What happens to the brain at the time of death

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

Why do people leave the body, fall into a dark tunnel and see deceased relatives.

People who have been on the verge of life and death always tell about the same thing: a person slides along a dark tunnel to a bright light at the end, a feeling of absolute peace and happiness envelopes him, he hears pleasant music, soft light envelops him from all sides. Often people describe their way out of the body: they see themselves from the outside and feel a sense of floating.

Those who have received near-death experience (NDE) sincerely believe in the reality of their experiences and use them as proof of the existence of the soul and life after death. However, neurophysiologists suggest that all of the effects of NDE are due to the dying brain.

What happens to the brain after cardiac arrest

Using electrodes inserted into the brains of patients, neurologists have found that even after the heartbeat stops, the nerve cells in the brain continue to function.

Death is marked by the final wave of electrical activity in the brain. This wave begins 2–5 minutes after oxygenated blood ceases to flow to the brain and displays dangerous neural changes that lead to irreversible damage.

A short burst of activity was also found in an earlier study. Scientists performed electroencephalography (EEG) on dying people and found that blood pressure loss is followed by a temporary peak in activity that is characteristic of being awake. Scientists have suggested that it is associated with depolarization of neurons due to hypoxia - a lack of oxygen. It has also been suggested that people who have gone through near-death experiences could have received their mystical experience at this very moment.

However, the effects of NDE are not only experienced on the eve of death. Similar conditions can be experienced without a threat to life.

When can you experience the effects of a near-death experience?

Recent research has shown that NDEs can be experienced with psychedelic drugs.

The experiment was divided into two parts: in one, the participants took the psychedelic dimethyltryptamine (DMT), and in the other, a placebo. After completing the trip, the subjects completed the NDE Scale questionnaires, compiled with the help of people who had had a near-death experience.

It turned out that after taking DMT, study participants experienced the same effects as people on the verge of death: a feeling of dissolution, a mystical experience of unity with the environment and those who fill it.

According to another study, only 51.7% of patients experience NDE on the brink of death. Of the 58 participants with near-death experiences, only 28 could actually die without the intervention of doctors. The remaining 30 people did not have a serious threat to life, but still survived all the effects of the near-death experience.

What Causes NDE Effects

Realizing your own death

One of the most common experiences is the realization of your own death. However, this feeling was also experienced by living people with Cotard syndrome (walking corpse syndrome).

A striking example is the case of a 24-year-old patient in a London hospital. She believed she died of a cold and was in heaven. After a few days, the mania began to subside, and then disappeared altogether.

This syndrome is associated with dysfunction of the parietal lobe and prefrontal cortex. It occurs after head injuries, during the advanced stage of typhoid fever and multiple sclerosis.

Light at the end of the tunnel

This experience is also often referred to when describing the near-death experience. Living people experience similar sensations. During overload, the pilots' blood pressure is greatly reduced and hypotensive syncope can occur, which is accompanied by temporary depression of peripheral vision. For 5-8 seconds, the pilots observe the same dark tunnel as people during the NDE.

There is an assumption that the tunnel arises due to the impaired blood supply to the retina. This state is typical for extreme fear and hypoxia, which, in principle, is close to dying.

Out of body

There is a suggestion that the angular gyrus is responsible for this experience. In one experiment, stimulation of this zone was found to induce a sense of transformation in the arms and legs of the subjects (response of the somatosensory cortex) and movement of the whole body (response of the vestibular system).

Scientists have concluded that out-of-body experiences can occur due to distortion of information from the somatosensory cortex and vestibular system.

Also, the experiences of out-of-body experience are characteristic of the state on the border of sleep and wakefulness - hypnagogia and sleep paralysis. In this state, a person can see hallucinations, be conscious, unable to move, and also experience the sensation of floating next to his body.

Happiness and well-being

The near-death experience is usually accompanied by a state of euphoria and calmness. The same effect can be obtained from taking certain medications, such as ketamine. This drug binds to the opioid mu receptors and causes euphoria, dissociation, spiritual experiences and hallucinations.

Scientists hypothesize that during NDE, the opioid reward system is activated to muffle pain, and the released endorphins create all the positive experiences.

There is also a theory that the euphoria is due to norepinephrine and blue spot - the brain region responsible for the release of this hormone.

Norepinephrine is involved in arousal of a person from fear, stress and hypercapnia - excessive amounts of CO₂in the blood, therefore it may well be excreted in a near-death state.

Blue spot is associated with the structures of the brain responsible for emotions (amygdala) and memory (hippocampus), response to fear and opioid pain relief (periaqueductal gray matter), dopamine reward system (ventral tegmental area). Scientists believe that the norepinephrine system may be associated with positive emotions, hallucinations, and other effects of near-death experiences.

All life before my eyes

In a near-death state, people often see a series of events in their own lives. In his book, Dick Swaab argues that people relive past events by activating the medial temporal lobe. This structure is involved in the storage of episodic autobiographical memories and is very sensitive to lack of oxygen, so it is easy to activate.

The study confirmed that in people who have experienced near-death conditions, the activity in the temporal lobe changes.

Meeting the dead

Many scientists believe that the near-death experience of a person takes place in an intermediate state between sleep and wakefulness, and the REM sleep phase is responsible for all mystical images and hallucinations.

To test this hypothesis, scientists studied 55 people who had experienced a near-death experience. It turned out that these people were more susceptible to sleep paralysis and the associated visual and auditory hallucinations. Scientists have suggested that in a state of danger, such people are more prone to immersion in REM sleep, and that is why they retained vivid memories of the near-death experience.

In addition, hallucinations are common in some brain damage. For example, patients with Alzheimer's or progressive Parkinson's sometimes report ghosts or monsters, and after brain surgery, some patients see dead relatives.

Is there life after death

Despite all the research and scientific theories, scientists lack the evidence to claim that NDEs are solely due to brain activity. On the other hand, people who prove the existence of the soul and life after death have no scientific evidence at all.

What to believe: life after death, your religion, unity with the Universe or the activity of a dying brain - it's up to you.