Originally published in 1982, this book provides rich evidence of the relevance of the temporal aspects of behavior. The generalized areas of learning, memory, operant scheduled behavior, task performance, vigilance, mood and motivation and their rhythmic components are explored in varying detail. The particularized measures range from on-the-job errors, through reading efficiency to milliseconds of change in reaction time in the laboratory. The subjects range from ants to older persons. Across this range of settings, subjects, and behaviors, the message is clear: there is an interaction between time and behavior.