What happens beyond death has always been a metaphysical matter, more typical of other disciplines, such as religion or philosophy. On the other hand, from a scientific point of view, it seems quite clear that the electrical impulses that give rise to perceptions, thought, emotions, consciousness … are completely ‘turned off’ in the brain as soon as the body dies.
However, a team of scientists from NYU New York School of Medicine have come to different conclusions.
Dr. Sam Parnia, director of intensive care at this center, says that people “know immediately that they have died”, since their consciousness continues to function after the body has stopped emitting signs of life, according to a published study in 2017.
A conclusion reached by a team of researchers led by Parnia himself, after analyzing a group of patients who suffered cardiac arrest and who, technically, died, but were successfully resuscitated shortly after.
Among the conclusions of the study, it can be drawn that the patients were aware of the complete conversations and also of seeing the things that happened around them, even after having been declared deceased.
Medically, the time of death is defined as the time when the heart stops beating, and therefore the blood flow stops flowing to the brain.
However, according to Parnia’s team, there is evidence to suggest that an energy surge occurs in the brain when a person dies.
In fact, in 2013, researchers at the University of Michigan looked at the electrical signals inside the brains of nine anesthetized rats after being induced to have a heart attack.
Brief moments after clinical death, the researchers observed patterns of activity in the brain related to a state of ‘hyper alert’.
During a heart attack, a clogged artery prevents blood from reaching part of the heart, which can cause that section to die, even though the heart continues to beat. As a result, the electrical signals that control the pumping action of the heart are disrupted, the heart stops beating, and death occurs shortly thereafter.
The cerebral cortex, the ‘thinking part’ of the brain, is also instantly down, meaning no brain waves are produced, at least visible on a monitor, for around 20 seconds. This first reaction starts a chain of cellular processes that results in brain death. But, according to Dr. Parnia, “until this happens, it can take hours after the heart stops working.”
Performing cardiopulmonary resuscitation (CPR) sends some blood to the brain, “about 15 percent of what it requires to function normally,” according to Parnia. This is enough to slow the death of brain cells , but not enough to jump-start the brain to function again, which is why reflexes don’t resume during CPR, he said.
“If you can restart the heart, which is what CPR tries to do, little by little you will start to make the brain work again. The longer you are doing CPR, the neurons continue to die, only at a somewhat slower rate. “, Explain.
Referencias:
‘Awareness during resuscitation. A prospective study’. Sam Parnia. Resucitation Journal. DOI: http://dx.doi.org/10.1016/j.resuscitation.2014.09.004
