Although it is really inhuman to discuss these things in front of the dead, the people who eat melons also want to know. Can the dead really hear during the discussion?
What is the process of human death? You can still hear it after death?
There are two kinds of human death, one is brain death. This understanding is simple. Just like the CPU of a computer is burned, even if the peripheral hardware is intact, it will die, but the CPU of the computer can be replaced, and the human brain has nothing to change, and it is no longer self!
The other is that the peripheral key organs are broken. For example, if the motherboard south bridge north bridge, or the power supply, or the power supply chip is broken, the computer will hang up. In this case, it is generally enough to replace the accessories, so many people can survive for many years after organ transplantation. Of course, after the spread of cancer, the whole body is full of cancer cells, and there is no chance to change the "site", so it is completely hopeless.
We discuss the latter, because patients with direct physical and brain death probably don't need to discuss it, just like if you directly drill a hole in the CPU of a computer with an electric drill, you can't even shout!
After death, which organ strikes at the latest?
The answer is really listening!
The first thing that disappears is vision, which seems easy to understand, because it may even lose the power to lift the eyelids, and the brain needs to consume a lot of energy to deal with stereoscopic vision, so it is better to close your eyes when there is no power.
Then the sense of touch disappears, but the human body will eventually supply energy to the brain, the body surface will lose blood and lose temperature, and the sensory nerves will have no blood supply and no numbness.
The last thing that disappears is hearing. The reason is very simple, because hearing is closest to the brain, and auditory conduction converts sound signals into electrical signals through hair cells in cochlear fluid, and then transmits them to the brain. Its conduction nerve is very short and consumes little. Basically, as long as the brain is alive, there will be hearing.
Can people still hear after death?
Electrical signals from cochlear hair cells are inaudible until they are sent to the brain for processing. Otherwise, it is like a dynamic microphone. The electrical signal sent out after vibration has not been processed by the circuit, so this signal is meaningless.
So theoretically, the electrical signal from this cochlear hair cell after brain death is simply "unattended", so how can it be said that it is hearing?
Scientific reports overturn research and refresh our cognition.
On July 8, 2020, scholars from British Columbia University published an article entitled "Persistent Hearing at the End of Life" in the Science Report, which told a very interesting phenomenon about the brain's response to sound when the human body was on the verge of death. This discovery will help family and friends to give their loved ones their last care at the last moment.
The researchers used EFG (electroencephalogram) to measure brain activity and analyze the differences between healthy control group and dying patients, as well as the unresponsive process. The researchers found that a few hours before the official death, the patient entered an unresponsive period.
However, researchers have found that even dying patients respond to sound much more obviously than other ways of perception. In other words, even if the patient is unconscious, he can still hear the surrounding sounds before entering the formal brain death. So in theory, even if there is no response, relatives who come to visit can let the patient know through words to visit him.
Lawrence Ward, a professor of psychology at UBC, said that this discovery was confirmed by comparing the recognition degree of sounds between many patients and healthy people. Dr Gallagher, who has 30 years' experience in hospice care, also said that she witnessed the very positive side of hospice care for patients, so she agreed with this discovery.
However, according to the researchers, although the research shows that there is a response, it is impossible to measure whether the patient really understands and processes the information from a practical point of view, because the patient who enters the death procedure cannot tell the researchers.
Research on Langone School of Medicine, new york University, USA
Sam parnia, the director of the intensive care and resuscitation research program at Langone Medical College of new york University, is even more amazing. They found that the time interval between the heart stopping beating and the brain stopping blood supply and the brain stopping brain waves was somewhat beyond their expectations.
In 20 13 years, researchers from the University of Michigan in the United States induced heart disease in nine anesthetized experimental rats, and then observed the brain wave activity after the clinical death of the rats. Results "emergency" brain waves were observed. Simply put, the heart stops beating, and after the brain stops supplying oxygen, the human body will burst into an emergency state of excitement, which is enough for the brain to handle many physiological activities!
Fig. 1 structural diagram of rat brain (left) and human brain (right).
However, the relevant researchers did not say how long this time was, but what we can learn is that these activities can be diagnosed by brain waves, and the modern standard for judging brain death is much stricter than this. So theoretically, when the heartbeat stops, you can hear the sound completely, but it is impossible after brain death.
Therefore, people who eat melons can chat at ease, but the problem is that there is still an ethical problem, and it is inappropriate for us to do so because of emotion and reason. After all, the dead are the most important.