How to Create a Mind: The Secret of Human Thought Revealed by Ray Kurzweil Viking, 336 pp., $27.95

According to Wikipedia, Ray Kurzweil is an

American author, inventor, futurist, and director of engineering at Google. Aside from futurology, he is involved in such fields as optical character recognition (OCR), text-to-speech synthesis, speech recognition technology, and electronic keyboard instruments.

So he is a computer engineer specializing in word recognition technology, with a side interest in bold predictions about future machines. He is not a professional neuroscientist or psychologist or philosopher. Yet here we have a book purporting to reveal—no less—“the secret of human thought.” Kurzweil is going to tell us, in no uncertain terms, “how to create a mind”: that is to say, he has a grand theory of the human mind, in which its secrets will be finally revealed.

These are strong claims indeed, and one looks forward eagerly to learning what this new theory will look like. Perhaps at first one feels a little skeptical that Kurzweil has succeeded where so many have failed, but one tries to keep an open mind—hoping the book will justify the hype so blatantly brandished in its title. After all, Kurzweil has honors from three US presidents (so says Wikipedia) and was the “principal inventor of the first CCD flatbed scanner” and other useful devices, as well as receiving many other entrepreneurial awards. He is clearly a man of many parts—but is ultimate theoretician of the mind one of them?

What is this grand theory? It is set out in chapter 3 of the book, “A Model of the Neocortex: The Pattern Recognition Theory of Mind.” One cannot help noting immediately that the theory echoes Kurzweil’s professional achievements as an inventor of word recognition machines: the “secret of human thought” is pattern recognition, as it is implemented in the hardware of the brain. To create a mind therefore we need to create a machine that recognizes patterns, such as letters and words. Calling this the PRTM (pattern recognition theory of mind), Kurzweil outlines what his theory amounts to by reference to the neural architecture of the neocortex, the wrinkled thin outer layer of the brain.

According to him, there are about 300 million neural pattern recognizers in the neocortex, with a distinctive arrangement of dendrites and axons (the tiny fibers that link one neuron to another). A stimulus is presented, say, the letter “A,” and these little brain machines respond by breaking it down into its geometric constituents, which are then processed: thus “A” is analyzed into a horizontal bar and two angled lines meeting at a point. By recognizing each constituent separately, the neural machine can combine them and finally recognize that the stimulus is an instance of the letter “A.” It can then use this information to combine with other letter recognizers to recognize, say, the word “APPLE.” This procedure is said to be “hierarchical,” meaning that it proceeds…