This book shows how the latest scans, which reveal thoughts, memories - even our moods - as clearly as an X-ray reveals our bones, can be used to help explain aspects of our behaviour, and how behavioural eccentricities can be traced to abnormalities in an individual brain. Dyslexia, for example, may be caused by a short-circuit in the messages converting sound to visual cues ; addiction, eating disorders and alcoholism stem from dysfunction in the brain's reward system ; violent criminals may begin life with a small neurological fault.