PSYCHOLOGY OF EMOTIONS

Detailed explanation-1: -On the one hand, during NREM sleep, brain activity is organized by spontaneous coalescent cerebral rhythms: spindles and slow waves. On the other hand, phasic activity during REM sleep is characterized by ponto-geniculo-occipital (PGO) waves, named according to their most frequent sites of recording in animals.

Detailed explanation-2: -NREM sleep constitutes about 75 to 80 percent of total time spent in sleep, and REM sleep constitutes the remaining 20 to 25 percent. The average length of the first NREM-REM sleep cycle is 70 to 100 minutes. The second, and later, cycles are longer lasting-approximately 90 to 120 minutes (Carskadon and Dement, 2005).

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: -NREM sleep exhibits a significant increase of delta range activity, as well as an increase in amplitude. REM sleep is defined by the strong synchronous theta range (7–9 Hz) activity, probably generated in the hippocampus.