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In many film and television works, people always flash back many important moments in their lives before they die, which are touching and tearful. But do you believe it? There will really be a "walking lantern" in the last few minutes of life.

(photo: freepik) little has been known about the changes in the brain before and after cardiac arrest, and the "near-death experience" is both dangerous and mysterious.

Studies and reports on near-death experiences can be traced back hundreds of years. In 1740, a French doctor described a near-death experience in his book Anecdotes de M é decine, which is considered to be an early record.

At that time, people relied heavily on theology, so the experiences of near-death experiences were endowed with mystery. The patient recorded in the book temporarily lost consciousness, then saw a pure and bright light, and he thought he must have ascended to heaven.

(photo source: GIPHY) as there are more and more cases of near-death experiences, people have discovered something in common, and seeing light is one of them. In addition, there are soul out of the body, into the tunnel, feeling calm and happy, and life review and so on.

The most common reaction is that the patient has an abnormal perception of time, thinks very fast, and feels that the soul is flying out of the body.

This series of reactions is very similar to something we experience almost every day-dreaming. Dreams usually occur during REM sleep, when we lie in a quiet bedroom, paralyzed, but feel omnipotent.

One second he was a humble cubicle beater, and the next he traveled to the Amazon rainforest to look for Mayan relics (photo: GIPHY-DREAM CORP LLC). Scientists have found that when dying, the activity of the temporal-parietal-occipital junction (TPO) in the brain is indeed similar to that of dreaming.

It is generally believed that as the heart stops beating, the brain's activity decreases little by little until it is completely quieted down. However, more and more studies have found that there is a strong oscillation of brain waves before and after the heart stops beating.

In 2013, Jimo Borjigin, a neuroscientist from the University of Michigan, studied brain activity in experimental rats after cardiac arrest and found that a gamma wave nerve oscillation was released in the brain for the first 30 seconds.

The frequency of this neural oscillation is relatively high, usually during the transition from waking consciousness to meditative consciousness, or during REM sleep. It is thought to be a kind of brain wave associated with long-term memory, complex thinking and cognition, especially in the TPO area.

(photo Source: wiki) in a new study by Mo Bolzikin's team, they investigated four dead patients who used EEG to detect brain activity. Two of them experienced a surge in gamma waves after cardiac arrest, which lasted for a few minutes, sometimes "ridiculously high".

In this study, both patients with a surge in gamma waves had had epilepsy, but it was not possible to speculate whether the history of epilepsy had a permanent effect on their brains, causing them to have such violent nerve oscillations when they were dying.

At present, it is believed that the active gamma wave in TPO area is a sign of near-death experience, which means that patients may be conscious at this moment, and they feel something independent of their real environment.

(photo source: GIPHY-Percolate Galactic) it is a mystery why there is a near-death experience and why the brain has a nervous oscillation at the time of death.

Neuroscientists from the Federal Institute of Technology in Lobsang, Switzerland, have explained from the perspective of neuroanatomy that they divide near-death experiences into two types:

Type 1 near-death experience is characterized by a sense of experience outside the body, a change in the sense of time, thinking that you are flying, or exercising very lightly. They believe that this is mainly due to brain damage in the right hemisphere, which affects the right temporal-parietal lobe connection.

Type 2 near-death experience is characterized by seeing glowing people, having a real sense of existence, and hearing voices. The reason for this series of experiences is brain injury in the left hemisphere, which affects the left temporal-parietal junction.

(photo Source: wiki-DBCLS) scientists believe that damage to the bilateral occipital cortex is responsible for strange visual experiences, while damage to the hippocampus and amygdala in the temporal lobe, which is responsible for memory or emotion, can lead to memory flashbacks and mood swings.

Due to the lack of actual data, scientists can only use models to speculate about what happens in our brains when we are dying.

In modern times, death requires irreversible loss of brain function, that is, during cerebral ischemia and hypoxia, the patient loses consciousness and the EEG returns to a straight line.

This means that activity in various areas of the cerebral cortex gradually calms down, and these areas, like the fading lights in the building, are cut off one by one.

(photo: GIPHY) this state caused by ischemia or hypoxia causes people to have all kinds of strange sensations. Researchers once asked people who had reported near-death experiences to do a questionnaire describing near-death events and what actually happened at about the same time.

It turns out that compared with the real situation, these people have more vivid memories of their near-death experiences and are rich in details, which can be said to be "more real than real".

Among the many doubts about near-death experiences, what is very puzzling is the euphoria caused by lack of oxygen or ischemia.

It feels a bit like you are sitting in a speeding car, next to the open window, and the wind makes you a little breathless but inexplicably happy.

Some people think that this is a psychological protective mechanism, because the process is so painful that the brain wants to create a beautiful illusion to allow itself to die happily (or at least peacefully) at the end.

(photo source: BlueWillow) anyway, let's accumulate more wonderful moments for Walking Horse Lantern.

Reference:

[1] Xu G, Mihaylova T, Li D, Tian F, Farrehi PM, Parent JM, Mashour GA, Wang MM, Borjigin J. Surge of neurophysiological coupling and connectivity of gamma oscillations in the dying human brain. Proc Natl Acad Sci U S A. 2023 May 9: 120 (19): e2216268120. Doi: 10.1073/pnas.2216268120.

[2] Borjigin J, Lee U, Liu T, Pal D, Huff S, Klarr D, Sloboda J, Hernandez J, Wang MM, Mashour GA. Surge of neurophysiological coherence and connectivity in the dying brain. Proc Natl Acad Sci U S A. 2013 Aug 27: 110 (35): 14432-7. Doi: 10.1073/pnas.1308285110.

[3] https://www.livescience.com/46993-oldest-medical-report-of-near-death-experience.html

[4] https://www.livescience.com/65838-near-death-experiences-rem-sleep.html

[5] https://www.smithsonianmag.com/smart-news/surging-brain-activity-in-dying-people-may-be-a-sign-of-near-death-experiences-180982106/

[6] https://www.newscientist.com/article/2371316-brain-activity-of-dying-people-shows-signs-of-near-death-experiences/

[7] https://www.scientificamerican.com/article/what-near-death-experiences-reveal-about-the-brain/

This article is from the official Wechat account: bring Science Home (ID:steamforkids), author: everything Magazine

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