What happens to the brain in those moments between life and death – like immediately after a cardiac arrest? While various movies and television shows have ventured into supposing on this “flatliner” status the human body goes into, researchers are looking into the hard science of this in-between.
During a cardiac arrest, the electrical signals that make the heart pump are interrupted, causing the heart to stop beating, according to the American Heart Association. Death follows shortly after this. In the majority of fatal cases, doctors medically define death as when the heart is no longer beating, Live Science reports.
Dr. Sam Parnia, director of critical care and resuscitation research at NYU Langone School of Medicine in New York City, said,
Technically speaking, that’s how you get the time of death — it’s all based on the moment when the heart stops.
When this happens, blood is no longer circulating to the brain, meaning brain functions stops “almost immediately,” Parnia explained. “You lose all your brain stem reflexes — your gag reflex, your pupil reflex, all that is gone.”
Parnia and colleagues are studying consciousness after death, examining groups of people in Europe and the United States who have suffered cardiac arrest. Parnia said, “In the same way that a group of researchers might be studying the qualitative nature of the human experience of ‘love,’ for instance, 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.”
The team is observing what happens to the brain during cardiac arrest, death and revival via CPR, to understand how much oxygen is getting to the brain in those moments, and when the brain’s cortex comes “back online.”
Their focus is finding more accurate methods of monitoring the brain from the threshold of death, and looking for better ways to resuscitate people whose hearts have stopped. “At the same time, we also study the human mind and consciousness in the context of death, 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,” Parnia said.