REM (abbr.): Good sleep comes to those who wait

Sleep—there’s just never enough to go around. And though most of us keep meaning to change that, it doesn’t often get crossed off our to-do lists. As it turns out, a little more sleep, particularly REM (rapid eye movement) sleep, would help us with a lot of our to-dos—including problem solving. Scientists are still unsure of all the benefits of REM sleep, but some say it developed because we needed to be alert to nearby predators. Others think it developed due to our constant need to eat. Whatever its origin, REM sleep is as vital today as it was in our less upright days. Here’s a look at REM and how it fits into our sleep cycle.

A Relatively New Discovery

REM sleep was first researched in 1953 when scientists studied a group of children who had difficulties sleeping. During the research, the scientists observed that the sleeping children showed signs of repeated eye movements that resembled the same eye movements they had when awake. The research into sleep cycles has come a long way since 1953, but, as expected, there are varying theories. Some scientists say there are four stages in our sleep cycle, while others say there are five. REM is the last stage of the cycle.

How the Cycle Works

When we turn down the bed and snuggle under the covers, we embark on a sleep cycle that repeats itself about every 110 minutes until we wake. The first stage of that cycle begins with non-rapid eye movement stages (NREM). In this first stage, our eyes are closed, but we are aware of our surroundings. In the second stage of NREM, we drift off into a state where our heart rate slows and our body temperature dips. In the third stage, our brain waves slow down substantially and we prepare to enter the realm of that rather elusive deep sleep where practically nothing can wake us. It’s during this deep sleep—stage 3 (or stage 4, depending on your view)—where the body repairs itself, strengthens its immune system and produces proteins that aid the body in healing. Next comes REM sleep and dream time.

Dream Time

About 90 minutes after entering deep sleep, REM starts and our eyes begin to do the “tennis match shuffle.” In this stage of the sleep cycle, our respiratory and heart rates increase and we actually become paralyzed. Paralyzed! This paralysis is called muscle atonia, and it functions as a safety mechanism in case we dream something active, such as swimming or fighting. However, in some people this safety mechanism is disabled, and during REM sleep they will do chores and sometimes even unknowingly hurt their sleep partner.

The Benefits

REM sleep is crucial mainly because it helps the brain sort and save the day’s experiences for later recall. Because the brain is more alert while in REM, the outside noises or smells that we subconsciously detect may be transmitted into our dreams. Our brain goes over the day’s activities randomly, which can give us even crazier dreams. However, if we don’t have REM sleep, it diminishes our ability to learn and remember complex tasks. When you first go to bed, the NREM stages are long and REM sleep is short. As morning approaches, those roles are reversed. And if our REM time is disrupted, the next cycle we go through will have longer-than-normal REM sleep until we’re caught up and then we go through the cycle as normal—or as close to it as our snoring partners, noisy neighbours or drippy faucets will allow. Bonne nuit! t8n

Fun Facts

REM sleep is intermittent
(or phasic) and can be monitored by electro-oculography (EOG).

Babies spend about 50%
of their sleep in REM.

Adults spend about 25%
of their sleep in REM.

Did You Know?

Cold-blooded animals and reptiles don’t engage in REM sleep; only humans, mammals and birds do.

When brain waves are measured in a person during REM sleep, they resemble those of a person awake.

People spend, on average, two hours a night dreaming.