Book review of Jeff Hawkins

Jeff Hawkins:
ON INTELLIGENCE (Henry Holt, 2004)
(Copyright © 2009 Piero Scaruffi | Legal restrictions - Termini d'uso )

Vernon Mountcastle, the USA neurophysiologist who had discovered the columnar organization of the cerebral cortex, pointed out that the neocortex is uniform ("An Organizing Principle for Cerebral Function", 1978): there is no indication that any region of the neocortex operates differently from the other regions. That is puzzling because, at the end, some regions generate images and others generate sounds. The difference in "output", though, must be due almost entirely to the different inputs, because there is nothing inherently different between the regions that process one and the other. Furthermore, the inputs all comply with the exact same standard: they are all electrochemical signals. There is nothing inherently different in the format or in the processing. What is different is the pattern: spatial patterns, that are coincident patterns in time, and temporal patterns. The vision of something and the hearing of something are created in the brain by analyzing a stream of patterns. It is the brain that seens, not the eye. It is the brain that hears, not the ear.

That's the starting point for Hawkins' theory that mostly recycles old theories.

Notably, he revises Roger Schank's theory of scripts and its predictive model of memory. The brain doesn't simply process inputs and merge them at higher and higher levels, but at the same time does also the opposite: it predicts what comes next. This is how it can recognize events, situations and people, and understand what is going on. Memory is bidirectional: memory interprets the present while it is absorbing it. At the same time the memory of the past is tweaked every time we use it, based on the result of using it. Memory becomes a reservoir of possible solutions to problems. Memory constantly predicts what will happen next. That's how it can keep track of situations that would require almost infinite computational capabilities.

Hawkins believes that the columnar structure of the neocortex yields a hierarchical structure of mind (lower levels being closer to raw perception, and higher levels being closer to pure abstraction). At each level the basic form of processing is a combination of matching and creating patterns. Perception, action and cognition are spread throughout this hierarchy of patterns. The brain's function is to store memories as patterns and to make predictions based on such patterns. The brain is fundamentally a forecasting machine, that continuously analyzes the present (current patterns) against the past (stored patterns) in order to predict the future.