What do people think before they die

  One thing that interests almost everyone but is difficult to study is near-death experiences. A popular saying is that before death, a person will see a white light, leading him to another world. There are also many people who believe that when people die, they will experience a process of out-of-body experience, which is like looking down on their physical body from the sky.
  Another equally popular plot was used in the Hollywood blockbuster “Doomsday”. Well-driller Harry, played by the famous movie star Bruce Willis, manually detonates a bomb, blowing up an asteroid that is about to hit the earth. Before he died, he quickly went through his life in his mind like a movie, because it is said that every person who is about to die will have such a life flashback.
  Which statement is more accurate? no one knows. Because according to the strict definition, only an experience that occurs in the moment before death can be called a near-death experience. It’s a pity that the dead can’t speak, and people can’t come back to life after death, so all the current claims about near-death experiences come from those who survived after struggling around the death line, and they can’t be regarded as real near-death experiences.
  The only way to solve this problem is to use some high-tech method to measure the brain of a living person until he dies, and then deduce from the measured signal the moment when he crossed the hurdle of death. Thinking about something.
  The two most commonly used techniques to measure the brain are electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI). The former measures the collective firing patterns of neurons in the brain, and the spatial resolution is too low. The latter measures the oxygen consumption of brain neurons, and the spatial resolution is greatly improved. A research team from the Massachusetts Institute of Technology (MIT) used fMRI technology to discover a group of neurons in the human brain that are responsible for listening to music in 2015, which was definitely a remarkable achievement back then.
  However, the researchers were not satisfied with this result. They also wanted to investigate whether different types of music corresponded to different neurons, but they had to use a technique called electrocorticography to do so. As the name suggests, this technology connects electrode sensors directly to the cerebral cortex, so that the patterns of neuronal activity measured are much more refined than fMRI. However, the measurer must first open the subject’s skull through surgery, which is too traumatic, and probably few people are willing to become volunteers for this kind of research.
  However, there is one group of people who often use this technology, and that is people with epilepsy. Doctors usually use electrocorticography to confirm the focus of epilepsy before surgery so that they can be cut as accurately as possible. This process usually takes several days. If patients are willing to undergo psychological tests during this period, it can help neuroscientists bypass ethical obstacles and obtain valuable experimental data.
  So, the MIT research team spent several years finding 15 epilepsy patients who were willing to cooperate, and conducted detailed hearing tests on them before the operation, and the results were astonishing. Scientists have discovered a group of neurons that barely respond to pure music played by instruments and very weakly to human speaking sounds, but respond strongly to singing sounds, indicating that they are specifically responsible for listening to others singing.
  The researchers wrote a paper on the experimental results and published them in the journal Current Biology. The author believes that this result shows that singing may have some kind of evolutionary advantage, so humans have evolved neurons specialized in listening to singing, which helps humans quickly distinguish singing sounds from noisy background sounds.
  If you were surprised by this result, another article in the journal Current Biology is even more incredible. The authors of this paper are from the Universities of Tübingen and Bonn in Germany. They used the same method as the MIT experiment to study the brains of epilepsy patients. They were surprised to find that there are not only neurons dedicated to arithmetic in the human brain, but even addition and addition. There are dedicated neurons for subtraction.
  In order to prevent experimental errors, the researchers deliberately tested two different ways of writing questions. One is to use mathematical symbols to ask questions, such as “3+5=?” ​​or “9-2=?”. The other is to use language to describe arithmetic problems, such as “what is two plus seven” or “what is eight minus three”, in order to prevent what the electrocorticogram measures is actually the subject’s response to special symbols. The results once again proved that these two groups of neurons corresponded not to a certain symbol, but to a specific algorithm.
  What’s more interesting is that the researchers input the neural signals into the computer, trained an artificial intelligence program, and then used the trained program to guess whether the subject was doing addition or subtraction, and the results were all correct. If the researchers of the above two experiments cooperate and use this algorithm to measure the brains of the subjects, they should be able to know whether they are doing arithmetic problems or listening to music at this time.
  If this algorithm continues to improve, can it be used to study human near-death experiences? Theoretically, it is possible, but the ethical barrier cannot pass. This kind of experiment is not in line with humanitarian principles, and it is almost impossible to do it.
  An unfortunate event happened not long ago that gave scientists such an opportunity by accident. An 87-year-old man was sent to the hospital because of an accidental fall. The doctor found that the old man had epilepsy and gave him anticonvulsant drugs. At the same time, he monitored the old man’s brain with an EEG measuring device to prevent accidents. Unexpectedly, the old man died of a sudden myocardial infarction during the treatment, and the hospital’s brain wave measuring instrument was always on, so the doctors accidentally obtained the EEG of the old man for 30 seconds before and after his death.
  A group of brain neuroscientists from all over the world analyzed this rare EEG and found that the brain waves continued for a period of time after the blood had stopped flowing, especially the alpha and gamma waves were extremely active. The cross-coupling phenomenon between them is also very obvious. According to previous experiments on healthy people, the cross-coupling of these two waveforms often means that the subjects are engaged in high-intensity thinking activities, and it is likely to be related to memory retrieval.
  The researchers publish the results of their analysis in a paper. The author pointed out that this result is very similar to the experiment conducted by American scientists on mice in 2013, and the brain wave characteristics of the two are almost exactly the same.
  However, the author also admits that this conclusion is only a guess, because the relationship between brain waves and thinking patterns is still very uncertain, coupled with the blood clots in the old man’s cranial cavity due to wrestling, and the anticonvulsant drugs he is taking And other factors, are likely to have an impact on brain waves.
  In any case, this result allows scientists to peek into the brain before death for the first time from the outside, so it is possible to speculate what people are thinking before death, and help humans face death more calmly. Imagine the relief we would feel if we knew that our loved ones were looking back on their wonderful lives before they died.