ’22 was a bumper crop, ’23, not so much.

        Guess what happens if the war goes on much longer.
        Nothing pretty.
        Oh, and Brazil is warning Venezuela to stay out of Guyana. Maduro isn’t listening.
        Been a while since the last War in SouthAm.

        Gobal Food concerns?
        Politics is the least of the threats.

        • Natural gas shortage —–> Fertilizer shortage. The US will have lots of both.

          Save the climate and starve. This was just tried in Sri Lanka.

          • Indeed.
            The US doesn’t need as much fertilizer as other countries (like most of Africa) and of the three main types it only imports one…from Canada.
            And on top of that the new forms of AI driven farming require but a tiny fraction of fertilizer and/pesticide.
            None of which applies to the most heavily populated countries in the world.

            We’re hanging on by a thread and the “bad actors” are making it worse.

            Two “funny” things about natural gas in the US:

            1- For all the gerontocracy’s efforts to reduce US production of fossil fuels (in favor of more expensive imports) market forces have propelled investment in refining the tools and techniques collectively referred to as “fracking” to the point US production cost is comparable to the Saudi and lower than everybody elses. Plus, getting a new well in place and producing takes months, not years. Big power in that scalability as OPEC just discovered. The more they cut production to try to raise prices, the more the US flows into the market.

            2- A recent development: Google of all outfits, is funding a production scale facility using fracking tech for, wait for it, geothermal energy production.


            So fracking not only provides fossil fuels, it also provides clean carbon free energy. How economically viable is tbd but if the numbers come together it will provide clean energy everywhere in the country, not just near hot springs; just drill a few miles down and flow water to drive a turbine 24×7. And as I pointed out, fracking wells can be put in place in months. If anything, the limiting factor will be the turbines and generators. We may end up using natural gas as only chemical feedstock and geopolitical leverage.

            Bottom line, we may get to zero carbon faster and cheaper through Big Energy than through the friends of the party getting all the subsidies.

            Techies gotta tech. Mess with them at your peril.

  2. Too close to the bone for me. Cancer kills impersonally. My dread is Alzheimer’s — the ability to watch from the inside and reflect upon the brain’s decay — using evanescent intellect to reflect upon intellectual capability as it vanishes, while trying to predict the details of the progress and its timeline. [What do you suppose those pigs thought? Too much like vivisection…]

    That’s not to say it isn’t a learning experience. To watch the degradation of the ability to read complicated choral music at tempo by discovering that there is so much short-term memory juggling going on to do it is to gain an understanding of just how the process works, by analyzing the dying skill. For example, the mental processes of music analyzed through reading for vocal performance are apparently quite different from those used to sing complex material from memory — different channels of some sort. (Perhaps evolutionarily so, the skills of vocalization being surely older than the required skills of reading.)

    If only I could buttonhole an actual researcher and suggest the addition of diagnostic tests just for musicians, on a par with the “Remember these seven words” or “Draw a clock face for 10 after 11”.

    • Agreed on Alzheimer’s.
      Stroke is next on the list.

      I had a bout of vertigo for a couple weeks a few years back that had all the symptoms of a micro-stroke.
      Turned out to be a vitamin D deficiency (go figure) but I learned a thing or two about myself.
      Nietzsche came to mind.

      • I would add mental illnesses and traumatic brain injuries to this list. I once had a case where a couple were married for over 20 years. They had a good marriage, but the man was in a car accident and suffered a TBI. It changed his personality to the point the woman divorced him, because he wasn’t safe to be around. Though his body was alive and walking, the man he had been was already dead.

        And another case where a couple married young, in their early twenties. Then around her twenty-fifth birthday, the woman was diagnosed with paranoid schizophrenia. Even decades later she was convinced her now-ex-husband was hiding listening devices in her womb. She made us promise we didn’t have listening devices in our offices. Interestingly, you’ll hear a lot of people say “my crazy ex,” but her former husband didn’t speak of her that way at all. Her illness robbed her of who she once was, and of someone she once loved, and who had loved her.

        The most tragic forms of death aren’t always bodily. I would like to see true cures for the mental types even before longevity treatments.

        • Indeed.
          Capgras Syndrome:

          Capgras delusion or Capgras syndrome is a psychiatric disorder in which a person holds a delusion that a friend, spouse, parent, another close family member, or pet has been replaced by an identical impostor. It is named after Joseph Capgras (1873–1950), the French psychiatrist who first described the disorder.

