Wednesday, November 01, 2006

Thinking Machines

Continued from page 1

By Jason Pontin

TR: How is your philosophy of artificial intelligence different from Marvin Minsky's famous "society of mind"?

Hillis: Marvin is my mentor, so any philosophy of AI that I have starts with his. I was living in his basement while he was writing the book Society of Mind, and every day he would write a new page or two and let me read it. Then we would get to talk about it, and I would get to hear all the thought that he had put behind it. I still can't imagine what it would be like to read that book, cover to cover, without a long conversation on each page. But that is the point of the book: as Marvin would put it, "The brain is a kludge." There are a lot of different things going on, and they interact in complicated ways. Marvin is surely wrong on most of the details, but I think the big picture of lots of different, loosely coupled semi­autonomous processes is basically right.

TR: You were ahead of your time in applying computation to immunology, genetics, and neurobiology. Today, computation is ubiquitous in biology. What will this mean?

Hillis: I am excited that computational biology is coming into its own. It feels like the field of computing did in 1970. Everything seems pos­sible, and the only constraint is our imagination. There are still so many basic, simple questions that are unanswered: "How are memories encoded?" "How does the immune system have a sense of 'self'?"

I am especially interested in what will come of computational models of evolution, although I have to admit that the field seems a bit stuck right now. Most current models of evolution reduce it to a very weak kind of search algorithm, but I have always felt that there is something more to it than that. It is not that the biologists are wrong about the mechanisms, but rather that the models are much simpler than the biology. It may be that the interaction of evolution and development is the key, or behavior and environment, or something like that.