from the world's big
After death, you’re aware that you’ve died, say scientists
Some evidence attributes a certain neurological phenomenon to a near death experience.
Time of death is considered when a person has gone into cardiac arrest. This is the cessation of the electrical impulse that drive the heartbeat. As a result, the heart locks up. The moment the heart stops is considered time of death. But does death overtake our mind immediately afterward or does it slowly creep in?
Some scientists have studied near death experiences (NDEs) to try to gain insights into how death overcomes the brain. What they've found is remarkable, a surge of electricity enters the brain moments before brain death. One 2013 study out of the University of Michigan, which examined electrical signals inside the heads of rats, found they entered a hyper-alert state just before death.
Scientists are beginning to think an NDE is caused by reduced blood flow, coupled with abnormal electrical behavior inside the brain. So the stereotypical tunnel of white light might derive from a surge in neural activity. Dr. Sam Parnia is the director of critical care and resuscitation research, at NYU Langone School of Medicine, in New York City. He and colleagues are investigating exactly how the brain dies.
Our cerebral cortex is likely active 2–20 seconds after cardiac arrest. Credit: Getty Images.
In previous work, he's conducted animal studies looking at the moments before and after death. He's also investigated near death experiences. “Many times, those who have had such experiences talk about floating around the room and being aware of the medical team working on their body," Dr. Parnia told Live Science. “They'll describe watching doctors and nurses working and they'll describe having awareness of full conversations, of visual things that were going on, that would otherwise not be known to them."
Medical staff confirm this, he said. So how could those who were technically dead be cognizant of what's happening around them? Even after our breathing and heartbeat stops, we're conscious for about 2–20 seconds, Dr. Parnia says. That's how long the cerebral cortex is thought to last without oxygen. This is the thinking and decision-making part of the brain. It's also responsible for deciphering the information gathered from our senses.
According to Parnia during this period, "You lose all your brain stem reflexes — your gag reflex, your pupil reflex, all that is gone." Brain waves from the cerebral cortex soon become undetectable. Even so, it can take hours for our thinking organ to fully shut down.
Usually, when the heart stops beating, someone performs CPR (cardiopulmonary resuscitation). This will provide about 15% of the oxygen needed to perform normal brain function. "If you manage to restart the heart, which is what CPR attempts to do, you'll gradually start to get the brain functioning again," Parnia said. “The longer you're doing CPR, those brain cell death pathways are still happening — they're just happening at a slightly slower rate."
CPR may help retain some brain function for longer. Credit: Getty Images.
Dr. Parnia's latest, ongoing study looks at large numbers of Europeans and Americans who have experienced cardiac arrest and survived. "In the same way that a group of researchers might be studying the qualitative nature of the human experience of 'love,'" he said, "we're trying to understand the exact features that people experience when they go through death, because we understand that this is going to reflect the universal experience we're all going to have when we die."
One of the objectives is to observe how the brain acts and reacts during cardiac arrest, through the process of death, and during revival. How much oxygen exactly does it take to reboot the brain? How is the brain affected after revival? Learning where the lines are drawn might improve resuscitation techniques, which could save countless lives per year.
"At the same time, we also study the human mind and consciousness in the context of death," Parnia said, “to understand whether consciousness becomes annihilated or whether it continues after you've died for some period of time — and how that relates to what's happening inside the brain in real time."
For more on the scientific perspective on a near death experience, click here:
Join the legend of non-fiction in conversation with best-selling author and poker pro Maria Konnikova.
China moves to Russia and India takes over Canada. The Swiss get Bangladesh, the Bangladeshi India. And the U.S.? It stays where it is.
What if the world were rearranged so that the inhabitants of the country with the largest population would move to the country with the largest area? And the second-largest population would migrate to the second-largest country, and so on?
Andy Samberg and Cristin Milioti get stuck in an infinite wedding time loop.
- Two wedding guests discover they're trapped in an infinite time loop, waking up in Palm Springs over and over and over.
- As the reality of their situation sets in, Nyles and Sarah decide to enjoy the repetitive awakenings.
- The film is perfectly timed for a world sheltering at home during a pandemic.
Most of Stonehenge's megaliths, called sarens, came from West Woods, Wiltshire.
Discovering Stonehenge's signature<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzUyOTYyMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0MzQ2NDc3Nn0.zb-izy2gdpzY5RboUnWumoX1XqP7WgqqkfANYnMkRSA/img.jpg?width=1245&coordinates=0%2C726%2C0%2C-4&height=700" id="a041b" class="rm-shortcode" data-rm-shortcode-id="9872216ca30ec9e5628b8e91f32b5b6b" data-rm-shortcode-name="rebelmouse-image" />
In 1958, engineers undertook the task of re-erecting a Stonehenge trilithon that fell in 1797. Three cores drilled into a sarsen disappeared soon after.
For every answer, another question<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzUyOTYyNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTU5NzI5NDEzNX0.iNRlen_VApo2Hw6SPd_eiVodaG3UpEb00yD4GX_9JgU/img.jpg?width=1245&coordinates=0%2C164%2C0%2C1&height=700" id="e4fe1" class="rm-shortcode" data-rm-shortcode-id="157f21a6e304f7f50ebec55e2e53e505" data-rm-shortcode-name="rebelmouse-image" />
A view of Stonehenge during the Summer Solstice.
(Photo: Wikimedia Commons)<p>Thanks to Nash and his team, scientists now know the source of Stonehenge's sarsens. This clue can help them solve other Stonehenge mysteries. That most of the stones were sourced from one location, the study notes, suggests that they were erected at about the same time. It also reveals the routes the Neolithic builders had to traverse with their heavy loads.</p><p>But questions remain. Why did the builders choose West Woods when the Salisbury Plain is dense with sarsen? Why were two megaliths (Stones 26 and 160) sourced elsewhere? And were the missing stones gathered from West Woods or elsewhere? </p><p>These questions only touch on the sarsens. The question that intrigues so many of the monument's visitors remains hotly debated: Who built Stonehenge and why? Was it a <a href="https://www.theguardian.com/science/2013/mar/09/archaeology-stonehenge-bones-burial-ground#:~:text=Stonehenge%20may%20have%20been%20burial%20site%20for%20Stone%20Age%20elite%2C%20say%20archaeologists,-This%20article%20is&text=Centuries%20before%20the%20first%20massive,a%20theory%20disclosed%20on%20Saturday." target="_blank">burial site for the Stone age elite</a>? <a href="https://www.sciencedaily.com/releases/2012/06/120622163722.htm" target="_blank">A monument marking British unification</a>? <a href="https://www.theguardian.com/science/2015/mar/15/circular-thinking-stonehenges-origin-is-subject-to-new-theory" target="_blank">A Druid Mecca</a>? We don't know, but as scientific tools advance, we may be able to break the prehistoric silence that has laid over Stonehenge for so long.</p>