Near-death experiences tied to brain activity after death

ISLAMABAD: What happens when we actually die—when our heart stops and all electrical activity “flatlines” in our brain?

Humans have been asking this question since time immemorial. It’s a tough one because the dead do not normally ping back to us about the nature of their experiences. Religious texts are capable of supplying a multitude of explanations. But scientists have not given up on providing their own set of answers, and they are making some strides in better understanding the brain’s process of transitioning from life to death.

Most recently, this has become possible because of research that has monitored the brains of people who have been in the throes of actually dying. Some of these individuals have been able to report back about what they experienced. According to a US scientific magazine “The Scientific Magazine” and a report from CNN, the research of New York University Grossman School of Medicine revealed that the flatlined brains of some cardiac arrest patients burst into a flurry of activity during CPR, even though their heart stopped beating up to an hour. A small subset of study participants who survived were able to recall the experience, and one person was able to identify an audio stimulus that was played while doctors were trying to resuscitate them.

The researchers interpret the brain recordings they made of these patients as markers of “lucid, recalled experiences of death”—an observation that has “never been possible before,” says lead author Sam Parnia, an associate professor of medicine at NYU Langone Health and a longtime researcher of what happens to people as they die. “We’ve also been able to put forward a coherent, mechanistic explanation for why this occurs.”

“Recalled experiences of death”—a term Parnia prefers over “near-death experiences” for accuracy—have been reported across diverse cultures throughout recorded history. Some Western scientists previously dismissed such stories as hallucinations or dreams, but recently a few research teams have begun to pay more serious attention to the phenomena as a means to investigate consciousness and shine light on the mysteries of death.

In the new study, Parnia and his colleagues sought to find a biological signature of recalled experiences of death. They teamed up with 25 hospitals, primarily in the US and the UK Medical personnel used portable devices that could be placed on the heads of patients who were having a cardiac emergency to measure their brain oxygen levels and electrical activity without interfering with their medical treatment.

The researchers also tested for conscious and unconscious perceptions by placing headphones on patients that played a repeated recording of the names of three fruits: banana, pear and apple. In terms of unconscious learning, a person who does not remember hearing these fruit names but is asked to “randomly think of three fruits” may still give the right answer, Parnia says. Past research has shown, for example, that even people in a deep coma can unconsciously learn the names of fruits or cities if those words are whispered in their ear.

Between May 2017 and March 2020, 567 people suffered cardiac arrests at participating hospitals. Medical staff managed to gather usable brain oxygen and activity data from 53 of these patients, most of whom showed an electrical flatline state on electroencephalographic (EEG) brain monitors. But about 40 percent then experienced electrical activity that reemerged at some point with normal to near-normal brain waves that were consistent with consciousness. This activity was sometimes restored up to 60 minutes into CPR.

Of the 567 total patients, just 53 survived. The researchers conducted interviews with 28 of the survivors. They also interviewed 126 people from the community who had gone through cardiac arrests because the sample size of survivors from the new study was so small. Nearly 40 percent reported some perceived awareness of the event without specific memories attached, and 20 percent seemed to have had a recalled experience of death. Many in the latter group described the event as a “moral evaluation” of “their entire life and how they’ve conducted themselves,” Parnia says.

In their interviews with survivors, the researchers found that just one person was able to recall the names of fruits that had been played while they received CPR. Parnia acknowledges that this individual could have guessed the correct fruits by chance.