PSYCHOLOGY OF EMOTIONS

Detailed explanation-1: -These four sleep stages are called non-rapid eye movement (non-REM) sleep, and its most prominent feature is the slow-wave (stage IV) sleep. It is most difficult to awaken people from slow-wave sleep; hence it is considered to be the deepest stage of sleep.

Detailed explanation-2: -Deep sleep is sometimes known as ‘slow-wave sleep’ because of the long, slow delta waves produced by our brains during these final two sleep stages 5. You’ll usually enter the third stage within an hour of falling asleep. If you wake up at this point, you’re more likely to feel groggy for around an hour afterwards 5.

Detailed explanation-3: -Stage 4: REM Sleep While your brain is aroused with mental activities during REM sleep, the fourth stage of sleep, your voluntary muscles become immobilized. Your brain also uses this time to cement information into memory, making it an important stage for learning.

Detailed explanation-4: -In general, each cycle moves sequentially through each of the 4 stages of sleep: wake, light sleep, deep sleep, REM, and repeat. Cycles earlier in the night tend to have more deep sleep while later cycles have a higher proportion of REM. By the final cycle, your body may even choose to skip deep sleep altogether.

Detailed explanation-5: -Stage 3 and 4 sleep, the most restorative stages, are known as deep sleep. We need about one and a half to two hours of deep sleep a night. In stage 3, very slow brain waves called delta waves are interspersed with smaller, faster waves. By stage 4, the brain almost exclusively produces delta waves.