Sunday, February 18, 2018

Stuff I've Been Working on: The Cortical Column

The Cortical Column

Understanding the organization and function of the cortical column is essential to figuring out how the brain works. What follows are partial results of my brain/intelligence research over the years. Unlike deep neural nets, the brain can instantly see a complex object that it has never seen before. How does it do it? It learns lots of small elementary patterns (lines, edges, bits of sounds, etc.) by creating simple sensors that reside in the thalamus.

All elementary patterns come in opposite/complementary pairs. They are the building blocks of all objects. The brain can instantly reuse them to detect any complex object on the fly. This is crucial to survival. Object detection is the job of millions of cortical columns. These are organized into two yin-yang or mirror hierarchies of up to 20 levels. The object detection process is fast and simple and requires little computation. Signals from pattern detectors simply percolate up the hierarchy according to their temporal signatures. An entire detection process, from elementary pattern detections to recognition feedback signals, takes about 10 milliseconds.

Each column can learn dozens of small pattern combinations stored in minicolumns. The combinations in every column revolve around a single pattern detector called the primary input. Only one combination can be detected at a time. Each minicolumn has one output that is sent to a higher layer. Each also receives a feedback connection from the layer above it. Feedback signals are recognition events that serve to correct incomplete pattern detections. How the combinations are learned is the topic for a future article.

The cortical hierarchy is a magnificent machine. It can do all sorts of beautiful and wonderful things that I cannot go into in this article. I will conclude by adding that an activated topmost minicolumn in the knowledge tree (a branch) represents a complex sensed object or pattern at a point in time.

I don't know when but there will be more to come. Stay tuned.


Peter ( said...

Good work Louis! Keep it up! I'm very busy myself too, but I'm definitely keeping my eye on rebelscience. Daily, most of the times, in fact.

How it learns is of course what I'm interested in the most, as is selecting what is relevant to learn :) very hard problems if you ask me.

Louis Savain said...

Thanks, Peter. I'm writing an article on the purpose of corticothalamic feedback signals. It will explain why feedback signals are essential to learning in cortical columns and why REM sleep is also vital to cortical learning.