How Your Brain Computes
It’s Simple but Deceivingly Clever
Every neural system in every animal finds clever ways to accomplish one feat. And that one computational feat is all you need to know to see completely how your brain works.
It is so basic and fundamental that it is hard to talk about because it is so obvious. But this feat is repeated by hundreds of millions of little computation engines in your skull when perceiving, remembering, and thinking everything that you can perceive, remember or think, or doing anything you can do.
The Unit of Nervous System Computation
What is that one thing? What is that unit of computation? It came to me, as a computational cognitive neuroscientist, back over 50 years ago. I was not alone. That feat goes by many names in English. Examples are “a recognition”, “a discrimination”, “a classification”, or “detecting a signal.“ It’s what your nerves do for a living.
The math for the feat is simple. It is a function that takes a bunch of input signals and outputs a bunch of new signals that are true or right for that context.
I’ll call it a Psi Function Ψ, which takes as inputs signals that are useful for a discrimination or classification of the sources of those signals and as output a ordered set of decisions about…
