This unique and up-to-date book provides a comprehensive history and critical account of sleep mentation research since the introduction of electrographic techniques. Written by leading experts, it not only examines the activity of the mind during sleep but also scrutinizes methodological issues of key importance to the field. Looks at the relationships between physiological and mental events as brought to light by electrographic and other controlled studies of sleep mentation. Rigorously organized around topics of common interest, it is a penetrating study of current developments in the field. Chapters are devoted to critical reviews of REM deprivation studies, the relationships between sustained and short-lived physiological conditions and sleep mentation, clinical phenomena such as sleep-talking, nightmares and night-terrors.