We spend about one-third of our lives sleeping. For many animals, sleep represents a time of vulnerability. Some species even developed special defenses against danger from predators while they slept. Dolphins and many species of ducks and birds show “split brain” activity, where one half of the brain sleeps while the other half remains alert for dangers or performs basic movements like swimming or flipper movement to remain afloat.
If sleep is such a dangerous time, then why do we do it?
Research into the purpose of sleep looked first at what happens when sleep is disturbed. Studies have shown correlations between certain sleep disturbances and future health problems. Sleep and dreaming appear to play a role in memory consolidation and learning. Problem-solving may even occur during sleep. Have you ever awakened and found you “magically” have the solution to a problem?