Bringing order and relevance to the cascade of recent brain findings, Dr John Ratey explains the brain's most important systems, the role they play in determining how we interact with the world and the ways in which we can influence their operations for the better. Throughout, he illustrates his points with vivid and often surprising examples drawn from his own practice, research and everyday life. Ratey answers such questions as: What does it mean to be linguistically ambidextrous? How does a mother's cradling of her child on her left shoulder relate to the development of language skills? Why does listening to music while doing homework improve accuracy? Why do people like spicy foods? Ratey also analyses the ways in which things can go wrong, detailing causes and treatments for diseases such as autism, Parkinson's and Alzheimer's, as well as numerous neurological disorders. As Dr Ratey demonstrates throughout the book, the brain is astonishingly flexible, able to be retrained and reprogrammed. Like a muscle, it responds to use, adapting to new demands and conditions, allowing, as the title of the book suggests, the guidance of the user.