The Science Behind Sleep

In this article, Emme explains what happens while we are sleeping and why. She discusses several sleep symptoms and how the brain causes these strange events.  

What happens while you are sleeping

By: Emme Randall

Sleeping is very important to health, both physical and mental. Our sleep can affect our mood, and even our day. However, while sleeping, people may have odd or startling experiences. These experiences can reveal much about how the brain and body function, as well as help us learn how to get better, more enjoyable sleep. 

A sleeper. Image credit to News Medical

Dreams are individual to a person. Someone may dream in vivid colors, or in black and white. It may be very realistic, or very random and confusing. Eric Sunni, Staff Writer at Sleep Foundation, states that those who are blind tend to dream more in “sound, taste, and smell.”  There are also lucid dreams, in which the sleeper is aware that they are dreaming and, in some cases, are also able to control those dreams. The purpose behind dreams is still much debated, though many discoveries have been made. 

A common sleep sensation is the feeling of falling or floating when the dreamer is going to sleep. Cleveland Clinic estimates that “70% of the population may experience” this as well. This twitch or jerk feeling is often called hypnic myoclonus or sleep myoclonus. Dr. Vipul Gupta  of Wockhardt Hospitals notes that hypnic myoclonus may also come with “a sensory flash, feeling of falling and a visual dream.”  This sensation commonly happens during the first stages of light sleep. This may be because there is still a sense of wakefulness, but the muscles are not moving. Because of this, the brain sends out a signal to move the muscles, resulting in the hypnic myoclonus. However, this is just one of several theories. Stress, stimulants, sleep deprivation, and caffeine can all affect the sleep cycle. Any disruption to the sleep cycle causes an increase in the chance of experiencing the falling sensation. This sensation is not dangerous in normal circumstances. However, if hypnic myoclonus is happening frequently during sleep, Dr. Mehra of Cleveland Clinic states that “myoclonus can be a symptom of more complex sleep disorders.” If this is the case, it is important to reach out to a doctor. 

Caffeine. Image Credit Recovery Direct 
Restless eyes. Image credit  Zleepy 

Many times, the sleeper will not recall the hypnic myoclonus, for the same reason many struggle to remember their dreams. Norepinephrine is the chemical in the brain that helps retain information and memories. While sleeping, the levels of norepinephrine are at their lowest in the brain. This causes many to forget what they dreamed about. It may also result in not being able to recall experiencing the falling sensation. If a sleeper does not wake up during the dream, Healthline notes that they ”won’t be able to remember it.” Generally, a person may have three to six dreams a night. Many dreams happen during the Rapid Eye Movement, or REM, stage of sleep. Dreams may seem to take more time than they do. Once again, there are several theories, but no exact facts about why this happens. Sleep Foundation explains two theories. First, the “brain activity might be slower in REM sleep compared with waking life,” the Sleep Foundation states because “the brain is at a lower temperature.” The other theory is that, since muscles are paralyzed at this time, the brain recognizes that doing activities should be more challenging and take longer: “The brain simulates physical effort by assigning more time to actions it considers tiring”. 

Although much remains unknown about sleep, various theories and recent discoveries have shed light on its nature and impact. Future breakthroughs may alter our understanding of dreams and the sensory experiences of sleepers, as we continue to unravel the mysteries of the mind and body.