AP PSYCHOLOGY

Detailed explanation-1: -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-2: -Stage 3 is often referred to as deep sleep or slow-wave sleep because this stage is characterized by low frequency (less than 3 Hz), high amplitude delta waves (Figure SC. 10).

Detailed explanation-3: -SWS, or delta sleep, follows stage 2 sleep and is characterized by polymorphic, semirhythmic delta waves accounting for at least 20% of the EEG activity. SWS is characterized by relative body immobility. SWS is maximal in young children and markedly decreases with age.

Detailed explanation-4: -3.1. Delta waves are the slowest recorded brain waves in human beings. They are found most often in infants and young children, and are associated with the deepest levels of relaxation and restorative, healing sleep.

Detailed explanation-5: -Delta waves are associated with the deep sleep stages: stage 3 and REM. During stage 3, less than half of brain waves consist of delta waves, while more than half of brain activity consists of delta waves during REM sleep.