REM Sleep and Dreaming: The Connection

REM sleep is recognized by tiny twitches of facial muscles and slight movements of the hands. During this stage, blood pressure rises, breathing and heartbeat become faster, and the eyes dart rapidly around under closed eyelids as if looking at a moving object. In men, REM sleep can also cause an erection. Researchers have discovered that when sleepers are awakened during REM sleep, they typically report having been dreaming. (You may also feel temporarily paralyzed if awakened during this stage, which can explain phenomena such as the succubus, incubus, and alien abduction experiences.)

Dreams and the REM Cycle

Most of the dreams you remember occur during the REM stage when the brain is fully active. After about ten minutes of REM, you enter stages two, three, and four of the sleep cycle again, and continue moving backwards and forwards through the cycle. As the night progresses, however, the REM phases become longer, with the longest lasting around thirty to forty-five minutes. Although dreams occur during both REM and NREM stages, the final REM stages are the ones you are most likely to remember.

How Much Sleep Do We Need?

We spend approximately one-third of our life asleep, meaning that by the time we reach the age of ninety, we will have spent about thirty years asleep. The exact amount of sleep each person needs depends on factors such as age and activity level. Babies typically sleep around fourteen hours a day, while teenagers need about nine hours. Most adults need an average of eight hours, although some may function well on as few as five hours or as many as ten. Older adults tend to need around six hours of sleep per night.

The Importance of Sleep

Because sleep and dreaming are crucial for well-being, your brain may sometimes demand the sleep it needs to prevent mental or physical overload. This is why you might find yourself nodding off unexpectedly while traveling or watching TV.

Why Sleep Is Essential for Survival

Research on sleep-deprived animals shows that sleep is vital for survival. For example, while rats normally live two to three years, those deprived of REM sleep survive only about five weeks, and those deprived of all sleep stages survive only about three weeks. Other studies have shown that people repeatedly awoken during REM sleep become anxious, irritable, and bad-tempered, suggesting that sleep is essential for physical rest and repair, while REM sleep is crucial for emotional well-being.

Although the exact reasons we sleep and dream remain uncertain, it is possible to conclude that one of the reasons we sleep is to dream.