Why do we need to sleep? What are the purpose of dreams? How does sleep effect cognition?" Sleep and Cognition will "explore the impact of sleep on cognitive performance, drawing evidence from the complementary fields of behavioural neuroscience, cognitive neuroscience and cognitive psychology. Bringing together leading international researchers, the book will provide an essential overview of the relationship between sleep and cognition. Beginning with an introduction to the various functions of sleep, the book will then consider different assessment methodologies, and the range of associated sleep disorders. It is an essential text for all students interested in the psychology of sleep.