What Happens To The Brain At The Time Of Death
Why do people leave the body, fall into a dark tunnel and see dead relatives?
People who have been on the verge of life and death always tell about the same thing: a person glides along a dark tunnel to the bright light at the end, he is surrounded by a feeling of absolute peace and happiness, 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 side and experience a feeling of soaring.
Having received near-death experience (near-death experience, NDE) sincerely believe in the reality of their experiences and use them as evidence of the existence of the soul and life after death. However, neurophysiologists suggest that all the effects of NDE are due to the functioning of the dying brain.
What happens to the brain after cardiac arrest
Using electrodes implanted in the patients' brains, neurologists discovered Terminal spreading depolarization and electrical silence in death of the human cerebral cortex that even after the cessation of the heartbeat, the nerve cells of the brain continue to function.
Death is marked by the last wave of brain electrical activity. This wave begins 2–5 minutes after the oxygen-saturated blood stops entering the brain and displays dangerous neural changes that lead to irreversible damage.
A short burst of activity was also found in an earlier study, Surges of electroencephalogram activity at the time of death: a case series. Scientists performed electroencephalography (EEG) in dying people and found that after the loss of blood pressure there follows a temporary peak of activity, which is typical for a stay in the mind. Scientists have suggested that it is associated with depolarization of neurons due to hypoxia - a lack of oxygen. They also suggested that people who went through near-death experiences could get their mystical experience at that very moment.
However, the effects of NDE are experienced not only in anticipation of death. Similar conditions can be felt without a threat to life.
When can I experience the effects of a near-death experience?
A recent study showed the DMT Models the Near-Death Experience that near-death experiences can be experienced with psychedelics.
The experiment was divided into two parts: in one, participants took psychedelic dimethyltryptamine (DMT), and in the other, placebo. Upon completion of the trip, subjects completed the NDE Scale questionnaires compiled by people who had experienced near-death experiences.
It turned out that after taking DMT, the study participants experienced the same effects as people on the verge of death: a sense of dissolution, a mystical experience of unity with the environment and those who fill it.
According to another study, Features of "near-death experience" in relation to whether or not patients were near death., Only 51.7% of patients experience NDE on the verge of death. Of the 58 participants with a near-death experience, only 28 could truly 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 the effects of the near-death experience
Awareness of own death
One of the most common experiences is awareness of one's own death. However, this feeling was also experienced by living people with Kotar syndrome (walking corpse syndrome).
A striking example is a case Attributional style in the case of Cotard delusion. A 24-year-old patient at a London hospital. She believed that she died of a cold and is in heaven. A few days later, the mania began to subside, and then completely disappeared.
This syndrome is associated with impaired function of the parietal lobe and the prefrontal cortex. It is observed after head injuries, during the advanced stage of typhoid and multiple sclerosis.
Light at the end of the tunnel
This experience is also often mentioned in the description of the near-death experience. Living people experience similar sensations. During the pilot's overload, blood pressure decreases significantly and hypotensive fainting can occur, which is accompanied by temporary depression. Direct determination of man’s blood pressure on the human centrifuge during positive acceleration. peripheral vision. For 5–8 seconds, pilots observe the same dark tunnel as people during NDE.
There is speculation that the tunnel arises Out-of-body experience and arousal. due to impaired blood supply to the retina. This condition is characteristic of extreme fear and hypoxia, which, in principle, is close to dying.
Out of the body
There is an assumption that the angular gyrus is responsible for this experience. In one experiment, Stimulating illusory own-body perceptions. found that stimulation of this zone causes a sensation of the transformation of the arms and legs of the subjects (response of the somatosensory cortex) and movement of the whole body (response of the vestibular system).
Scientists concluded that an out-of-body experience may occur due to the distortion of information from the somatosensory cortex and the vestibular system.
Out-of-body experiences are also characteristic of a state at the border of sleep and wakefulness - hypnagogia and sleep paralysis. The body unbound: vestibular-motor hallucinations and out-of-body experiences... In this state, a person can see hallucinations, be awake, unable to move, as well as a feeling of soaring next to your body.
Happiness and prosperity
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 opioid mu receptors and causes a state of euphoria, dissociation, spiritual experiences and hallucinations.
Scientists suggest that during the NDE, an opioid reward system is activated to mitigate pain, and the released endorphins create all the positive impressions.
There is also a theory that euphoria is worth giving thanks to norepinephrine. There is nothing paranormal about near-death experiences: how neuroscience can explain seeing bright lights, meeting the dead, or being convinced you are one of them. and the blue spot is the part of the brain responsible for the release of this hormone.
Norepinephrine is involved in arousal of a person from fear, stress and hypercapnia - an excessive amount of CO2 in the blood, so it may well be released in a near-death state.
A blue spot is associated with brain structures responsible for emotions (tonsil) and memory (hippocampus), response to fear and opioid analgesia (near-water gray matter), dopamine reward system (ventral region of the tire). Scientists believe that the noradrenaline system can be associated with positive emotions, hallucinations and other effects of the near-death experience.
A whole life before my eyes
In the near-death state, people often see a series of events in their own lives. In his book “We are our brain. From the uterus to Alzheimer's, ”Dick Swaab argues that people experience past events through activation of the medial temporal lobe. This structure is involved in storing episodic autobiographical memories and is very sensitive to a lack of oxygen, so it is easy to activate.
A study by Near-Death Experiences and the Temporal Lobe 2004, Britton confirmed that people who have experienced a near-death condition have an activity in the temporal lobe.
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 BDG phase of sleep is responsible for all mystical images and hallucinations.
To test this hypothesis, scientists examined the Does the arousal system contributes to near-death experience? 55 survivors of the near-death experience. It turned out that these people were more susceptible to sleep paralysis and related visual and auditory hallucinations. Scientists have suggested that in a state of danger, such people are more prone to immersion in BDG-sleep, and that is why they have preserved vivid memories of the near-death experience.
In addition, hallucinations are characteristic of some brain injuries. For example, patients with Alzheimer's disease or progressive Parkinson's disease sometimes talk about ghosts or monsters, and after surgery on the brain, some patients see dead relatives.
Is there life after death
Despite all the research and scientific theories, scientists lack evidence to claim that the near-death experience is due solely 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 - you decide.