But what happens to our brain when we die? It is a very difficult question to answer, and many of us imagine it as a transitory experience where we walk along a path surrounded by our loved ones. Or maybe, walking through a dark tunnel with a bright light at the end.
When death comes, the body undergoes a series of critical changes that we experience individually and uniquely, becoming a secret that only you will surely know. But whatever it is, scientists claim that those final moments of consciousness during the threshold of death may be driven by something incredible and mysterious taking place in our brain.
Clinical death is defined as the interruption of the bodily functions of any living being, the electrical impulse that makes the heart function is interrupted, and the heart stops. Any external signs of life, such as pulse, consciousness, and breathing, disappear.
A team of scientists has studied near-death experiences and what happens during that time when the body stops working. Trying to find answers, they managed to unveil something remarkable. A surge of electricity invades the brain just before brain death.
In 2013, a team of scientists from the University of Michigan made a discovery when clinical death occurred in rats, during the process their brain activity ceased, revealing traces of electrical activity in the brain that reached levels higher than those found in the waking state of the animals.
"We reasoned that if near-death experience stems from brain activity, neural correlates of consciousness should be identifiable in humans or animals even after the cessation of cerebral blood flow," Say Jimo Borjigin, one of the team
The rats were anesthetized and induced cardiac arrest, detecting this incredible highly synchronized neural activity within 30 seconds during clinical death, entering a hyper-alert state before brain death occurred.
This is a great revelation, as there is the notion that the brain stops functioning within 20-30 seconds of a cardiac arrest, as blood stops flowing to the brain, stopping almost immediately all brain function along with the organ functions governed by it.
"This study tells us that reduction of oxygen or both oxygen and glucose during cardiac arrest can stimulate brain activity that is characteristic of conscious processing," said Borjigin.
This establishes a new framework for determining the origin of near-death experiences, but not necessarily this entourage explosion may occur in humans, but it may help explain the state of consciousness that many people who have experienced after clinical death have experienced.
A more recent study conducted in 2014 at Stony Brook University, led by researcher Sam Parnia, which published results that derived from the study 100 people who had survived cardiac arrest and experienced their own experiences of a type of consciousness during the veil of death.
More than 40% of those interviewed said they remembered a series of events during these moments, such as bright lights, dead relatives and fear. But even more intriguing were the statements of two patients who were able to recall events related to the resuscitation procedure, conversations between doctors, nursing staff, resuscitation techniques, right after their death.
This is something that should not have been possible from the more conventional point of view of knowledge about consciousness beyond clinical death.
"We know the brain can't function when the heart has stopped beating, but in this case conscious awareness appears to have continued for up to three minutes into the period when the heart wasn't beating, even though the brain typically shuts down within 20 to 30 seconds after the heart has stopped.". Say Parnia said in the report.
Dr. Parnia in some statements states that the scientific community has not taken these near-death claims and extracorporeal experiences seriously and sees the need for more unbiased research to document and expand the scientific literature on this topic.
These experiences may also arise from a neurological response to physiological stress during underlying cardiac events during clinical death. That is, a cognitive experience that precedes clinical death itself and manifests itself in the patient's memories.
Although these experiences are not consistent with what was demonstrated in the rat experiment, scientists are still finding evidence of amazing biological processes that occur when death knocks on our door.
There are no clear answers yet, but science has given us a fascinating insight into what the final moments of our lives might be, which we definitely don't know how it looks or feels, but we all will someday.