The Computer and the Brain is an unfinished book by mathematician John von Neumann, begun shortly before his death. Von Neumann was an important figure in computer science, and the book discusses how the brain can be viewed as a computing machine. The book is speculative in nature, but von Neumann discusses several important differences between brains and computers of his day (such as processing speed and parallelism), as well as suggesting directions for future research.
At only 96 pages, the book was originally intended for Yale's Silliman lectures, but it was published posthumously. The second edition contains a foreword by Paul Churchland and Patricia Churchland that places von Neumann's views in the context of science at that time.
Amazon.com: The Computer and The Brain: Second Edition http://www.amazon.com/Computer-Brain-Silliman-Memorial-Lectures/dp/0300084730/ref=sr_1_5?ie=UTF8&qid=1298758228&sr=8-5