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:

LinkedIn meets Tinder in this mindful networking app

Swipe right to make the connections that could change your career.

Getty Images
Sponsored
Swipe right. Match. Meet over coffee or set up a call.

No, we aren't talking about Tinder. Introducing Shapr, a free app that helps people with synergistic professional goals and skill sets easily meet and collaborate.

Keep reading Show less

In a first for humankind, China successfully sprouts a seed on the Moon

China's Chang'e 4 biosphere experiment marks a first for humankind.

Image source: CNSA
Surprising Science
  • China's Chang'e 4 lunar lander touched down on the far side of the moon on January 3.
  • In addition to a lunar rover, the lander carried a biosphere experiment that contains five sets of plants and some insects.
  • The experiment is designed to test how astronauts might someday grow plants in space to sustain long-term settlements.
Keep reading Show less

A world map of Virgin Mary apparitions

She met mere mortals with and without the Vatican's approval.

Strange Maps
  • For centuries, the Virgin Mary has appeared to the faithful, requesting devotion and promising comfort.
  • These maps show the geography of Marian apparitions – the handful approved by the Vatican, and many others.
  • Historically, Europe is where most apparitions have been reported, but the U.S. is pretty fertile ground too.
Keep reading Show less

Love in a time of migrants: on rethinking arranged marriages

Arranged marriages and Western romantic practices have more in common than we might think.

Culture & Religion

In his book In Praise of Love (2009), the French communist philosopher Alain Badiou attacks the notion of 'risk-free love', which he sees written in the commercial language of dating services that promise their customers 'love, without falling in love'.

Keep reading Show less