The last memories of the brain: the mysterious waves emitted during death

What happens in the brain of a dying person? It is a question that fascinates and frightens at the same time, as it touches the very essence of our existence. If some testify to having seen their life pass before their eyes during an imminent death experience, what is really the brain activity at the time of death?

A new study, published in the journal Frontiers in Aging Neuroscience, sheds new light on this subject. Researchers have managed to record for the first time the brain waves of an 87-year-old epileptic patient who died of a heart attack. Thanks to an electroencephalogram, they were able to observe the 30 seconds which followed the stopping of the heart.

Their discovery is surprising: instead of gradually fading, the brain emitted a significant increase in a particular type of wave, called gamma oscillations. These waves are involved in processes such as dreaming, meditation and memory recall. They are also associated with intense mental activity, such as during a complex calculation or a game of chess.

According to the study authors, these gamma oscillations may reflect late recall of important life events, similar to that reported in near-death experiences. “By generating oscillations involved in memory retrieval, the brain can play a last recall of important life events just before death,” says Dr. Ajmal Zemmar, lead author of the study.

These results suggest that the brain may retain coordinated activity after blood has stopped flowing through it. Similar observations had previously been made in rats, but this is the first time they have been detected in humans. However, we must remain cautious, because this is a single case, and the patient had an injured brain and epilepsy.

This research opens up new perspectives on understanding the exact moment when life ends and raises ethical questions, particularly related to the removal of organs for transplantation. They also invite us to reconsider our relationship to death and to our loved ones who are leaving us. “One thing we can learn from this research is this: Although our loved ones have their eyes closed and are ready to leave us, their brains may be replaying some of the most beautiful moments of their lives,” concludes Zemmar.