REM sleep is more commonly defined as the sleeping stage where people dream. However, Rapid Eye Movement sleep is also known as active sleep, where the brain goes through multiple processes.
During this stage, your eyes move rapidly, but your brain doesn't receive any signals of visual activity. Hence the name rapid eye movement. Non-REM sleep stage comes before REM sleep, and the latter lasts for a shorter time period.
What Happens During REM Sleep?
As the name is derived, REM sleep consists of your eyes moving fast while closed, your heartbeat increasing, and your breathing abnormal. Brain activity is the highest during this stage of sleep as compared to other stages.
Since this is active sleep, your body goes through the same processes while you're awake, but you are unable to feel anything due to a loss in muscle tone. Some researchers suggest that this is a preventive measure against the body causing harm to itself by acting out any activity during sleep.
Humans don't just experience REM sleep but is also found in animals, including mammals, reptiles, and even some birds. Rapid eye movement differs in every creature. Some birds only lose muscle activity in certain areas of their bodies. Owls can't move their eyes during REM sleep because they are physically unable to.
The Difference Between non-REM and REM Sleep
REM sleep is highlighted as one of the most interesting sleeping stages. During non-REM sleep, which comes before REM sleep, brain activity is much slower, the eyes don't move, and your muscles can move. Let's go through some points which make REM sleep unique as compared to non-REM sleep:
Brain functioning is the same as when you're awake vs. complete shut down of the brain in non-REM sleep.
Abnormal breathing pattern in REM sleep vs. stable and slow breathing in non-REM sleep.
Total lack of muscle strength in REM sleep vs. some muscle strength during non-REM sleep.
Increased heartbeat in REM sleep vs. slowed down heartbeat during non-REM sleep.
Easier to wake up from REM sleep as compared to non-REM sleep.
When Does REM Sleep Begin?
The sleep cycle has a total of 4 stages. REM sleep is the last stage. The first REM sleep cycle takes 60 to 90 minutes to begin. While sleeping, you'll go over all stages repeatedly, and the entire cycle lasts for 90 to 120 minutes. The duration of rapid eye movement sleep increases through each cycle.
Here are the 4 stages of sleep:
Stage 1: This can be defined as light sleep, as your body is slowly drifting to sleep. You have some muscle strength as the brain activity slows down. Alpha brain waves are replaced by LAMF (low-amplitude mixed-frequency).
Stage 2: Also a part of light sleep, during this stage, the body is slowly transitioning to deep sleep. Heartbeat and body temperature start decreasing.
Stage 3: Delta waves of the brain are at their slowest during this deep sleep stage. It is difficult to wake up, and if you do, you'll feel sleep inertia. Your brain will be confused, and your physical movement will be limited. This is the healing time for the body as it repairs, boosts, and restores vitality.
Stage 4: REM sleep is the last stage of the sleep cycle. Brain activity is the highest during this point in the cycle. You lose control of your muscles, but your eyes move rapidly, your heartbeat increases, and your breathing becomes irregular.
Why is REM Sleep Important?
Even though all stages of the sleep cycle are important, REM sleep focuses on brain development and repairing the body. Here is why REM sleep is important for the body:
Most of your dreams occur during REM sleep. The dreams during this stage are said to be more vivid than those in the stages of non-REM sleep.
The Amygdala, the part of the brain that processes emotional functions, is activated during REM sleep. This is also the reason dreams during this stage are more vivid. The brain goes through emotional processing in REM sleep.
The brain processes new motor skills that you may have learned during the day. It then chooses to store some and delete others. Memory consolidation is a part of REM sleep and also the transitioning stage.
Research says that REM sleep is associated with increased brain development since infants have longer REM sleep as compared to adults.
With the central nervous system activated during REM sleep, our body gets prepared to wake up. REM sleep begins during the later part of the night; hence it prepares us to wake up easily.
How Much REM Sleep is Needed?
Infants and children require at least 8 hours of REM sleep since their brains are undergoing development. For adults, the average REM sleep requirement is 2 hours during the night.
REM sleep varies according to the energy levels of an individual as well as your body's requirements. If your body needs more REM sleep, you'll end up in this stage longer than the average time.
Studies conducted on humans and rats showed an increase in REM sleep when new things were learned.
What Happens If You Don't Get Enough REM Sleep?
Studies show that a lack of REM sleep affects memory. Since the brain goes through repairing and healing during this stage, little or no REM sleep stops the formation of new brain cells.
Sleep deprivation is also bad for your health since you are unable to concentrate on work/studies. Moreover, you feel tired throughout the day, and your memory also suffers.
REM sleep and overall sleep are important for your health. If you face any sort of sleep disturbances, then you can contact American-board certified and trained sleep specialists for a consultation on SleepRx.
An overnight test can determine your sleep activity and check your sleep cycle stages. Sensors attached to the body can read heart, brain, and lung activities while you sleep. Doctors will thus be able to understand and treat your REM sleep behavior disorder, if any.
If you don't want to step out of your home, then you can also opt to have this test conducted from the comfort of your home. Your test will be videotaped, and the doctors can monitor all activities from the attached sensors.