An article in the Proceedings of the National Academy of Science by Cornell psycholinguist Michael Spivey got Slashdotted and mentioned in a few news sources yesterday. The first paragraph of the stories tended to sound like this:

The theory that the mind works like a computer, in a series of distinct stages, was an important steppingstone in cognitive science, but it has outlived its usefulness, concludes a new Cornell University study. Instead, the mind should be thought of more as working the way biological organisms do: as a dynamic continuum, cascading through shades of grey.

What I don't understand is what this is supposed to say about the relationship between brains and computers. At the very lowest level, my impression was that we were already sure there were no 'bits' and no clock forcing the brain to perform operations in 'cycles', as in a CPU. At higher levels, there's really nothing tying computers to representations which utilize discrete states.

The fact that the data fit the dynamical system so nicely is very interesting. Which is to say, I'm slowly building a stack of reasons to be interested in dynamical systems. I've checked this book on dynamical systems out of the library twice now, and only read about a chapter. But the source of my interest has been artificial intelligence -- a professor convinced me that to do anything interesting in neural nets I would want to know dynamical systems. So the applicability of these mathematics to cognitive science isn't news.

The news is that language processing specifically does not involve a process whereby some system in the brain discriminates words and releases the results to other systems only when a complete decision is made. This is a pretty cool contribution to an understanding of language and cognition, but you wouldn't know it from reading the news articles. You wouldn't even really understand the conclusion.

Unfortunately, the headlines which the paper generated do little but reinforce silly misunderstandings. The best way to think of a brain is still as some sort of computer. The example at hand is the process by way of which the brain takes input from the ears, and through some process ends up with a representation which causes the subject to press a button. No one seriously believes it's a digital computer, or uses a von Neumann architecture. It's not an interesting statement to say that a brain acts 'like a biological organism', and it's not meaningful to oppose biological organisms to computers, because the relevant notion of computation is much broader than that which applies specifically to the Dell on your desktop.

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