REM sleep is a vital part of the sleep process. Research continues into the exact nature of sleep, the physiological and psychological need for sleep and more. One thing is certain: people need to achieve rapid eye movement sleep in order to enjoy the full benefits of their sleep cycle.
REM Sleep: The What
Identified in the early 1950s, REM sleep refers to rapid eye movement or the physiological response of the body when it enters this particular stage of sleep. Dreaming is most often associated with REM sleep, due to the vivid nature of the dreams in this stage of sleep. While studies continue into the nature of sleep and into why people need it, experts agree that REM sleep is important to overall sleep health, but the why of it is the content of many theories on sleep.
REM Theories of Sleep
Several theories suggest why REM sleep is important to day-to-day activities. Theories of sleep regarding REM include:
- Memory consolidation - Some experts believe that it is during REM that the mind processes short term memories into long-term storage, sorting out what is important from what is incidental.
- Neural Stimulation - REM sleep drops off as a person ages, leading some experts to believe that the neural stimulation during infancy and childhood is vital to the developing mind, but not as important to the adult mind.
- Rebooting Neurons - Another theory of REM is that it is a time for the monoamine receptors to shut down and reboot. This increases the brain's sensitivity to neurotransmitters. Repeated interruptions of REM sleep can lead to depression, crankiness and lack of cognitive function.
- Sentinel Hypothesis - In 1966, a scientist observing many different animal species suggests that REM sleep occurs when the body awakens enough to scan the area for predators before falling back into a deeper state of sleep. This theory does not take into account the body's paralysis during REM.
Multiple theories exist with regard to REM and the various sleep stages, but the body's need for sleep is both physiological and psychological. Theorists speculate that through understanding sleep, one may understand the brain better and vice-versa.
Physiological Effects in REM
During REM, the body goes through a type of sleep paralysis. Muscles go rigid, preventing movement. Some speculate that this is due to the vivid nature of the dreaming that occurs, preventing the active signals in the brain from being sent to the limbs, reducing flailing and possible injury.
Hormones and neurotransmitters such as acetylcholine affect the peripheral nervous system regulating the sleeping and waking cycle as well as REM sleep. Deprivation of some neurotransmitters can reduce time spent in REM or the frequency of it thereby reducing the amount of rest the body gets while sleeping.
Sleep apnea patients often spend little to no time in REM, which may contribute to their severe daytime fatigue and depressed immune systems. CPAP therapy can help sleep apnea patients avoid the choking, gasping that leads to waking frequently throughout the night. The return of REM sleep can be very relaxing to the mind and the body. Sleep doctors can monitor the amount of time spent in REM through a sleep study. The average adult experiences the REM stage four to seven times a night in a typical seven-hour sleep period.
Dreaming occurs during REM sleep. While experts speculate that dreaming may occur during the other stages of sleep, the level of brain activity and the vivid recall of dreamers is heightened during REM. Dream studies examine the meaning behind dreams and there are more theories about the dreaming state than there are about the REM sleep that leads to them. Most experts, however, agree that REM is positive sleep and vital to the overall mental and physical well-being of individuals.
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