PSYCHOLOGY OF EMOTIONS

Detailed explanation-1: -Deep, slow brain waves known as delta waves begin to emerge during NREM stage 3 sleep-a stage that is also referred to as delta sleep. This is a period of deep sleep where any environmental noises or activity may fail to wake the sleeping person.

Detailed explanation-2: -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-3: -The majority of brain waves during stage 3 NREM sleep are called delta waves. These are large waves with a relatively slow frequency of 1 to 4 Hertz. Stage 3 NREM sleep also displays so-called slow oscillations, which are even slower at 0.5 to 1 Hertz.

Detailed explanation-4: -Together, NREM sleep stages 3 and 4 are often known as slow wave sleep (SWS).

Detailed explanation-5: -NREM and REM Sleep Cycles A sleep episode begins with a short period of NREM stage 1 progressing through stage 2, followed by stages 3 and 4 and finally to REM.