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.

Detailed explanation-2: -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-3: -People typically enter REM sleep within the first 90 minutes of falling asleep. As the sleep cycle repeats, REM sleep occurs several times while a person is resting. In fact, it accounts for approximately 20–25% of an adult’s sleep cycle and over 50% of an infant’s. Most dreams occur during REM sleep.

Detailed explanation-4: -Adults generally average 1-2 hours of deep sleep per night, somewhere between 15 and 25% of your nightly sleep. Most of our deep sleep comes in the first sleep cycle of the night, usually 45-90 minutes. Age has a major effect on how much deep sleep we get each night and how much we need.