A scientific study answers. Do our memories really pass before our eyes through the throes of death?

You must have heard of "near-death" (NDES) experiences, those described by those returning to life after navigating critical moments while at recovery tables, some saying they watched their lives pass like a movie in front of their eyes, others met their dead and living loved ones, others went through experiences of separation from the body and watched doctors and nurses try to save them.

Many stories but to this day they remain unconfirmed hallucinations, especially since no one has returned from the dead to tell us the truth. Still, the details of the dying final moments seem more exciting than we thought, according to new research published in the Proceedings of the American Academy of Sciences (PNAS), in which scientists for the first time deliberately detected evidence of highly active consciousness in the brains of dying people, with patterns similar to those tracked in daydreaming and the intense process of retrieving memories.

What exactly happens in the brains of dying people?

Gamma waves range from 30 to 100 Hz and are the highest-frequency brainwaves and neural activity most common when people connect to their memory center in the brain's hippocampus. (Shutterstock)

After the heart stops and the living body is unable to breathe, the brain does not die instantly, on the contrary, there are minutes that pass between the cardiac arrest and the death of brain cells. Until recently, scientists didn't know exactly what was happening in those minutes, until the latest study detected powerful electrical waves rushing through the brain just before death, which makes you wonder if the dying process can activate the brain!

In her recently published paper, scientist Jimmo Burgegin, associate professor in the Department of Molecular and Integrative Physiology and the Department of Neurology at the University of Michigan, deliberately used an electroencephalometer (EEG) to figure out what happens in the brain during death compliance. The researchers obtained permission to monitor four dying patients, all of whom were in a coma following a cardiac arrest and had no hope of recovery. The experiment took place in the intensive care room, after it was decided to turn off the life support devices for the cases with the permission of their families.

After the ventilator was withdrawn, the hypoxia process induced a rise in heart rate and showed significant gamma wave activity in two patients. Brain oscillations are usually classified based on frequency and amplitude, and gamma waves range from 30-100 Hz, the highest frequency and neural activity most common when people connect to their memory center in the hippocampus of the brain. They are the waves responsible for the state of conscious perception, as high gamma activity is associated with the processes of memory, attention, learning, cognitive performance and information processing.

"The brains remained active for up to 300 seconds in a patient after the removal of the breathing stent, which is an unprecedented discovery," said Burgegin, author of the study, adding that what happens during those few seconds is the emanation of unusual electrical activity in a part known as the "hot zone" of the brain, which is the meeting point of the temporal, parietal and occipital lobe towards the back of the brain just behind the ear.

Increased activity of consciousness may be most powerful in healthy and young dying people. (Shutterstock)

When asked what this activity means for human consciousness, she added: "This activity has already been researched by other scientists in healthy humans, and has shown that it is associated with visual awareness, sensory perception, dreams and exitions from the body."

Although the four patients died, and there is no way to be sure of exactly what they witnessed, Borgijin's latest study points to an increasing state of awareness during the dying process. This state of consciousness may include recalling past memories, seeing lights or hearing sounds similar to those usually remembered by those who have experienced near-death.

It is worth noting that Borgegen began her research on the dying experiment in 2013, when a group of experimental mice were subjected to electroencephalometers during cardiac arrest, and the previous study showed an increase in the activity of "gamma" oscillations responsible for consciousness within the brains of 100% of the mice in question, and this activity lasted for up to 30 seconds after the cardiac arrest, which is almost the same result reached by Borgegen in her recent research on dying humans.

"In the case of the 2013 study, the mice in question were young and all healthy, unlike the recent study of people who were already sick and in a coma as a result of multiple heart attacks, which means that this increased activity of consciousness may be more powerful in healthy and young people," she told Meydan.

In dying. May your life flash before your eyes

Man recalls part of his life memories while dying, which is known as the "phenomenon of calling life." (Shutterstock)

In 2022, the sudden death of a Canadian man while undergoing a routine brain scan led to a group of doctors being able to accidentally capture unique data and monitor human brain activity while dying for the first time. The man was an 87-year-old man, and after his heart stopped during the examination, unusual activity in the brain electricity was observed.

