AP PSYCHOLOGY

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.

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: -Sleep occurs in five stages: wake, N1, N2, N3, and REM. Stages N1 to N3 are considered non-rapid eye movement (NREM) sleep, with each stage a progressively deeper sleep.

Detailed explanation-4: -Stage 4: REM sleep Your eyes move quickly from side to side during REM sleep. In REM sleep, your brain waves and eye movements increase. Your heart rate and breathing also speed up. Dreaming often happens during REM sleep.

Detailed explanation-5: -Stage 3 sleep is also known as N3 or deep sleep, and it is harder to wake someone up if they are in this phase. Muscle tone, pulse, and breathing rate decrease in N3 sleep as the body relaxes even further. The brain activity during this period has an identifiable pattern of what are known as delta waves.