Scientists agree that sleep is essential for health, and while stages 1 to 4 and REM sleep are important, deep sleep is the most essential of all to feeling rested and staying healthy. While a person needs all stages of sleep, deep sleep is especially important for brain health and functioning. Deep sleep helps the brain create and store new memories and improves its ability to collect and remember information. The hallmark of REM sleep is in its name rapid eye movement.
In this fourth stage of sleep, brain activity accelerates so much that you seem to be awake on brain scans. Your heart rate, blood pressure, and breathing also recover. As your eyes move back and forth, your muscles and body are paralyzed, Drerup says. During the deep stages of NREM sleep, the body repairs and regrows tissue, develops bones and muscles, and strengthens the immune system.
It's about restful sleep, physical recovery and strengthening the immune system during this crucial stage. Although no one knows exactly why most living things sleep, medical research suggests that time spent sleeping is essential to performing essential maintenance and repair within the body. Sleep spindles are periodic bursts of activity at approximately 10—12 Hz that usually last 1 to 2 seconds and arise as a result of interactions between thalamic and cortical neurons. Deep sleep is different from REM sleep in that deep sleep is geared towards physical maintenance, while REM sleep is responsible for mental maintenance.
Now that you understand the importance of sleep cycles, it's essential to make sure you include as many as possible in your nighttime sleep. For example, benzodiazepines decrease the amount of time a person spends in the deep sleep and REM sleep stages. Even though brain activity decreases, there is evidence that deep sleep contributes to insightful thinking, creativity, and memory. Not getting enough deep sleep and REM sleep can explain some of the profound consequences of insufficient sleep on thinking, emotions, and physical health.
REM sleep is known for its most vivid dreams, which is explained by the significant increase in brain activity. In stage III sleep, which represents moderate to deep sleep, the number of spindles decreases, while the amplitude of low-frequency waves increases even more. Physiological changes in a male volunteer during the various sleep states in a typical 8-hour sleep period (A). In some cases, poor quality sleep may be the result of aging, while in others, it may be due to a sleep disorder.
A new study also found evidence that getting more sleep on weekends may lessen some effects of sleep deprivation, but more research is needed. Instead, throughout the night, total sleep is made up of several rounds of the sleep cycle, which is made up of four individual stages. However, even a physically perfect human body would be of no use if your brain has gone crazy from a lack of REM sleep.