I survived two heart attacks in a matter of days in 2019, where either one should have killed me.
The myocardial infarctions (MIs) I suffered were called "widow makers" by the doctors because I had not one, not two, but three arteries that were 90% blocked. Paramedics revived me twice in the ambulance and a third time in the hospital. Their lifesaving efforts broke a couple of my ribs.
The fact that I didn't die at that time was a huge relief, but I was also disappointed. After reading for years about near death experiences (NDEs), I was saddened that when it came my time to slip the surly bonds of Earth, I saw nothing, felt nothing. I had no out-of-body experience, no familiar face to lead me to the pearly gates, no feelings of "peace and unity" with the universe that I can recall.
Ever since then, I've been on a quest to find out why some people experience NDEs while others evidently die without one. In fact, the whole process of dying has become of great interest to me. That may be because the end of the road is much closer than it used to be, but it's also because the process of dying is only now becoming a serious subject of scientific study.
"Despite NDE testimonies, the moments surrounding death largely remain a mystery to us, especially when it comes to the actual experience of dying," writes science writer Nate Scharping in Science Focus.
"But scientists have recently begun to explore what happens in the final moment of life by gathering data on brain activity from patients who are dying," Scharping says.
Using electroencephalogram (EEG) recordings, researchers can observe brain activity and how it changes up to the moments before death. The astonishing results they've achieved will change our perception of what happens during the process of death.
Note, I didn't say "time of death." As scientists have been demonstrating for the last decade or more, death does not occur when the heart stops beating or even when the brain stops working. Death is a process that happens over several minutes.
"Brain cells have a reserve of energy that allows them to keep functioning for a short time after blood flow has been cut off," Scharping says.
Dr Ajmal Zemmar, a neurosurgeon and neuroscientist in Louisville, says brain death doesn't happen until a minute or so after the heart stops.
When the brain stops receiving oxygen – a state known as hypoxia – a cascade of events is set in motion.
First is a heightened burst of activity as the brain responds to the lack of oxygen, likely representing an instinctual attempt to survive. Then there’s a period of lower-frequency brain wave activity, followed by an EEG flatline.
At some point during hypoxia, brain cells begin to die. This starts with a process known as depolarisation, where nerve cells lose their electrical charge. This prompts the brain to release neurotransmitter chemicals, as well as sodium, potassium and calcium ions, among other things.
This process could be responsible for the massive surge of activity seen in EEG readings of animal brains after death.
Zemmar refers to this as the “triphasic wave of death”: an EEG representation of neurons firing uncontrollably as they depolarise, like the neural equivalent of a fireworks finale.
Is this burst of electrical energy in the brain in the moments before death significant? The "heightened burst of activity as the brain responds to the lack of oxygen" is centered in the temporo-parietal-occipital areas of the brain; the parts of the brain that are typically associated with consciousness. Something is happening in our conscious mind when the brain realizes that death is near.
The findings defy conventional scientific wisdom. The mainstream belief was that “near death, the brain basically gave up,” says Dr Jimo Borjigin, a neuroscientist at the University of Michigan who led the study.
By contrast, her research shows that just before death, the brain is “hyper-activated” for a brief time, especially in the gamma domain.
The findings align with those from previous animal studies Borjigin conducted, leading her to suggest that the brain activity isn’t simply random or a false signal from some other part of the body.
"Her data includes evidence that areas of the brain related to memory are very active right before death, which aligns with reports of NDE survivors experiencing events from their lives, or seeing loved ones during their ‘final’ moments.
“Your family isn’t in front of you and your eyes aren’t open,” she says. “But somehow this hypoxia triggers a cascade of events that leads to memory recall.”
“Why would the brain devote so much energy just to give you memories that don’t seem to serve any immediate function?” Dr. Borjigin asks. “That’s a big question we’re still trying to address.”
Why study this subject at all? The mysteries surrounding death predate human civilization. Now, we have the tools, the machines, and the knowledge that can "demystify the dying process – offering comfort to those who have lost loved ones or are nearing death themselves – but might also help explain some of the puzzles of consciousness as well," writes Scharping.
Adding to the sum of knowledge about ourselves and our species is always a valuable exercise. As long as humans ask questions, science will try to answer them.
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