A Thousand Brains: A New Theory of Intelligence

It is human nature - aka old brain - to suspect everyone wants to steal your idea, where the reality is that you are lucky if anyone cares about your idea at all.

There are two ways to think about ourselves. One is as biological organisms, products of evolution and natural selection. From this point of view, humans are defined by our genes, and the purpose of life is to replicate them. But we are now emerging from our purely biological past. We have become an intelligent species. We are the first species on Earth to know the size and age of the universe. We are the first species to know how the Earth evolved and how we came to be. We are the first species to develop tools that allow us to explore the universe and learn its secrets. From this point of view, humans are defined by our intelligence and our knowledge, not by our genes. The choice we face as we think about the future is, should we continue to be driven by our biological past or choose instead to embrace our newly emerged intelligence?

At some point in the future, we will accept that any system that learns a model of the world, continuously remembers the states of that model, and recalls the remembered states will be conscious.

through the sensory nerves. The nerves only send spikes. And since we do not perceive spikes, everything we do perceive must be fabricated in the brain. Even the most basic feelings of light, sound, and touch are creations of the brain; they only exist in its model of the world.

We are intelligent not because we can do one thing particularly well, but because we can learn to do practically anything.

life is not about having a correct model of the world. Life is about replication.

There are neurons in the old part of our brain that are known to learn maps of the places we have visited, and these neurons have been under evolutionary pressure for so long that they are fine-tuned to do what they do. In mammals, the old brain parts where these map-creating neurons exist are called the hippocampus and the entorhinal cortex.

However, if one or more of the neurons are in the predictive state, our theory says, only those neurons spike and the other neurons are inhibited. Thus, when an input arrives that is unexpected, multiple neurons fire at once. If the input is predicted, then only the predictive-state neurons become active. This is a common observation about the neocortex: unexpected inputs cause a lot more activity than expected ones.

To predict the next note, you can’t just look at the previous note or the previous five notes. The correct prediction may rely on notes that occurred a long time ago.

Uploading your brain entails recording all the details of your brain, and then using them to simulate your brain on a computer. The simulator would be identical to your brain, so “you” would then live in the computer. The goal is to separate your mental and intellectual “you” from your biological body. This way, you can live indefinitely, including in a computer that is remote from Earth. You wouldn’t die if Earth became uninhabitable.

We have learned a tremendous amount of knowledge and facts about the brain, but we have little understanding of how the whole thing works.

The point is that anything capable of self-replication, especially viruses and bacteria, is a potential existential threat. Intelligence, on its own, is not.

The unit of processing in the neocortex is the cortical column. Each column is a complete sensory-motor system—that is, it gets inputs and it can generate behaviors.

The difficult part of knowledge is not stating a fact, but representing that fact in a useful way.

We realized that the brain’s model of the world is built using maplike reference frames. Not one reference frame, but hundreds of thousands of them. Indeed, we now understand that most of the cells in your neocortex are dedicated to creating and manipulating reference frames, which the brain uses to plan and think.

In the battle between the old brain and the neocortex, the old brain usually wins. We eat the cake.

The list of things everyone should know is short. I would include how the brain is composed of the new part and the older parts. I would include how the neocortex learns a model of the world, whereas the older parts of the brain generate our emotions and more primitive behaviors. I would include how the old brain can take control, causing us to act in ways we know we shouldn’t. And I would include how all of us are susceptible to false beliefs and how some beliefs are viral.

we learn by moving. In order to learn a model of a building, we must walk through it, going from room to room. To learn a new tool, we must hold it in our hand, turning it this way and that, looking and attending to different parts with our fingers and eyes. At a basic level, to learn a model of the world requires moving one or more sensors relative to the things in the world.

Although we can’t know the details of the future, the Thousand Brains Theory can help us define the boundaries. Understanding how the brain creates intelligence tells us what things are possible, what things are not, and to some extent what advances are likely.

Knowledge in the brain is distributed. Nothing we know is stored in one place, such as one cell or one column. Nor is anything stored everywhere, like in a hologram. Knowledge of something is distributed in thousands of columns, but these are a small subset of all the columns.

A future driven by genes has little to no direction and only short-term goals: stay healthy, have kids, enjoy life. A future designed in the best interest of knowledge has both direction and end goals.

Our neocortex has invented powerful technologies that are capable of changing the entire Earth, but the human behavior that controls these world-changing technologies is often dominated by the selfish and shortsighted old brain.

Our reality is similar to the brain-in-a-vat hypothesis; we live in a simulated world, but it is not in a computer—it is in our head.