Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Темы на экзамен.docx
Скачиваний:
0
Добавлен:
27.09.2019
Размер:
51.47 Кб
Скачать

A brain on a supercomputer.

Computer realistic model of human brain was doing for some reasons. There are three important reasons:

  1.  It's essential for us to understand the human brain if we do want to get along in society, and I think that it is a key step in evolution. 

  2.  We cannot keep doing animal experimentation forever, and we have to embody all our data and all our knowledge into a working model. 

  3. There are two billion people on the planet that are affected by mental disorder, and the drugs that are used today are largely empirical. I think that we can come up with very concrete solutions on how to treat disorders.

Now, even at this stage, we can use the brain model to explore some fundamental questions about how the brain works.  So, this theory is that the brain creates, builds, a version of the universe, and projects this version of the universe, like a bubble, all around us.

 The reason why the moon is huge on the horizon is simply because our perceptual bubble does not stretch out 380,000 kilometers. It runs out of space. And so what we do is we compare the buildings within our perceptual bubble, and we make a decision. We make a decision it's that big, even though it's not that big.

And what that illustrates is that decisions are the key things that support our perceptual bubble. It keeps it alive. Without decisions you cannot see, you cannot think, you cannot feel. 

So, when you walk up to a door and you open it, what you compulsively have to do to perceive is to make decisions, thousands of decisions about the size of the room, the walls, the height, the objects in this room.  We can ask a very concrete question. "Can the brain build such a perception?" Is it capable of doing it? Does it have the substance to do it? 

So, it took the universe 11 billion years to build the brain. It had to improve it a little bit. It had to add to the frontal part, so that you would have instincts, because they had to cope on land. But the real big step was the neocortex. It's a new brain. You needed it. The mammals needed it because they had to cope with parenthood, social interactions,complex cognitive functions.

So, you can think of the neocortex actually as the ultimate solution today, of the universe as we know it. It's the pinnacle, it's the final product that the universe has produced. 

So you can think of the neocortex actually as a massive grand piano, a million-key grand piano. Each of these neocortical columns would produce a note. You stimulate it; it produces a symphony. But it's not just a symphony of perception. It's a symphony of your universe, your reality. 

In fact, there is a new theory of autism called the "intense world" theory, which suggests that the neocortical columns are super-columns. They are highly reactive, and they are super-plastic, and so the autists are probably capable of building and learning a symphony which is unthinkable for us. But you can also understand that if you have a disease within one of these columns, the note is going to be off. The perception, the symphony that you create is going to be corrupted, and you will have symptoms of disease.

There is the millons of branches that intersect actually in millions of locations, and at each of these intersections they can form a synapse. And a synapse is a chemical location where they communicate with each other. And these synapses together form the network or the circuit of the brain. Now, the circuit, you could also think of as the fabric of the brain. And when you think of the fabric of the brain, the structure, how is it built? What is the pattern of the carpet? You realize that this poses a fundamental challenge to any theory of the brain, and especially to a theory that says that there is some reality that emerges out of this carpet, out of this particular carpet with a particular pattern.

The reason is because the most important design secret of the brain is diversity. Every neuron is different. It's the same in the forest. Every pine tree is different. You may have many different types of trees, but every pine tree is different. And in the brain it's the same. 

So, how could we possibly create a reality that we can even understand each other? Well, we don't have to speculate. We can look at all 10 million synapses now. We can look at the fabric. And we can change neurons. We can use different neurons with different variations. We can position them in different places, orient them in different places. We can use less or more of them. And when we do that what we discovered is that the circuitry does change. But the pattern of how the circuitry is designed does not. So, the fabric of the brain, even though your brain may be smaller, bigger, it may have different types of neurons, different morphologies of neurons, we actually do share the same fabric. 

So, we have the mathematics to make neurons come alive. We also have the mathematics to describe how neurons collect information, and how they create a little lightning bolt to communicate with each other. And when they get to the synapse, what they do is they effectively, literally, shock the synapse. It's like electrical shock that releases the chemicals from these synapses.

And we've got the mathematics to describe this process. So we can describe the communication between the neurons. There literally are only a handful of equations that you need to simulate the activity of the neocortex. But what you do need is a very big computer. And in fact you need one laptop to do all the calculations just for one neuron. So you need 10,000 laptops. So where do you go? You go to IBM, and you get a supercomputer, because they know how to take 10,000 laptops and put it into the size of a refrigerator. So now we have this Blue Gene supercomputer. We can load up all the neurons, each one on to its processor, and fire it up, and see what happens. 

So, the way that we can look at that is to ignore the neurons, ignore the synapses, and look just at the raw electrical activity. Because that is what it's creating. It's creating electrical patterns. So when we did this, we indeed, for the first time, saw these ghost-like structures: electrical objects appearing within the neocortical column. And it's these electrical objects that are holding all the information about whatever stimulated it. And then when we zoomed into this, it's like a veritable universe.

So the next step is just to take these brain coordinates and to project them into perceptual space. And if you do that, you will be able to step inside the reality that is created by this machine, by this piece of the brain.