Section 2
Sleep and Dreaming
Book
Version 11
By Boundless
By Boundless
Boundless Psychology
Psychology
by Boundless
5 concepts
Introduction to Sleep
Most adults need seven to nine hours of sleep to recuperate from physical exertion, as well as to consolidate learning and memory.
![Thumbnail](../../../../../../figures.boundless-cdn.com/20602/square/200.jpeg)
Circadian Rhythms
Circadian rhythms are physical, mental, and behavioral changes that respond to light and darkness and are important in determining human sleep patterns.
![Thumbnail](../../../../../../figures.boundless-cdn.com/20544/raw/stage2sleep.jpg)
Stages of Sleep
Sleep proceeds through multiple cycles of non-REM (3 stages) and REM per night, with each full cycle lasting between 90 and 110 minutes.
![Thumbnail](../../../../../../figures.boundless-cdn.com/20560/square/sleepy-at-work.jpeg)
Sleep-Wake Disorders
Sleep disorders cause sleep disturbances that affect the amount, quality, or timing of sleep or that induce abnormal events during sleep.
![Thumbnail](../../../../../../figures.boundless-cdn.com/20462/square/-statue-of-eros-sleeping-7.jpeg)
The Nature and Meaning of Dreams
Numerous theories, both psychological and neurobiological, have been proposed to explain the elusive mystery of the purpose of dreaming.