Myths about the work of the human brain

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

Neuromyths, that is, misconceptions about the capabilities of our brain, are often based on misinterpreted or too old results of scientific research. The team of neuroscientists at the National Center for Scientific Research and the University of Orleans proposes to dispel several neuromyphs using play-in-the-material on the Slate website.

On the occasion of Science Celebration October 6-14, a team of neuroscientists at the National Center for Scientific Research and the University of Orleans is offering to use play to dispel several neuromyphs.

Its conditions look like this: panic in the neurobiological laboratory! Professor Sibulo found that neuromiphs quickly spread among the population and disrupt the brain of everyone who caught them. Therefore, it is necessary, without wasting time, to rectify the situation before they cause irreparable damage.

Professor Sibulo needs your help. You take on the role of a neuroscientist, and your task is to find the various neuromyths and destroy them.

Myth # 1: Brain Size Affects Intelligence

"Your head is empty!" "You've got bird brains!" Such expressions are often used to indicate to a person his stupidity and absent-mindedness. They are rooted in long-standing views of the relationship between brain volume and intelligence.

The elephant's brain weighs 5 kg, and the brain of the sperm whale weighs 7 kg, that is, almost 5 times more than ours (on average, 1.3 kg). And even if we start from the ratio of brain weight to body weight, we will still lose: this time - a sparrow, whose brain accounts for 7% of the mass versus 2.5% for us.

Now let's compare the brain weight of modern humans and their ancestors. In 7.5 million years, the size of the brain has tripled. Be that as it may, in our species "homo sapiens" its volume is constantly decreasing: by 15-20% compared to the Cro-Magnons.

Are there any differences between men and women? When it comes to brain size, several studies indicate that men have an average of 13% more brain size than women. Yes, but it's worth remembering that the brain of the famous physicist Albert Einstein was 10% less than normal.

So, do you think your intelligence is dependent on brain size?

Myth # 2: Decline after 20 years

According to the established dogma, after 20 years, the loss of neurons begins and, as a result, the beginning of the decline of our mental abilities.

Only this statement ignores the fact that we have already lost a lot of neurons much earlier, from birth. During the development of the embryo, an excess number of neurons is formed, more than half of which die off naturally. The elimination of extra neurons for the most part ends with birth. The loss of neurons during development is an important stage in brain maturation.

For decades, neuroscientists believed that we were born with a fixed number of neurons, and that any loss was irreparable. However, in 1998, a revolutionary discovery was made: the human brain produces neurons.

Subsequently, studies have confirmed that in one part of the brain, the production of neurons never stops: the hippocampus forms about 700 neurons per day in the brain of an adult.

Neurons are sensitive to the environment

The production of new neurons from stem cells is called neurogenesis. In both embryonic and adult stages of development, it is highly susceptible to the environment, in particular to the effects of pesticides.

A group of scientists from the Laboratory for Experimental and Molecular Immunology and Neurogenetics is studying the effects of pesticides on brain development, in particular on neurogenesis. Recently, experts have been able to establish that constant exposure to low doses in rodents leads to disturbances at the level of the brain regions that are responsible for the formation of new neurons.

Be that as it may, the environment can also have a positive effect on neurogenesis. In particular, it is facilitated by intellectual and physical activity, as well as social relationships. Be that as it may, the brain's ability to form new neurons does decrease with age.

In any case, the most important thing for the brain is not the number of neurons, but the connections between them. The loss of neurons is not so bad if effective connections are maintained between the rest.

Faster connections

But what determines the effectiveness of connections? Neurons connect at the synapse level. The more signals pass between two neurons, the stronger the synapse. Learning means making faster connections between neurons.

Frequently used neural pathways become expressways that facilitate problem solving and movement, and are also responsible for learning and forming new memories.

This process is associated with the plasticity of the brain, which, as has been clearly established, persists throughout our lives.

Among the mechanisms regulating this plasticity, it is worth noting the role of such chemicals present in the brain as neurotransmitters. They are free at the synapse level and provide communication between two neurons. Among them are glutamine, dopamine, acetylcholine and serotonin.

Serotonin is known to control psychological balance and is involved in regulating human mood. It is worth noting that some antidepressants affect the amount in the brain.

Be that as it may, serotonin also affects the memorization process. It acts on receptors on the surface of neurons to control their shape, the number of synapses and synaptic plasticity.

Employees of the Orleans Center for Molecular Biophysics have come to grips with the work of this neurotransmitter and its effect on receptors. In particular, they were able to establish that a disorder at the level of activity of one of the receptors can lead to learning disabilities within the framework of one genetic disease.

Neuronal plasticity and neurogenesis are complex mechanisms that persist throughout our lives, and are also the key to learning and adapting to new situations. So, do you still believe in the myth that the human brain begins to decline as early as 20 years old?