This book is structured into four sections, each with two or three chapters by specialists in the field. Section I is concerned with sleepiness as a transition state between wakefulness (i.e. performance) and sleep. Terry Pivik's chapter first discusses several qualities of sleepiness, giving us a psychophysiological perspective on the issue and introducing many of the concepts discussed in later chapters. Two chapters then follow which relate to circadian rhythm issues concerning the transition state. The editor's chapter is concerned with subjective sleepiness, its circadian underpinnings, and its role as a circadian messenger, precipitating the onset of sleep. Peretz Lavie discusses the "gates to sleep" represented by the 24 hour sleep propensity function, describing some novel findings from studies using ultra-short sleep-wake cycles. Section II contains two chapters concerned with the performance of individuals who are sleepy. David Dinges and Nancy Kribbs provide a comprehensive review of laboratory sleep deprivation studies and Torbjorn Akerstedt discusses "sleepiness at work" giving examples from his own studies.
Section III is concerned with sleep loss and sleepiness and consists of two chapters from specialists who happen to disagree on this issue. Mary Carskadon and Tom Roth lead off with a chapter on sleep restriction which advances the view that many of us are partially sleep deprived on a chronic basis. In the following chapter Jim Horne argues that although there is a "core" amount of sleep necessary for cognitive restitution, the remainder of sleep we habitually obtain is "optional" leading to a different form of "sleepiness". Section IV is concerned with clinical aspects of sleep, sleepiness and performance. Tom Neylan and Chip Reynolds lead off with a discussion of pathological sleepiness - the presence of sleepiness at a time when it is not wanted. Cindy Dorsey then discusses the other side of the coin - the absence of sleepiness when it is wanted. Both chapters discuss the clinical conditions that can lead to such problems and the treatment strategies used to alleviate them.
Finally, Dan Buysse gives a comprehensive review of the various drugs and pharmacological agents ("uppers" and "downers") that affect sleep, sleepiness and performance, discussing their effects and mode of action.