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.
Light and Deep Sleep. During sleep, you alternate between cycles of REM (rapid eye movement) and NREM (non-rapid eye movement) that repeat about every 90 minutes. You spend about 75 percent of the night in NREM sleep, which consists of four stages of increasing relaxation. Stage one, or the phase between being awake and asleep, is considered light sleep. Deeper sleep begins in stage two, as your breathing and heart rate become regular and your body temperature drops.