Lectures on the brain, part 1. The evolution of the human brain. Brain functions at every stage of its development


    I greet the entire Habr community. My name is Alexander Morozov. I am a practicing doctor, worked as a therapist, currently specializing in radiation diagnostics (working on CT and MRI), and work part-time in ultrasound diagnostics.

    I have a blog Collector of the Future, in which through various activities I talk about various progressive bioengineering, medical and other breakthrough technologies. I will gradually introduce you to my projects.

    In a series of video lectures, I will talk about the human brain from its evolutionary development to the opportunities that promise to give us neurocomputer interfaces in the next decade, from the macrostructure of parts of the cortex to the microstructure of neurons and signal transmitting neurotransmitters.

    Without knowing the history of the evolutionary development of the brain, it will be difficult to understand the intentions of researchers who will improve the functioning of the main organ of our nervous system. Therefore, meet the first lecture: “Evolution of the brain”!


    Welcome all. I am Alexander and I explain complex but interesting things in simple words.

    And now we are just about to discuss the most unusual and complex object that mankind knows. Let's talk about the brain. What is it, how does it work, how can it be improved and “repaired” already. And, most interesting, what methods of improving our brain are offered by well-known companies, researchers, geniuses, billionaires, playboys, philanthropists.

    To understand how our brain works now, you need to look a little back. Years on 600 million.

    The coolest thing you could see then was the sponge. Aquatic multicellular animals. No nerves. Without nerves, you can’t move or think, process all kinds of information. They simply existed and were waiting for death.

    But then some 20 million years passed and they appeared ... jellyfish! The first nervous system appeared - just a network of nerves. Now, when the jellyfish hits a stone, the whole body will know about it. The jellyfish’s nervous network allowed them to collect important information about the world around them - where are the objects, where are the predators, where is the food - and as if through a large social network, information came into all parts of the body. There is already a quality life, and not aimless rashing.

    After another 30 million years, steeper creatures appeared. Flatworms. The flatworm found that much more could have been done if someone in the nervous system was responsible for everything. A sort of godfather of the nervous system appeared. It is located in the head of a flat worm and runs the whole nervous system of the body so that it transfers new information directly to it. Therefore, instead of organizing itself into a network form, the nervous system of a flatworm crowded into a central channel of nerves that sent information back and forth between the boss and everything else. The head nerve nodes of the flatworm also run the rest.

    Other organisms quickly picked up the idea of ​​a boss in the nervous system, and soon thousands of species with brains appeared on Earth.

    Time passed, and the animals received complex and new bodies, so the brains became more and more busy. And 265 million years ago there were already creatures on whose nervous system our brain is based. Moreover, their nervous system often controls our actions (but more on that later). Frogs. Or rather amphibians. Their brain was already capable of a sort of automatic analysis of actions.

    The brain perfectly coordinated the impulses coming from the senses with the actions that need to be taken. He was fully responsible for the complex functions necessary for a living organism - respiration, heartbeat, digestion, excretion, and so on.

    A little later, mammals arrived. For the animal kingdom, life was already complicated. Yes, their hearts had to beat, and their lungs breathed, but mammals wanted more than just to survive - they acquired complex feelings, such as love, anger and fear.

    Therefore, the second boss appeared in mammals, who began to work in tandem with the reptile brain and took care of all these new needs. So 225 million years ago, the world's first limbic system, responsible for the senses, appeared.

    Over the next 100 million years, the life of mammals became more complex and eventful, and one fine day, 80 million years ago, an early version of the neocortex (a new section of the brain that we know as the cortex) appeared. With the advent of primates, and then large apes and the first hominids, strategic thinking begins to emerge.

    The ideas of the new department turned out to be very useful, tools appeared, hunting strategies and cooperation with other hominids.

    Over the next several million years, the neocortex grew older and wiser, and his ideas constantly improved. He understood how to get rid of nudity. He understood how to control the fire. He learned to make spears.

    But his coolest trick was thinking. He turned the head of each person into a small world-in-himself, making people the first animals that can comprehend complex thoughts, reason and come to decisions, build long-term plans.

