Lived life flashes before the eyes. The person himself may move in the tunnel towards the light, detach from his own body or encounter dead relatives.
Such experiences are reported by many who have been on the brink of death, and even 10–20 percent of cardiac arrest survivors. Medicine still knows the origin of the phenomenon poorly.
Researchers at the University of Michigan in the United States may have tracked down what happens in the brain on the verge of death.
Research team reports in the Pnas science journal that they observed sudden spikes in the brain activity of dying people after their hearts had stopped working.
Deadly is generally thought to mean the moment when the heart stops irreversibly.
However, based on research in recent years, the brain can continue to function for seconds or even hours after the heartbeat has stopped.
Neurologist Jimo Borjigin and his colleagues went through the medical records of four people from the moment of their death.
The patients had fallen into a coma and had no chance of surviving.
Doctors had installed EEG caps that measure the electrical activity of the brain on the patients’ heads before they were taken off the ventilators.
Waves appear in the electroencephalogram when a large number of neurons fire impulses at the same time.
Two of the four patients had sudden brain activity within seconds of being taken off ventilators.
The high-frequency gamma waves continued even after the hearts stopped working.
Gamma waves have been associated with recalling memories, learning, gathering information, perception and dreaming. Some researchers consider gamma waves to be a hallmark of consciousness.
They have two patients with abnormally strong brain waves at the time of death apparently had previous epileptic seizures.
They may have prepared the brain for abnormal rhythms, Borjig says For Science magazine.
During an epileptic fit, people can also have hallucinations and out-of-body experiences.
Researcher at New York University Sam Parnia offers an explanation for gamma waves in New Scientist magazine.
When a person dies, their oxygen levels drop, and this may turn off the brain’s “braking systems.”
Nerve pathways that are normally dormant can then be activated, which can be seen as abnormal electrical spikes.
Published in Tiede magazine 7/2023.
#Brain #Brain #waves #detected #moment #death
