TEDxLaDéfense - Philippe VAN DEN BOSCH - Neurosciences et harmonie
Translator: Robert Tucker Reviewer: Ariana Bleau Lugo I'm going to talk to you about the brain and some facts about the function of the brain as human beings and in what is our humanism, in what is humanity that we possess inasmuch as we are humans and then see what we can do for the framework of the economy and profit-making. So, the brain is something that is, of course, very important to us. It is what allows us to perceive our environment, it is what allows us to act within our environment, so here you have a quite schematic representation of the brain. You realize that the brain occupies the cranial cavity. It is approximately 1.3 litres in size in women and it is 1.4 litres in size in men. Don't worry, ladies, this is an average which relates simply to body weight, it just proves that men are on average larger. And therefore, proportions are the same. What will make you happy, I expect, is that the biggest brain known in the world is that of a Frenchman. It is the brain of Louis Poincaré, the mathematician, which is preserved at the Salpêtrière hospital. That's the brain which is recognized as the largest. The brain, brain size and the weight of the brain do not in fact relate to intelligence as such. There are other factors involved and it is primarily about that that we will talk. This representation here of the brain is a general map of the brain. You see for example, the visual cortex is located at the back of the brain, here. You should know that you see me upside down. Your visual cortex, in fact, sees me upside down and it is after that you reconstitute the correct image. Me, I also see you upside down. Rest assured, I also see you properly. So, and then you have the so-called somatosensory area, this deals with sensations coming from the body the motor cortex, the language cortex, the cortex of emotions, which is the hippocampus, etc. All these parts of the brain are areas which are assigned to different functions: If we remove the visual cortex, in principle, vision is profoundly altered, if we remove the cortex dealing with language articulation predictably speech is disturbed, which are the findings of research and observations by Broca. What is important is that all of these brain areas work together all the time. It is a fine example of cooperation and association which is unfortunately not observed everywhere but the brain itself is very cooperative. And the cortex, and the whole of the brain, is made up of nerve cells called neurons. We have about 100 billion of them. 100 milliard neurons, each neuron connecting to about 10,000 other nerve cells, so you can imagine the number of connections. It is said that it nearly exceeds the number of connections that is to be found in the computers of the Western world. So a human brain is, if you like, on paper, more powerful than anything electronic. And this association that is absolutely extraordinary allows us to connect different areas and, needless to say, allows us to make up for deficiencies in whichever areas. We replace neurons; we have a neuronal population which is in permanent renewal in the sense that when one neuron becomes a little deficient, it is replaced by a neighbouring neuron. Well, I'm going to scare you; on average we lose around 10,000 neurons a day. With the reserve we have, this is not very serious, considering we live roughly a hundred years. The number of neurons lost is ten times larger, that is one loses 100,000 neurons a day where there is assault by alcohol for example; it is a big problem. We acquire our neuronal capacity at birth, and gradually, we develop our neural network which is genetically established from the beginning, a bit like the highways in a territory, and then we create, through our contacts with the environment, by our actions, a secondary network of neurons. And that's what makes the richness of character of each individual. This is what makes us all different, since we each have different experiences and it's what allows us to resist to different extents to different changes, these are subjects we have been working on in the laboratory for decades, to show in fact that the so-called epigenetic factor, which is outside us, shapes the neural cartography differently depending on the individual, and also shows that one is capable of resisting some changes. One of the big issues to work on is to be able to resist changes which are due to ageing which is a progressive loss of neurons over time. Anyway, these neurons allow by their connections the performance of a certain number of acts. So here you have a quite pragmatic example which is a glass of wine, and the neuronal development of the brain of each of us, we each have developed differently, will produce reactions of different characteral nature in relation to this glass of wine. The person who doesn't know wine well will say: "Yeah, it's a good red wine, I'll drink a drop." and then the person who is an oenologist or seasoned winemaker will -- not simply slop the wine about, but swirl it gently so it breathes, breathe in the aroma, taste it, let it rest, taste it again, etc -- will give its locality and vintage. The action is different according to the past of the person. And so we act, and Didier spoke of decision making, our actions, our decision, our programming as human beings depends on our past, the development, the sculpture, of our brain. So how is this brain sculpture established? It is established during childhood. First thing: when we are born, we are human beings, we must realize that we are born too early. We have a deficit of gestation of about 2 months. If we were apes, gestation for humans