Speaker 1: Welcome to Unexplained Extra with me Richard McClane Smith, where
Speaker 1: for the weeks in between episodes, we look at stories
Speaker 1: and ideas that, for one reason another didn't make it
Speaker 1: into the previous show. In last week's episode, Death's Pale Flag,
Speaker 1: we explored the Haitian zombie myth through the seemingly miraculous
Speaker 1: story of Clavius Narcis. In nineteen sixty four, Clavius was
Speaker 1: declared dead by two separate doctors and subsequently buried underground,
Speaker 1: only to reappear in his home village eighteen years later
Speaker 1: very much alive. Some, thanks to the prevalence of the
Speaker 1: zombie myth in Haitian folklore, were convinced that Clavius had
Speaker 1: himself returned from death as a zombie. In nineteen eighty two,
Speaker 1: ethnobotanist Weighed Dave traveled to Haiti to investigate Clerviius's story.
Speaker 1: As it turned out, according to Davis, Clerviius was just
Speaker 1: one of many individuals who would have fallen victim to
Speaker 1: an apparent zombification process being carried out by voodoo priests
Speaker 1: in return for money. After analyzing a powder thought to
Speaker 1: have been used in this process, Wade found it to
Speaker 1: contain traces of tetrodotoxin, a potent neurotoxin extracted from pufferfish.
Speaker 1: Although even a small dose of tetrodotoxin is lethal to humans,
Speaker 1: with just the right amount, its effects, including severe paralysis
Speaker 1: and the slowing of the body's metabolic rate, can lead
Speaker 1: the recipient appearing clinically dead before they eventually recover from it.
Speaker 1: Could this thought Wade account for Clerviius's apparent resurrection, regardless
Speaker 1: of what exactly had happened. That Clerviius could ever have
Speaker 1: been declared dead in the first place raises a deeply
Speaker 1: un settling question. Just how exactly do we determine whether
Speaker 1: somebody has well and truly died. It may be surprising
Speaker 1: to discover that it isn't by any stretch an exact science.
Speaker 1: In years gone by, the death of a human individual
Speaker 1: was believed to have occurred simply when breathing had stopped
Speaker 1: or the heart was no longer beating. More recently, we
Speaker 1: have come to understand that absolute death comes only when
Speaker 1: the brain has irreversibly ceased to function. However, it wasn't
Speaker 1: until nineteen sixty eight that a definition of brain death
Speaker 1: previously referred to as irreversible coma, was first formalized according
Speaker 1: to the Harvard Medical School Committee that to find it.
Speaker 1: The process for confirming brain death is fourfold. First, the
Speaker 1: body's responsiveness is taken into consideration, whether even the most
Speaker 1: painful stimuli failed to elicit a reaction. Next, the body
Speaker 1: is monitored for signs of spontaneous movement and breathing. Does
Speaker 1: it require a ventilator to remain alive, for example. Thirdly,
Speaker 1: the body's reflexes will be assessed, most commonly by examining
Speaker 1: whether pupils respond to light or whether they are fixed
Speaker 1: and dilated. Finally, having taken all of that into account,
Speaker 1: an electroencephalogram or EEG should be used to test for
Speaker 1: any sign of brain activity. Only after all the correct
Speaker 1: criteria have been met could an individual be determined to
Speaker 1: have well and truly died. Although this definition has been
Speaker 1: refined somewhat since nineteen sixty eight, with today's modern fMRI
Speaker 1: scanners a far more sophisticated way to measure brain activity,
Speaker 1: the basic process for determining the death of an individual
Speaker 1: remains more or less the same. And yet, just as
Speaker 1: we used to think that a stopped heart or final
Speaker 1: breath was evidence of death. Might it also be the
Speaker 1: case that the criteria for supposed brain death could also
Speaker 1: one day prove to be an inadequate measure of a
Speaker 1: complete demise. Perhaps, just like in the days before we
Speaker 1: were able to measure brain activity, there might yet be
Speaker 1: some future more sophisticated technology to reveal the horrifying truth
Speaker 1: that brain death is in fact not a permanent, irreversible state.
Speaker 1: Could what appears to be a dead brain in fact
Speaker 1: still remain one with the potential to regain consciousness? Are
Speaker 1: you always taking care of your family? Do you often
Speaker 1: take care of others and not yourself? Now it's time
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Speaker 1: teladoc dot com slash Unexplained podcast. In early twenty nineteen,
Speaker 1: a team of neuroscientists from Yale School of Medicine, led
Speaker 1: by its Vonomere vi Celia and Stefano Danielli, published a
Speaker 1: remarkable paper in Nature which, although not providing proof by
Speaker 1: any stretch that an individual might recover consciousness from a
Speaker 1: supposed brain death, has nonetheless reignited the debate over just
Speaker 1: what is or isn't irreversible. It is well understood that
Speaker 1: reducing oxygen and blood flow to the brain can have
Speaker 1: rapid and devastating consequences. Just a few seconds without oxygen
Speaker 1: will result in a loss of consciousness. After five minutes
Speaker 1: a dino scene, triphosphate or atyp the body's primary source
Speaker 1: of cellular energy, will run out. If perfusion, the flow
Speaker 1: of blood and oxygen is not restored, a progressive and
Speaker 1: largely irreversible spiral of mechanical failure ensues from the build
Speaker 1: up of carbon dioxide to the emergence of enzymes that
Speaker 1: begin to break down the nerve tissue, which will lead
Speaker 1: inevitably to the death of the brain. Although in the past,
Speaker 1: individual cells taken from brains long after death have been
Speaker 1: shown to continue to function, performing processes such as making proteins.
Speaker 1: What Vesselia and Danielli's team wanted to know was could
Speaker 1: a whole brain be revived a number of hours after death.
