There are 4 stages of sleep that people undergo throughout each sleep cycle, which typically lasts about 90 minutes.
There is light sleep, which is characterized by low frequency brain waves. This state acts as a transitional phase into the deeper sleep states.
Deep sleep, sometimes called slow wave sleep, is another stage of sleep and is somewhat similar to light sleep. Yet, it is marked by considerably lower frequency brain waves and only takes up about 20% of our overall sleep time. Nonetheless, it is one of the densest, most restorative phases of sleep.
Why Is REM Sleep So Important and What Does It Do?
REM Sleep, is totally different from the other stages of sleep. It is often considered the most mysterious and paradoxical state of sleep and has thus aroused much speculation on its underlying importance.
In this article, we discuss 5 facts concerning REM sleep, focusing on how these facts set REM sleep apart from the other sleep states.
Mimics Waking Consciousness
REM Sleep is unique in that it does not feature low frequency brain waves but instead mixed, even higher frequency brain waves that imitate our normal waking consciousness.
Consequently, muscle tension usually drops to prevent the sleeper from acting out their states of consciousness, which usually feature vivid, realistic dreaming.
Some dreamers even report the ability to lucid dream during REM sleep, which allows them to not only become aware that they are dreaming, but also to control the dream
REM Stands for Rapid Eye Movement
During REM sleep, the eyes of the sleeper are known to dart back and forth. Ultimately, researchers are still uncertain as to why this movement occurs, especially when the rest of the body is effectively paralyzed.
Some theories have proposed that each time the eyes move, a new image or state is elicited during dreaming. This could mean that eye movement is either an epiphenomenon of quickly changing dream states, or perhaps that it is a primary mechanism that allows the body to alter its dream state.
REM Sleep is Found in Other Animals
REM has been discovered to exist in many other animals, not only mammals but also birds. This means that it is not a purely human state, but instead plays an important role in all existence.
Some theories have posited that REM sleep played an important role in the development of warm-bloodedness in animals, since cold-blooded animals do not experience REM sleep.
Still, the REM stages of human sleep differ considerably from those of other animals.
REM Deprivation Leads to Subsequent Increase
Researchers have shown that sleepers who are deprived off REM Sleep earlier in the night tend to experience an increase in REM sleep either later in the night, or an increase during the following night of sleep.
Additionally, many sleepers also experience an increase in slow-wave sleep to offset the lack of REM sleep.
This seems to indicate that all stages of the sleep cycle are interconnected, and that any imbalance in one part will result in a compensation by the body. Thus, you might be able to run from your dreams, but eventually, they’ll find you.
REM Sleep Behavior Disorder
REM Sleep Behavior Disorder is characterized by loss of muscle atonia, which means that when sleepers enter the REM stage, they are not as paralyzed as they usually are, which can lead to muscle twitches or even complicated, more aggressive movements.
This is an interesting disorder because despite its danger, it represents as close as humans can get to waking consciousness on a biophysical level while asleep.
Some researchers speculate that during REM sleep, our muscles are paralyzed precisely to allow for deeper, more vivid dreaming, which can be beneficial for problem-solving and memory consolidation.
Other researchers posit that our muscle paralysis actually limits the possibilities for our underlying brain states during REM sleep. Thus, when these limits are lifted during REM Sleep Behavior Disorder, they actually represent the body attempting to transcend many of its previous confinements, perhaps even seeking more optimal brain states.
Our Final Thoughts on REM Sleep
REM sleep is still ultimately mysterious despite how much researchers know about it. It offers our best opportunity for studying the underlying function of dreams, especially their connection to our waking consciousness states.
Additionally, REM sleep is thought to be connected with our creativity, with many researchers thinking that our learning from the day is solidified in this particular stage. These researchers believe that dreaming represents the brain testing out much of what it learned throughout the day but doing so in a space that is free from danger and loss.
Ultimately, as long as researchers continue probing the mysterious REM cycle of sleep, eventually they will uncover its origins and purpose. Many researchers even think it is connected to the origins of humanity, so this is definitely an exciting time in our understanding of sleep.
Feature image via The University of Sydney