would last about 11 months. Then why are we born too early? Because the head grows in a more significant way than in primates and so to be able to pass the rigid pelvis that is somehow narrower because of the upright posture of man, this small pelvis must allow the passage of the newborn at a time when it can still pass, otherwise it creates problems obviously. And therefore the human child is born too early. It is released too early. And it is released completely helpless. Well, this has two consequences: Firstly, there is obviously a problem, which is that the human child is premature and all human children are premature, we are all premature infants, that have more or less managed with the fact that the brain is not yet mature, it is confronted with the environment sooner and therefore the external stimulation allows the brain to be wired in more powerful ways. This explains to a large part the cerebral and intellectual performance of the human compared to the great apes. Even though genetically, our genes differ from apes by only about 1.2 percent. Our genetic identity is not much different from that of a chimpanzee. The second thing is that the human child is born completely helpless. It is devoid of any capacity, and is therefore supported by its parents, It is supported by the group. It is supported by its parents and by the group. Being supported by the group is the beginning of socialization; it's the beginning of the social group. Then the human child is supported by its mother, possibly by its father who, it is said, is generally less present, It's generally mum who steps in. And there is what is called babbling, the mother and father introducing the child to the human world. The second thing is that there inside the brain, what is shown here, the so-called mirror neurons, neurons that allow us to communicate with each other but in a neuronal way: If I raise my right arm, neurons that would lift your right arm fire. The same thing when you see someone make a gesture, you can make the same gesture, but in an absolutely virtual way. These mirror neurons are also used to create what is called empathy, you look at your neighbour on your right, your neighbour on your left, you have empathy with one or the other, I will not ask you to tell me, it may not be so friendly! And these mirror neurons will create the social links, so the third stage, which is obviously all that is culture, learning, the integration of the human who establishes himself as a human then as an individual and as an individual different from others while in need of others. And then he will learn things, within the culture, this is the entrance into humanity. So all these things which combine are managed by the cortex called the pre-frontal cortex, which is right here, behind the forehead, and is increasingly important as evolution proceeds and which is the most important in humans. It is this cortex that allows us to decide and to act and perform according to our heritage, our neuronal history, to choose each time we act between the same types of event that we hold in memory; we adapt our brain history to the context and we realize what we need to do, we take a decision, perform an action, according to our set-up. Intervening here are emotions and pleasure. And so each individual is structured by his history. What is important here is that this pre-frontal cortex responds at different sites that are well located and if some of these sites are destroyed, there's a problem either in the decision making or in the resolution, which is seen most noticeably in those showing dementia: where in the taking of a decision, there's an inhibition of action, which is rather obvious. What is important is that all these circuits are associated with feelings of pleasure, with a substance called dopamine, which one comes across with people who take drugs. They take drugs because it increases their dopamine and that is what increases the effect of pleasure in the brain. The fact is that making decisions produces pleasure and the person has a tendency to take decisions which produce the most dopamine, that is to say the most pleasure. So, the problem that arises with decision-making and with profits, is that among a certain number of decision makers and a certain number of people, is that the increase in pleasure is such that it overpowers the emotions and that action is based on a value that has no correspondence with reality, it means that the person detaches himself completely from reality and somehow goes into a form of abstraction; this is what might be called a perversion of the act of decision. It has been shown very clearly in experiments in medical imaging where the people are extremely susceptible to gain, with these blue spots shown in the pre-frontal cortex, these are people where one can measure the amount of pleasure because experience shows that as they accumulate gains, so their pleasure increases and increases. And I would say to you on passing the amount of pleasure following the gain is greater than the amount of pleasure that is generated by looking, for example, at erotic images. This experiment has been conducted solely with men, which is shown in red. And therefore one could -- and this is obviously a caricature -- say that human evolution currently abandons humanism, the support of humanity which is in our brains, which is passed to us, to lead to activation of pleasure simply by the gain based on values which no longer have any relation to reality, which is a form of perversion. And as the erotic zones gradually fade, one may say, it's there where hope lies: those people do not reproduce. And so we have a bright future in front of us! Thank you. (Applause)