Spiritual Machines

I'm in the middle of re-reading The Age of Spiritual Machines by Ray Kurzweil. It's a very interesting read: all about what might (will?) happen in the very near future when computers are able to process information as fast as or faster than the human brain. Will they begin to actually think? Will they become self-aware? Will they grow a conscience? Will they, as the title suggests, become spiritual?

One of the things I found most fascinating was his descriptions of how the human brain works — sometimes he puts this process into computer terms, which is good for geeks like me. This particular part stuck with me:

When a batter hits a fly ball, it follows a path that can be predicted from the ball's initial trajectory, spin, and speed, as well as wind conditions. The outfielder, however, is unable to measure any of these properties directly and has to infer them from his angle of observation. To predict where the ball will go, and where the fielder should also go, would appear to require the solution of a rather overwhelming set of complex simultaneous equations. These equations need to be constantly recomputed as new visual data streams in. How does a ten-year-old Little Leaguer accomplish this, with no computer, no calculator, no pen and paper, having taken no calculus classes, and having only a few seconds of time?

The answer is, she doesn't. She uses her neural nets' pattern-recognition abilities, which provide the foundation for much of skill formation. The neural nets of the ten-year-old have had a lot of practice in comparing the observed flight of the ball to her own actions. Once she has learned the skill, it becomes second nature, meaning that she has no idea how she does it. Her neural nets have gained all the insights needed: Take a step back if the ball has gone above my field of view; take a step forward if the ball is below a certain level in my field of view and no longer rising, and so on. The human ballplayer is not mentally computing equations. Nor is there any such computation going on unconsciously in the player's brain. What is going on is pattern recognition, the foundation of most human thought.

One key to intelligence is knowing what not to compute. A successful person isn't necessarily better than her less successful peers at solving problems; her pattern recognition facilities have just learned what problems are worth solving.

It should be somewhat obvious, but it was a bit of a revelation to me when I first read it. Now it seems that with neural net software, computers are starting to do pattern recognition almost as well as humans. Kurzweil talks in this book (which is 6 years old, BTW) about computers that can transcribe human speech (spoken at a normal speed) with almost perfect accuracy, and computers that can recognize faces — to the point where some banks trust their computers to perform face recognition on people to provide automatic cheque cashing, i.e. if the computer fails, real money is being given to the wrong people. The bank would have to be pretty damn confident in the face recognition software to make that puppy available to the general public.