Dec 24, 2021 09:00:00

What are the 'three scientific myths about the brain' that many misunderstand?

In the 21st century, remarkable progress has been made in many scientific fields, such as the advent of self-driving cars, the progress of exploration of Mars, and the rapid development of vaccines against new infectious diseases, but there are still 'obsolete scientific myths'. And that.

There, Lisa Feldman , a professor of psychology at Northeastern University , is known for his books such as 'Dr. Barrett's Brain Science Class 7 1/2 Chapter ' about the 'three scientific myths about the brain' that many people have.・Mr. Barrett explains.

That Is Not How Your Brain Works --Issue 111: Spotlight --Nautilus
https://nautil.us/issue/111/spotlight/that-is-not-how-your-brain-works

◆ Myth 1: The human brain is made up of a combination of parts with specific functions
The brain is divided into parts such as 'parts in charge of vision', 'parts in charge of memory', and 'parts in charge of emotions' for each function, and there is an idea that the brain is made by combining these parts. This view first appeared in the 19th century, with the spread of phrenology, which allows us to infer personality and mental characteristics from the shape of the skull, and remained among the general public even after the decline of phrenology.

In modern science, it turns out that the brain is not a combination of parts with specific functions, but a large network of nerve cells (neurons). Most neurons have multiple functions rather than a single function. For example , the area called the anterior cingulate cortex is involved in memory, emotions, decision making, pain, moral judgment, imagination, attention, and empathy. He pointed out.

In addition, the part called the primary visual cortex is closely related to vision, but at the same time, it is also known to convey information on hearing, touch, and movement. In an experiment in which a visually impaired person was blindfolded for several days to teach Braille, it was also found that neurons in the visual cortex concentrate on the transmission of tactile information. Also, damage to the temporary visual cortex on one side of the brain does not mean that the corresponding eyes are immediately blind, Barrett said.

The most prominent examples of the myth that the brain is made up of parts are the 'human brain' that controls instinct, the 'mammalian brain' that controls emotions, and the logical and ethical thinking that is peculiar to humans.

It is the 'trinity brain theory ' that is divided into three layers of 'human brain'. It is the neocortex at the top that makes humans human, and the idea that it can control the brain that controls emotions and instincts inherited from ancient animals was that the tool for examining the brain was a microscope. He was born in the times.

However, recent molecular genetic studies have denied the Trinity brain theory, where the brain does not evolve as a layer, and all mammalian brains are made through the same type of neurons and a single manufacturing process. I know there is. Barrett points out that animal brains only have adaptations to their environment, and that the brains of certain species are not more evolved than others.

One of the reasons why the myth that 'the brain is made up of a combination of parts responsible for a specific function' is not obsolete is that research using brain scans is expensive, so in many studies 'only the strongest brain activity' A scan that can detect is used. ' Studies conducted in this way show that the brain is quiet in normal times, and although it is easy to have the illusion that a part of it is active only in certain situations, the whole brain is actually always active. That. Also, it seems that animal experiments may focus on only a few neurons, which is also one of the reasons why the network of the whole brain is hard to pay attention to.

Why was the 'trinity brain theory' that the human brain is divided into three layers long believed? --GIGAZINE

◆ Myth 2: The brain reacts to world events
One of the mistakes many people make is, 'The brain is basically off, and when it receives a stimulus in the face of some particular event, it turns on where it's needed and begins to work. There is an idea. This seems correct at first glance, but Barrett said, 'The brain doesn't work with stimuli and responses. All neurons are constantly firing at different speeds.' It points out that it is not.

What the constantly firing neurons are doing is 'prediction'. The brain constantly uses available information such as one's memory, one's situation, and one's physical condition to predict 'what will happen in the next moment', and if the prediction is correct, it will respond to the event. You can immediately move, see things, and hear sounds. If the prediction is wrong, he corrects himself and uses it for the next prediction.

Predicting the world from past experience and knowledge and continuing to modify yourself is a far more efficient way to live in a world of high uncertainty than to live solely on stimuli and reactions. For example, baseball players and table tennis players do not actually look at the ball and move the bat or racket, but move the bat or racket by predicting the position of the ball based on experience and hit the ball at the appropriate position. I am. Barrett says that if humans are animals that simply respond to stimuli and the brain does not have the ability to make predictions and corrections, people will not be able to play sports.

◆ Myth 3: Physical and mental illnesses are distinctly different
The third myth believed by people is that there is a clear line between physical illnesses such as cardiovascular disease and mental illnesses such as depression. Many people still distinguish between the body and the mind, but recent findings by neuroscientists are that the brain network that controls the body is deeply involved in the mind, and the two are not clearly separated. It shows that it is. For example, the anterior cingulate cortex of the brain plays a role in keeping the body healthy through organs, hormones, and the immune system, in addition to psychological functions such as memory, emotions, decision making, pain, moral judgment, imagination, attention, and empathy.

It is also known that physical changes in the body affect the mind, as it is said that

people with cardiovascular disease and brain disease are more likely to suffer from depression. Some researchers suspect that depression or cardiovascular disease may cause the other, and it has been pointed out that both may have a common cause.

'When considering the relationship between the mind and the body, it is fascinating to be satisfied with the myth that the mind is in the brain and is separate from the body. While you're adjusting, you're creating your mind, which means that body adjustment is itself a part of your mind, 'Ballett said.