Contemporary culture increasingly suffers from problems of attention, over-stimulation, and stress, and a variety of personal and social discontents generated by deceptive body images. This book argues that improved body consciousness can relieve these problems and enhance one's knowledge, performance, and pleasure.
In the R&K standard, NREM sleep was divided into four stages, with slow-wave sleep comprising stages 3 and 4. In stage 3, delta waves made up less than 50% of the total wave patterns, while they made up more than 50% in stage 4. Furthermore, REM sleep was sometimes referred to as stage 5. In 2004, the AASM commissioned the AASM Visual Scoring Task Force to review the R&K scoring system.
The five stages of sleep, including their repetition, occur cyclically. The first cycle, which ends after the completion of the first REM stage, usually lasts for 100 minutes. Each subsequent cycle lasts longer, as its respective REM stage extends. So a person may complete five cycles in a typical night's sleep.