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: -In the deepest level of sleep, stage IV sleep, the predominant EEG activity consists of low frequency (1–4 Hz), high-amplitude fluctuations called delta waves, the characteristic slow waves for which this phase of sleep is named.

Detailed explanation-3: -Deep sleep, also called slow-wave sleep, occurs in the third stage of non-rapid eye movement (NREM) sleep. During deep sleep, electrical activity in the brain appears in long, slow waves called delta waves. These waves have a frequency of 0.5 to 2 Hertz.

Detailed explanation-4: -N3 is also known as slow-wave sleep (SWS). This is considered the deepest stage of sleep and is characterized by signals with much lower frequencies and higher amplitudes, known as delta waves. This stage is the most difficult to awaken from, and, for some people, even loud noises (> 100 decibels) will not awaken them.

Detailed explanation-5: -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).