          The Capgras delusion is classified as a delusional misidentification syndrome, a class of delusional beliefs that involves the misidentification of people, places, or objects.[2] It can occur in acute, transient, or chronic forms. Cases in which patients hold the belief that time has been “warped” or “substituted” have also been reported.

          The delusion most commonly occurs in individuals diagnosed with schizophrenia but has also been seen in brain injury,[4] dementia with Lewy bodies,[5] and other dementia.[6] It presents often in individuals with a neurodegenerative disease, particularly at an older age.[7] It has also been reported as occurring in association with diabetes, hypothyroidism, and migraine attacks.[8] In one isolated case, the Capgras delusion was temporarily induced in a healthy subject by the drug ketamine.[9] It occurs more frequently in females, with a female to male ratio of approximately 3∶2.”

  3. The brain is but part of the story. Plumbing, really.
    Death is easy: There’s nobody home.
    The hard part is figuring out what is conciousness. Answer that and everything else falls into place.

    As Heinlein put it 75 years go: “when we die, do we die all over?”

    • Later in the book, after he has been gassed, Hamilton sees himself playing each person. Essentially being an Entity being each person, following the rules of the “game”. The implication in the story, was that he was dead. Then he “woke up” and forgot what he was “dreaming”.

      – That wasn’t a dream, he was dead for a brief moment and saw reality.

      Just as in Stranger in a Strange Land, Michael woke up from life, and was the Archangel Michael getting back to work.

      – That concept was a recurring theme in Heinlein’s stuff.

      Strange, I thought I posted this podcast before.

      Is Reality an Illusion? | Dr. Donald Hoffman | EP 387

      Look at 1:31:00 minutes, where he mentions how his work has impacted his life, and what comes after death. That he fully expects to take off his “headset” and laugh.

      – Essentially, Science is finding that Hoffman is right.

      One of Terry Pratchett’s first books was Strata, where he has an Entity that creates the universe and populates it with aspects of himself. The Entity is everyone.

      The movie The Nines, with Ryan Reynolds was the same concept of Reality being a game, and he was the creator of that game and simply forgot.

      In Doctor Sleep by Stephen King, Danny Torrance works in a facility, and helps people die. He tells them to go to sleep and they will wake somewhere else. He sees enough examples of people going away.

      This is all very old. I think that in the Hindu religion that the supreme god Brahma sleeps, dreams reality, then wakes and reality ends until he sleeps again.

      The majority of Hindus believe in one supreme god (The Brahman). Everything is a part of and a manifestation of Brahman, the ultimate reality; however, Brahman’s qualities and powers may be represented by a great diversity of gods/deities all of which emanate from The Brahman.

      The song Row, Row, Row your boat is right:

      – Life is but a dream.

      Edgar Alan Poe was right:

      The Alan Parsons Project – A Dream Within A Dream – Lyrics 1976

      “For my own part, I have never had a thought which I could not set down in words
      With even more distinctness than that with which I conceived it.
      There is, however, a class of fancies of exquisite delicacy which are not thoughts,
      And to which as yet I have found it absolutely impossible to adapt to language.
      These fancies arise in the soul, alas how rarely.
      Only at epochs of most intense tranquillity,
      When the bodily and mental health are in perfection.
      And at those weird points of time,
      Where the confines of the waking world blend with the world of dreams.
      And so I captured this fancy, where all that we see, or seem,
      Is but a dream within a dream.”

      Edgar Allan Poe

      This is a recurring theme in my stuff:

      – We are the Dreams, or the Nightmares, of that Entity which is this bubble of Reality that we live in.

      I feel the need for bongo drums to go along with what I am saying.

        • “An entity” is just sleight of hand, a placeholder saying: “Dunno.”

          HA! I use the word “Entity” because if I use the word “god” people impose their personal misconceptions on that word and it derails the conversation.

          Hoffman points out that everything is conscious. Listen to the podcast and you will see the discussion. What’s fun, is Peterson was imposing his limitations on what Hoffman was saying until the very last segment, and then he saw what Hoffman was saying, yet it was time to stop.

          It’s not that this is a “simulation”, it’s that everything is that “Entity”.

          I think the term pandeism, “everything is god”, comes closest to what they are finding.


          Read the first entry on the wiki page, it is a quote from Scott Adams’ book, God’s Debris. There are so many great Image/Seeds contained in that one page. There is quote after quote about pandeism. That all goes into my Story folders.

          The concept is at the heart of my stuff.

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