AP PSYCHOLOGY

Detailed explanation-1: -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).

Detailed explanation-2: -For most adults, REM takes up about 20 to 25 percent of sleep, and this seems to be healthy during average sleep cycles.

Detailed explanation-3: -On average you’ll go through 3-5 REM cycles per night, with each episode getting longer as the night progresses. The final one may last roughly an hour. For healthy adults, spending 20-25% of your time asleep in the REM stage is a good goal. If you get 7-8 hours of sleep, around 90 minutes of that should be REM.

Detailed explanation-4: -Stage 2 non-REM sleep is a period of light sleep before you enter deeper sleep, lasts roughly 20 minutes. Stage two is characterized by further slowing of both the heartbeat and breathing, and the brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles.

Detailed explanation-5: -What Is REM Sleep? Usually, REM sleep happens 90 minutes after you fall asleep. The first period of REM typically lasts 10 minutes. Each of your later REM stages gets longer, and the final one may last up to an hour.