In this volume, leading investigators analyze napping patterns and daytime sleepiness in humans and assess the value of napping as a solution to problems of daytime alertness. After reviewing what is currently known about polyphasic sleep in mammals, the contributors examine the development of human napping and present results of sleep latency studies showing that from adolescence onward, pronounced sleepiness occurs in the middle of the day. Other contributors discuss the chronobiological and ultradian aspects of napping and describe napping patterns observed in time-free environments. Extensive findings are presented on napping patterns in adults and on the effects of napping on performance during prolonged work periods and in shift workers. Full consideration is also given to cultural views on napping and the siesta. The book also includes a chapter on daytime sleep episodes, naps, and sleepiness in individuals with medical sleep disorders. (Product Description).