What"s going on in there? One of the great scientific and philosophical mysteries is how a few pounds of wet, salty cobwebs can give rise to the rich experience that we call consciousness. Oxford neuroscientist Susan Greenfield peers inside the dimly lit skull to show us what she thinks is going on in The Private Life of the Brain. Greenfield has a facility for explaining tricky scientific concepts in language that can engage any reader. She presents the basics of contemporary thought on consciousness as they relate to her own theory, which involves a continuum of experience between sensual, emotional grounding in the surrounding world and rational, cognitive withdrawal into mental life. Arguing from a wide range of animal and human research, and drawing on the work of philosophers John Searle and Daniel Dennett, she makes her case compellingly but gently, granting that other theories might also hold in this still-uncharted territory. Looking in depth at depression, drug use, and fear, Greenfield shows how each is explained by her continuum theory and how each relates to the life of the human organism as a whole. Could it be true that as our minds work harder, our hearts lose some feeling, and vice versa? It"s an intriguing, thought-provoking idea, one that alone makes The Private Life of the Brain essential reading for minds seeking self-enlightenment. --Rob Lightner