During the examination, the researchers recorded about 900 seconds of brain activity before and after death, but focused their research efforts on the last 60 seconds, examining the 30 seconds before the patient's heart stopped supplying blood to the brain, in which they found that the brain followed the same neural patterns that it follows in cases of intense concentration, dreaming and memory recall, an activity that lasted for another 30 seconds after the patient's heart stopped beating.

The research team collected data on the different types of vibrations released by neurons, including Delta, Theta, Alpha and Beta waves, but they observed an unusual change in gamma wave activity within the patient's brain. This brain activity was the first concrete evidence that a man recalls part of his life memories while dying, which is known as the "life recall phenomenon."

Dr. Ajmal Zammar, author of the study and neurosurgeon at the University of Louisville in the United States, points out that this incident is the first experiment of its kind that provides scientific evidence for the process of retrieving memories in the last moments of life, but since it is the only case provided by the study at the time, and that the dying man was elderly and has epilepsy known for its effect on gamma wave activity, scientists were not sure of the prevalence of this phenomenon, especially with no way to confirm whether The man already sees and perceives his past memories or is he in a dream-like state due to his already disturbed nervous system.

So although the researchers made this amazing discovery in 2016, the report on the man's condition was not published until six years after his death, as they hoped to study more dying brains to support their claims, but they eventually gave up and published their study of the single case in the journal Frontiers in 2022.

Near-death experiences

Not all near-death experiences are happy, some can be frightening and characterized by pain, loneliness and hopelessness. (Shutterstock)

Renowned writer Ernest Hemingway described what happens while dying in a short story known as "The Snows of Kilimanjaro", which tells about a safari in which the hero suffers from gangrene and describes the moments of the soul's exit from the body as moments when the pain stops and one feels calm and peaceful. It was a simulation of the story of Hemingway himself being hit by a shell during World War I.

It is strange and interesting at the same time that what Hemingway told is the most accurate classic description of what was revealed in a report published in the American Science Journal (Scientific American) in 2020, and tells about the way the brain works during near-death experiences, as it indicates that the decrease in oxygen flow in the blood is usually associated with positive and joyful sensations, according to the reported experiments, and is not a cause for panic in most cases, which is considered a mystery and a puzzle.

According to the report, one in 10 patients with cardiac arrest in hospitals undergo such seizures, and survivors usually have a lot of stories and anecdotes about returning from the brink of death, which involve seeing and hearing unexplained things while losing consciousness, and interpreting them as access to the other world.

These experiences are mostly associated with the feeling of exiting the body or floating upwards, seeing bright light and feeling comfortable, although not all near-death experiences are happy, some can be frightening and characterized by pain, loneliness and hopelessness, but it seems that there are few who report such bad experiences. As for the fact that these experiences vary from person to person, the closest reason is that the mind tells the story formed by a person's experience, memory, and expectations.

There are about six minutes between the heart stopping beating and brain death. Then consciousness is lost and with it our ability to feel and perceive forever. (Shutterstock)

According to University of Copenhagen neurologist Daniel Kondzilla, the most likely scientific explanation for near-death experiences may be due to something resembling REM sleep, a condition in which the brain mixes wakefulness with dreaming states.

Condzilla argues that there is a fundamental difference between people who survived to report near-death experience and people who actually died, and that difference lies in the fact that the brains of those who survived did not lose their function permanently like others, so it is difficult to determine whether those who died went through the same subjective experiences or not.

According to Professor Guillaume Terry, a professor of cognitive neuroscience at Bangor University, there are about six minutes between the heart stopping beating and brain death, after which consciousness is lost and with it our ability to feel and perceive forever, and such experiences often occur in the time line between heart death and brain death.

One of the main limitations of studies looking at "near-death experiences," Terry says, is that they focus too much on the nature of the experiences themselves, often ignoring the context that precedes them. Terry says he's come across a number of theories that try to explain why life flashes before someone's eyes as their brain prepares to die, it could just be an artificial effect associated with a sudden rush of neural activity the moment the brain prepares to close, or it could be just a body's defense mechanism to overcome impending death, or it's a genetic reaction rooted in us. To be sure, research in this area is still scarce and limited, and that there's still a lot we don't know about what our brains experience in the few moments we transition from life to death.