    And then, somewhere 100,000 years ago, a breakthrough occurred. People started talking. The human brain developed to the point where it began to realize that a set of sounds, such as a “stick”, was not a stick in itself , but it could be used as a stick symbol - a stick was meant by this sound.

    Very soon words appeared for all kinds of things, and by 50,000 BC people were already communicating in a full, complex language.

    Neocortex turned people into magicians. Not only did he make the human head a wonderful inner ocean of complex thoughts, his latest breakthrough found a way to translate these thoughts into sounds and send them to vibrate through the air into the heads of other people who could decipher these sounds and absorb the ideas invested in them into their own ocean of thoughts . The man’s neocortex pondered things for a long time - and now, finally, he had someone to discuss them with.

    We can say that a neocortex party has gathered. The neocortexes began to share with each other everything they could: stories from the past, formed opinions, plans for the future.

    But the most useful thing was to share with his fellow tribesmen everything that he himself had learned. If one person understood by trial and error that berries of a certain type make life 48 hours a nightmare, he could already speak with his tongue about his difficult lesson in the rest of his tribe. Tribal members can use the language to pass this lesson to their children, and their children to their children. Instead of different people repeating the same mistake from time to time, one of them may say “do not eat these berries,” and from then on his wisdom will pierce space and time, protecting everyone from unpleasant moments.

    The same thing happens when one person comes up with some new tricky trick. For example, one unusually clever hunter who likes to observe annual patterns of migrating herds of wild animals can share his developed system. Disseminating knowledge will make the hunting season more effective and give tribe members more time to work on their weapons, which will allow one brilliant hunter in several generations Find a way to create lighter and stronger copies that you can throw more accurately.

    Language allows the best insights of the most intelligent people to be transmitted through generations, accumulating in a small collection of tribal knowledge, consisting of the best ideas of their ancestors. Now each new generation will receive this knowledge as a starting point for life, and it will lead them to even more abrupt discoveries based on the knowledge of their ancestors. The wisdom of the tribe will grow and expand.

    Each generation can learn much more when everyone is talking to each other, comparing notes and combining their individual knowledge. And each generation can successfully transfer a high percentage of its knowledge to the next generation, therefore, knowledge is better preserved over time.

    Shared knowledge becomes like a great, collective collaboration between generations. Thanks to the language, a spear innovation will go through hundreds of changes over tens of thousands of years and become a bow and arrow.

    Language gives a group of people a collective mind that far exceeds individual human intelligence and allows each person to benefit from the collective mind, as if he himself invented it all.

    You might think that we deviated from the topic of the brain, but we will need these aspects of the formation and functions of the language to understand the intentions of researchers who want to pump our brain.

    5-6 thousand years ago, another giant breakthrough occurred - a letter. And if language allows people to send thoughts from one brain to another, writing allows them to put thoughts on physical objects. Further, the printing press made knowledge more accessible. We will not focus on the fact that Gutenberg did not invent such a machine, but simply slightly modified the invention of the Chinese, made a couple of centuries before it.

    But still, it was a breakthrough! Now you don’t have to manually rewrite books! Although this work of rendering metal letters on a tile, smearing them with ink and pressing it on a sheet of paper with an output capacity of 25 pages per hour now seems ahem ... sucks.

    Anyway. Over the next centuries, printing technology improved rapidly, and the number of pages that a machine could print in an hour by the beginning of the 19th century was already 2,400. Not bad.

    However, this does not compare with our time. Although, in truth, paper generally goes out of fashion. Further more. The thoughts of one person could already reach millions of people. The era of mass communication has begun. And in the XX-XXI century, scientific discoveries pour in, as if from a cornucopia. So here. All this allowed all miracles of technology that we know to appear. Nowadays, people invent things that would seem absurd science fiction to people the year before last. But enough of the story, it's time to move on to something truly interesting!

    Next, we are waiting for knowledge about the structure and functioning of the brain, about the methods of studying it, about the existing neurocomputer interfaces, and about the future possibilities of the technical development of our brain. Special

    thanks to arielf for help with this article .

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