For the lay reader, a British scientist offers an enlightening look at the human brain and mind, clarifying what researchers now know and what difficult and tantalizing questions they are still struggling to answer. In 1994, Greenfield (Pharmacology/Oxford) was asked to give the Royal Institution Christmas Lectures, a popular series aimed at teenagers and broadcast by the BBC. This book, which is aimed at adult readers, derives from that series. In it, the author approaches the brain first as a physical object, exploring its different regions, and then examining certain functions, specifically movement and vision, to demonstrate how these are carried out by the different regions engaging in a kind of ""balanced dialogue."" Greenfield then shifts her approach and tackles the brain from a cellular level. She begins with a single neuron and explains how the brain is built in increasingly complex circuits. She shows how neurons communicate with each other chemically and how this communication is affected by mood-altering drugs such as nicotine, morphine and its derivative heroin, cocaine, and ecstasy. She next turns to the development of the brain from the beginning of life, showing how its neuronal circuitry constantly changes as a result of experience, and tackling the issue of when consciousness arises. In her final chapter she considers the various kinds of memory, raising tough questions about the relationship of brain to mind. Happily for the reader, Greenfield, who recently began giving free public lectures on the brain in the City of London, has developed a keen sense of what curious nonscientists want to know and, equally important, how to impart scientific information with verve and clarity.