A Thousand Brains: A New Theory of Intelligence

by Jeff Hawkins

The cells in your head are reading these words. Think of how remarkable that is. Cells are simple. A single cell can’t read, or think, or do much of anything. Yet, if we put enough cells together to make a brain, they not only read books, they write them.

I find it amazing that the only thing in the universe that knows the universe exists is the three-pound mass of cells floating in our heads.

Unlike other parts of the brain, none of the cells in the neocortex connect directly to muscles, so it can’t, on its own, make any muscles move. When the neocortex wants to do something, it sends a signal to the old brain, in a sense asking the old brain to do its bidding.

Under one square millimeter of neocortex (about 2.5 cubic millimeters), there are roughly one hundred thousand neurons, five hundred million connections between neurons (called synapses), and several kilometers of axons and dendrites.

The evidence we have indicates that the complex circuitry seen everywhere in the neocortex performs a sensory-motor task. There are no pure motor regions and no pure sensory regions.

Darwin proposed that the diversity of life is due to one basic algorithm. Mountcastle proposed that the diversity of intelligence is also due to one basic algorithm.

Each minicolumn contains a little over one hundred neurons spanning all layers. Unlike the larger cortical column, minicolumns are physically distinct and can often be seen with a microscope.

Being able to learn practically anything requires the brain to work on a universal principle.

These predictions occurred in every sensory modality, for low-level sensory features and high-level concepts, which told me that every part of the neocortex, and therefore every cortical column, was making predictions. Prediction was a ubiquitous function of the neocortex.

The brain creates a predictive model. This just means that the brain continuously predicts what its inputs will be. Prediction isn’t something that the brain does every now and then; it is an intrinsic property that never stops, and it serves an essential role in learning. When the brain’s predictions are verified, that means the brain’s model of the world is accurate. A mis-prediction causes you to attend to the error and update the model.

Tenet Number One: Thoughts, Ideas, and Perceptions Are the Activity of Neurons

Tenet Number Two: Everything We Know Is Stored in the Connections Between Neurons

Now we know a lot about what cortical columns do. We know that each column is a sensory-motor system. We know that each column can learn models of hundreds of objects, and that the models are based on reference frames.

“You should stop talking about hierarchy. It doesn’t really exist.”

“Qualia” is the name for how sensory inputs are perceived, how they feel.

Fear of death and sorrow for loss are not required ingredients for a machine to be conscious or intelligent.

the older parts of the human brain control the basic functions of life. They create our emotions, our desires to survive and procreate, and our innate behaviors. When creating intelligent machines, there is no reason we should replicate all the functions of the human brain.

the only thing that knows that the universe exists at all—is our brain.