Neuralink Elon Musk. Part three: flight over a nest of neurons

Eccentric in the best sense of the word entrepreneur, playboy, philanthropist Elon Musk known around the world. He decided to bring humanity into space, to colonize Mars, to abandon a disposable rockets. He decided to make the world cleaner, transplanted us from cars with internal combustion engines to self-driving cars. While unfolding these businesses, he does not sit idly by. He conceived Neuralink that will help us become new people. Without borders and without weaknesses, as it should be in the new world (Elon musk). To document the crazy ideas Mask, as always, volunteered Tim urban from WaitButWhy (he wrote about artificial intelligence, colonization of Mars and SpaceX). We present one of the best works of modern popular science journalism. Further, in the first person.

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Flying over the nest of neurons

Let's for a moment go back in time to 50,000 BC, steal and somebody will bring it in 2017.

This Side. Side, thank you and your men for what you've invented a language.

To thank you, we want to show you all the incredible things we were able to build thanks to your invention.

Okay, let's put Boca on the plane, then a submarine, then pulled at the top of the Burj Khalifa. Now let's show him a telescope, TV and iPhone. And let a little sit on the Internet.

It Was fun. How do you Side?

Yes, we understand that you are very surprised. For dessert, let's show him how we communicate with each other.

The Side would be appalled if he knew that, despite all the magical abilities that people have acquired as a result of dialogues among themselves, thanks to the ability to speak, the process is no different from what was in his time. When two people are going to talk, they used technology of the age of 50 000 years.

The Side will also be surprised that in a world in which work amazing machines, the people who did these cars go around with the same biological bodies, which went Sideways and his friends. How is this possible?

That's why brain-computer interfaces (NCI) is a subset of the broader field of neural engineering, which itself is a subset of biotechnology, is so interesting. We have conquered the world with their technology, but when it comes to the brain is our main tool — the world of technology gives us nothing.

Therefore, we continue to communicate using technologies invented by Side. So I type this sentence 20 times slower than we think, and therefore, disease related to brain, still claim too many lives.

But after 50 000 years after the great discoveries the world can change. The next frontier brain he is.

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There are many different options for potential brain-computer interfaces (sometimes referred to as the interface "the brain — the computer" or "brain — the machine") that are useful for different things. But everyone who is working on CQM, trying to solve one, two or both of these questions:

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1. How am I going to extract the desired information from the brain?
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2. As I need to send information to the brain?

The First is the withdrawal of the brain — that is, record, say the neurons. The second relates to the introduction of the information in the natural flow of the brain or change the natural flow in some way — that is stimulating neurons.

These Two processes always occur in your head. Right now your eyes fulfil a set of horizontal movements that allow you to read this sentence. It is the neurons of the brain provide information to the machine (your eyes), and the car receives the command and responds. And when your eyes move a certain way, the photons from the screen to penetrate into your retina and stimulate the neurons in the occipital lobe of your cortex, allowing the picture of the world to get you in consciousness. Then this picture stimulates neurons in another part of your brain that allows you to process the information contained in the image, and to extract meaning from sentences.

Input and output — that make the brain's neurons. The whole industry NRI wants to join the process.

At First it seems that this is not such a difficult task. Because the brain is just a ball of jelly. And the cortex — the part of the brain that we want to add to our recording and stimulation — it's just a napkin, situated on the outer part of the brain, where it is easy to access. Inside the cortex has 20 billion neurons, 20 billion little transistors that can give us a completely new way to control our life, health and peace if we learn to work with them. Is it so hard to understand? The neurons are small, but we know how to split the atom. The diameter of the neuron in the 100 000 times more atoms. If the atom were a Lollipop, a neuron would be a kilometer in diameter — so we definitely should be able to work with such quantities. Right?

What is the problem?

On the one hand, it is correct idea because they lead to progress in the field. We really can do it. But once you start to understand what is actually happening in the brain, it becomes immediately obvious that this is the most difficult task for a person.

So before we talk about the CQM, we need to look at what people are doing are creating NKI. It is best to increase the brain 1000 times and see what happens.

Remember our comparison of the cerebral cortex with the napkin?

If we increase the tissue of the bark 1000 times — and she was about 48 inches on each side — now it will be the length of two blocks in Manhattan. It will take about 25 minutes to walk the perimeter. And the brain in General is the size of Madison Square garden.

Let's put it in the city. I'm sure several hundred thousand people who live there, we'll understand.

I chose a 1000-fold increase for several reasons. One of them is that we all can instantly convert dimensions in your head. Every millimeter the actual brain became a meter. In the world of neurons, which is much less each micron became a millimeter, which is easy to imagine. Second, the bark becomes "human" dimensions: 2 mm thickness now 2 meter high person.

Thus we can go on to 29th street, to the edge of our giant swipe, and it's easy to see what was going on in her two-meter thickness. To demonstrate, let's pull out our giant cubic meter of bark, to explore it, to see what happens in a normal cubic millimeter of real bark.

What we see in this a cubic meter? Hash. Let's clean it and put it back.

First, place the catfish, small bodies of the neurons who live in this cube.

Catfish range in size, but the neuroscientists, with whom I spoke, say that the soma of neurons in the cortex, most often 10-15 microns in diameter (one micron = micron, 1/1000 of a millimeter). That is, if you put 7-10 of these in a line, this line will be the diameter of human hair. In our scale soma will be 1-1,5 cm in diameter. Lollipop.

The volume of the entire crust fits 500 000 cubic millimetres, and this space will be about 20 billion soms. That is, the average cubic millimeter of cortex contains about 40,000 neurons. In terms of our around 40 000 cubic meter of candy. If we divide our box into 40,000 blocks, each with the face 3 of an inch, each of our soma-candy will be at the center of its own 3-inch cube, and all other catfish — 3 inches in all directions.

Are You still here? Can you imagine our metre cube with 40,000 floating candy?

Here microscopic image of soma in the real cortex; everything else around it has been removed:

Okay, so far it looks not so difficult. But soma is only a tiny part of each neuron. From each of our stretch Lollipop, twisted, branched dendrites, which in our scale can take three to four meters in different directions, and may be axon length of 100 meters (if transferred to another part of the crust), or kilometers (if descends in the spinal cord and the body). Each thickness in mm, and these wires make the crust in tightly twisted electrical vermicelli.

This pasta is a lot of things. Each neuron has synaptic connections with a 1000 — sometimes up to 10 000 other neurons. As in the bark of about 20 billion neurons, this means that it will be more than 20 trillion individual neural connections (and a quadrillion connections in the brain). In our cubic meter is more than 20 million synapses.

With all this, not only from each Lollipop from 40 000 in our Cuba come a thicket of vermicelli, but thousands of other spaghetti pass through our cube from other parts of the cortex. And so, if we tried to record signals or to stimulate neurons specifically in this cubic region, we had to be very hard, because in the mess of spaghetti it will be difficult to determine which threads belong to our spaghetti soma-candy (and God forbid, in principle, be Purkinje cells).

And, of course, don't forget about neuroplasticity. The voltage of each neuron changes constantly, hundreds of times per second. And tens of millions of synaptic connections in our cube will constantly change sizes, disappear and appear again.

But this is only the beginning.

It Turns out that in the brain there are also glial cells — cells that are of different types and perform many different functions, such as leaching of chemicals released in the synapses, wrap axons with myelin and maintenance of the immune system of the brain. Here are some of the most common types of glial cells:

How many glial cells are in the cortex? About the same as neurons. So add in our cube 40 000 of these...