When IBM's Deep Blue supercomputer edged out world chess champion Garry Kasparov during their celebrated match in 1997, it did so by means of sheer brute force. The machine evaluated some 200 million potential board moves a second, whereas its flesh-and-blood opponent considered only three each second, at most. But despite Deep Blue's victory, computers are no real competition for the human brain in areas such as vision, hearing, pattern recognition, and learning. Computers, for instance, cannot match our ability to recognize a friend from a distance merely by the way he walks. And when it comes to operational efficiency, there is no contest at all. A typical room-size supercomputer weighs roughly 1,000 times more, occupies 10,000 times more space and consumes a millionfold more power than does the cantaloupe-size lump of neural tissue that makes up the brain.
How does the brain--which transmits chemical signals between neurons in a relatively sluggish thousandth of a second--end up performing some tasks faster and more efficiently than the most powerful digital processors? The secret appears to reside in how the brain organizes its slow-acting electrical components.