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What Does Our Brain Do While We Sleep?

Anuya Waghmare Mar 14, 2019
If you thought that our brain also sleeps when we are in deep slumber, think again. Though physically we are relaxed and at ease, there are a lot of things going on in our brain while we are asleep. Read here to know what our brain does while we sleep.

Did You Know?

Over a 24-hour period, our brain can process up to 70,000 thoughts, even when we sleep. A day comprises 86,400 seconds, which means a new thought is processed every 1.2 seconds! So, our brain never really stops working.
Sleep is a restorative function which helps relax and renew yourself. Sleep is essential for our good health and well-being. Hence, all our body processes are shut down so that we can enjoy a good night's sleep.
However, you will be surprised to know that our brain is very active during this time. As it turns out, the activity in the brain during this time is very important for our learning and cognitive abilities.
Dr. Frederick R. Carrick, DC, PhD, President of the American Chiropractic Association Council on Neurology has this to say...
"Sleep is one of the most important functions of the brain. Through it, our bodies recharge and renew for the next day's challenges. Sleep regulates your mood, is related to learning and memory, and is a key factor in your health, weight, and energy level."
So, what really happens in our brain when we are sleeping? We have tried to answer this question for you.

Sleep Helps Recollect Knowledge

According to a study by the University of Chicago, sleep helps the mind learn complex tasks. It helps recover any forgotten knowledge or skills that people thought they failed to remember during the day.
One more study found that people who thought that they had lost a skill and did not remember how to play a particular video game after 12 hours, were able to do so after a night's sleep. Thus, their abilities were restored after sleeping.
Sleeping fortifies knowledge that was lost during the day and protects it from losing it further. Thus, it plays an important role in learning new skills, strengthening them, and stabilizing memories so that these skills are etched in your memory forever.
Scientists believe that this process may also help when learning new languages or developing various tactics while playing games or consolidating.

Effects of Sleep on Memories

A recent study led by researchers at the Beth Israel Deaconess Medical Center (BIDMC) and Boston College offers new breakthroughs in the formation of emotional memories. It suggests that sleep helps in determining and sorting out things that we remember and forget.
According to these discoveries, during sleep, the brain selectively preserves and enhances those aspects of a memory which have a greater emotional value. At the same time, those which the brain considers as less valued or neutral are discarded.
For example, if someone is shown a scene with a damaged building or wrecked car, then the object which has more emotional value will be retained by the brain, as opposed to other things in the scene.
The brain helps restore, restructure, and organize our memories, which may be the reason why people come up with new ideas and different angles to a particular problem after a night's sleep.

Sleep Assists in Remembering the Order of Events

A study headed by Jan Born at the University of Lübeck has confirmed that long-term memories are also formed during sleep. It is clear now that sleep helps us remember the chronological order of particular events in our memories.
This is achieved by replaying the day's events and experiences during the night. Thus, the brain not only helps in fortifying memory, but also establishes the sequence of events in which we recall the memory.

Stages of Sleep and Dreams

There are two stages of sleep:
  1. NREM (non-rapid eye movement)
  2. REM (rapid eye movement).
Many changes occur during the NREM phase, wherein our body muscles relax and many other functions, like brain activity, heart rate, respiration, blood pressure, and temperature of the body slow down as compared to the rate at which they occur when we are awake.
The REM stage is an active stage when each of these processes increase beyond the levels when we are awake. Blood flow to the brain increases, and sexual erections may occur. Eye movement is rapid, as if we are awake and watching a moving object. However, the limb muscles are paralyzed, which prevents us from reacting during this phase.
The REM stage is when most dreams occur and according to researchers, we spend about 2 hours every night dreaming. The dreams may be vague or vivid images where our brain processes and gathers information during this phase. This is where our brain tries to work on information and make connections, which may help gain insights or decipher the meaning of life.
This may be the reason why Russian scientist Dmitri Mendeleev reported to have formulated the periodic table in his sleep, and chemist Friedrich August Kekulé figured out the structure of the benzene ring, after dreaming about a snake that was biting his own tail.
Many things are still unclear about dreams as to why and how they occur, or their significance. However, studies have also demonstrated the harmful effects of sleep deprivation on our health.

Effects of Sleep Deprivation

▶ Research has shown that lack of sleep has detrimental effects on our overall cumulative ability. It affects attentiveness, concentration, thinking ability, and memory.
Sleep is necessary for the proper functioning of our nervous system. Continued sleep deprivation can produce mood swings and hallucinations.
▶ Some scientists also believe that neurons repair themselves and take rest when we sleep. Without sleep, the neurotransmitters and other products of the normal activities in these cells may take a toll and cause malfunctioning of these neurons.
▶ Sleep deprivation poses great risks to the normal well-being of a person. A Harvard study found that women who sleep for less than 7 hours were at a slightly higher risk of heart diseases and diabetes.
▶ According to a study conducted by the National Sleep Foundation, in 2002, anger, dissatisfaction, irritability, crankiness, and many other negative emotions are higher in people who get less sleep. Sleep and mood are regulated by the same brain chemicals.
▶ According to the National Highway Traffic Safety Administration, driver fatigue, which mostly occurs due to sleep deprivation is the main reason behind an estimated 100,000 motor vehicle accidents and 1,500 deaths every year.
▶ Lack of sleep has an effect on our immune system, and people with chronic diseases may suffer from sleep-related disorders, like insomnia, sleep apnea, etc.
Thus, sleep is critical for our well-being and survival. Researchers say that sleep patterns greatly influence our activities. Brain imaging and other techniques have led them to understand many things about sleep and the overall working of the brain. However, we still have a long way to go to attain a thorough understanding of sleep, brain, and its working.