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. The entire sequence from drowsiness to deep stage IV sleep usually takes about an hour.

Detailed explanation-2: -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.

Detailed explanation-3: -Sleep in adults Stage N2 occurs throughout the sleep period and represents 45–55% of total sleep time. Stage N3 (slow-wave sleep) occurs mostly in the first third of the night and constitutes 10–20% of total sleep time. REM represents 20–25% of total sleep time and occurs in 4–5 episodes throughout the night.

Detailed explanation-4: -Stage N3 is deep sleep and lasts about 20 to 40 minutes. During this stage, delta brain activity increases and you may have some body movements. It is very hard to wake up someone in stage N3.

Detailed explanation-5: -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). During this time, an individual’s heart rate and respiration slow dramatically.