Speaker 1: To test this out, researchers collected thirty two severed heads
Speaker 1: of pigs that had been slaughtered in an abatoir close
Speaker 1: to the team's laboratory. The brains, having been removed from
Speaker 1: the skulls, were then placed in a chamber and fitted
Speaker 1: with catheters. After waiting four hours from the moment of decapitation,
Speaker 1: each brain was given an EEG to confirm a flat
Speaker 1: line of brain activity before a warm substance containing nutrients
Speaker 1: and oxygen was slowly pumped into them. The system, known
Speaker 1: as brain X, developed especially for the experiment, is essentially
Speaker 1: a brain specific dialysis machine designed to mimic the original
Speaker 1: host's blood flow. Although they didn't expect the brains to
Speaker 1: regain consciousness, the team used a chemical agent in the
Speaker 1: solution to reduce the possibility of this happening. With the
Speaker 1: solution cycling through the brains, all the scientists had to
Speaker 1: do next was stand back and wait. After six hours
Speaker 1: of tests, the results were startling. As an experiment to
Speaker 1: test the efficacy of the brain X system, things could
Speaker 1: not have gone better, as almost complete circulation was restored
Speaker 1: to the brains. Blood vessels remained in such good shape
Speaker 1: throughout the experiment that they continued to function in the
Speaker 1: manner of a living brain. The system also succeeded in
Speaker 1: preserving the global structure of the brain. Tissue areas that
Speaker 1: are particularly susceptible to a lack of oxygen include the hippocampus,
Speaker 1: which plays a vital role in the consolidation of memories,
Speaker 1: were also well preserved. Comparing the solution as it flowed
Speaker 1: to and from the brains. Research has also discovered signs
Speaker 1: of metabolic activity as individual cells began to function again,
Speaker 1: generating carbon dioxide while absorbing glucose and oxygen. But most
Speaker 1: striking of all, when small slices of tissue were tested
Speaker 1: after treatment, the team discovered that at least some neurons
Speaker 1: remained capable of neural activity, a process thought fundamental for
Speaker 1: generating consciousness. As the team from Yale were keen to stress,
Speaker 1: their findings did not signify a resurgence of normal brain function. However,
Speaker 1: as others, including science journalist Sarah Reardon and the brain
Speaker 1: X team themselves have pointed out, since significant measures were
Speaker 1: taken to prevent this from happening, there is no knowing
Speaker 1: as yet what might have occurred under different circumstances, and
Speaker 1: even if the brain EX system was not enough to
Speaker 1: resurrect a consciousness from a dead brain, it would not
Speaker 1: be the end of the road for such a pursuit.
Speaker 1: It may be the case that some additional, as yet
Speaker 1: unknown action might be needed to kick start this into life.
Speaker 1: After all, only in nineteen forty seven, thanks to the
Speaker 1: Maverick instincts of cardiac surgeon Claude Beck, was it confirmed
Speaker 1: that an electrical shock could restart a human heart. Certainly,
Speaker 1: it remains to be seen if an individual's sense of
Speaker 1: consciousness could be restored after their brain has been declared
Speaker 1: clinically dead by today's standards. However, if history is anything
Speaker 1: to go by, that we haven't discovered yet how this
Speaker 1: might be achieved is no indication that it cannot be done,
Speaker 1: And with this comes some unsettling ideas just how much
Speaker 1: of a brain is required, or more specifically, how many
Speaker 1: of its constituent parts are necessary for a sense of
Speaker 1: consciousness and self awareness to emerge, even if we think
Speaker 1: not enough sections have been reactivated for this to occur.
Speaker 1: Might the brain be able to construct modes of conscious
Speaker 1: self awareness that we are not yet aware of and
Speaker 1: therefore wouldn't even know if they had been activated or not.
Speaker 1: And if, by some miracle it were possible to restore
Speaker 1: a sense of self awareness in a previously dead brain,
Speaker 1: whose self awareness would it be the individual that existed
Speaker 1: before death or something else, perhaps before we dismiss entirely
Speaker 1: the more alarming possibilities, As pointed out by the authors
Speaker 1: of a recent Comet piece about the remarkable brain X experiment,
Speaker 1: we might do well to ponder the wise word sub
Speaker 1: miracle Max from the nineteen eighty seven film The Princess Bride.
Speaker 1: There's a big difference between mostly dead and all dead.
Speaker 1: Mostly dead is also slightly alive. If you enjoy listening
Speaker 1: to Unexplained and would like to help support us, you
Speaker 1: can now go to Unexplained podcast dot com, Forward slash Support.
Speaker 1: All donations, no matter how large or small, are massively appreciated.
Speaker 1: All elements of Unexplained are produced by me, Richard McClain smith.
Speaker 1: Please subscribe and rate the show on iTunes, and feel
Speaker 1: free to get in touch with any thoughts or ideas
Speaker 1: regarding the stories you've heard on the show. Perhaps you
Speaker 1: have an explanation of your own you'd like to share.
Speaker 1: You can reach us online at Unexplained podcast dot com,
Speaker 1: or Twitter at Unexplained Pod and Facebook at Facebook dot com.
Speaker 1: Forward Slash Unexplained Now, it's time to take care of yourself.
Speaker 1: To make time for you, teledoc gives you access to
Speaker 1: a licensed therapist to help you get back to feeling
Speaker 1: your best. Speak to a licensed therapist by phone or
Speaker 1: video anytime between seven am to nine pm local time,
Speaker 1: seven days a week. Teledoc Therapy is available through most
Speaker 1: insurance or employers. Download the app or visit teledoc dot com,
Speaker 1: Forward Slash Unexplained Podcast Today to get started. That's t
Speaker 1: e ladoc dot com, slash Unexplained podcast