AP PSYCHOLOGY

Detailed explanation-1: -These four sleep stages are called non-rapid eye movement (non-REM) sleep, and its most prominent feature is the slow-wave (stage IV) sleep. It is most difficult to awaken people from slow-wave sleep; hence it is considered to be the deepest stage of sleep.

Detailed explanation-2: -Stage 4-REM Sleep The first round of REM in a night lasts about 10 minutes, with the stage getting longer and longer each time you enter REM in one night1. It’s also the deepest stage of sleep, where you’ll experience1: Quickened breathing. Faster heart rate and blood pressure.

Detailed explanation-3: -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-4: -NREM stage 1 progresses into NREM stage 2. NREM stage 2 is followed by NREM stage 3. NREM stage 2 is then repeated. Finally, you are in REM sleep.

Detailed explanation-5: -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.