How Sleep Works: Understanding the Science Of Sleep

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Table of Contents

Importance Of Sleep

The science of sleep is a fascinating subject. Follow it through our comprehensive guide to the stages of sleep and dreaming, including REM, to better understand what happens while you’re sleeping.

When you are asleep, your body rests, but your brain remains busy. For instance, during Rapid Eye Movement (REM) sleep that begins about 70 to 100 minutes into sleep, your brain becomes more active than when awake. This is similar to the period between wakefulness and being fully rested when you are in a dream state known as rapid eye movement or REM for short. But how does this happen? What do you do when you are dreaming?

The dream state is usually characterised by stereotyped, often bizarre images that can be remembered after awakening. In addition, dreams typically involve a sense of familiarity, as if they have been experienced before. Even though you may never have seen the dream content before. Finally, the emotions associated with dreams are generally robust, such as fear or happiness.

REM sleep is associated with dreaming because most dreams occur during this stage. REM sleep occupies up to 25 per cent of total sleep in adults. And its duration increases from about 10 minutes at the beginning of rest to 30 minutes at the end of sleep. REM sleep periods become longer and more frequent as the night progresses.

But why do we dream? The answer is not yet clear. There are many theories, but currently, no single idea explains all aspects of dreaming. Some scientists have proposed that dreams carry a function. Such as consolidating memory or integrating recent emotional experiences into the psyche. Other researchers may use REM sleep to remove specific undesirable characteristics from the brain because there is an increase in activity occurring during this stage.

Although scientists do not know for sure why we dream, there have been several theories put forth to explain what happens while we sleep and dream.

The Somatic-Activation Theory

The Somatic-Activation Theory suggests that dreams help us understand and confront our feelings and desires by presenting them symbolically as part of a storyline. For example, if someone were to grab your hand, you would feel quite threatened. However, in a dream, you may have a vision in which someone holds your hand, and instead of feeling frightened, you feel excited. This would allow you to confront that fear and understand it better.

The Cognitive-Processing Theory

The Cognitive-Processing Theory suggests that dreams help us sort through the day’s events and consolidate memories. The theory is actually based on the idea that more activity in the brain’s frontal lobes during REM sleep is responsible for cognitive processing. This increased activity allows the brain to process information from the previous day and store it in memory.

The Cognitive-Processing Theory

The Psychoanalytic Theory suggests that dreams are a way for people to work through their unconscious thoughts and desires. Freud believed that the content of dreams reflected a person’s secret wishes and desires that are being repressed by the conscious mind. He also thought that dreams are similar to symptoms of mental illness because they both have meaning and reveal things about a person’s innermost thoughts.

For example, if someone is sad or depressed, there may be no outward signs of this in their behaviour. However, in a dream, this person could appear low in quite an overt fashion, which would allow people to see what was going on in their lives. This theory suggests that dreams serve as a safety valve for unconscious desires and impulses that are undesirable, suppressed, or otherwise unacceptable when awake. 

For example, many people wish to commit suicide but rarely do so while awake because it is socially unacceptable. However, in dreams, this desire can sometimes surface because sleep provides a setting where these thoughts and desires can be expressed without fear of social or personal repercussions.

The Activation-Synthesis Theory

The Activation-Synthesis Theory suggests that dreams result from the brain trying to make sense of random signals generated during REM sleep. This theory is stated on the fact that there is more activity in the brain’s limbic system during REM sleep, which is responsible for emotions, than during other stages of sleep. The theory suggests that this increased activity causes the brain to generate random images and sensations interpreted as dreams.

And, it should be kept in mind that there is currently no scientific evidence to support any of these theories.

How important is sleep hygiene?

Sleep hygiene is necessary for everyone, from newborns to adults. Sleep hygiene habits encourage restful sleep and daytime alertness. Good sleep hygiene techniques might help you avoid developing sleep difficulties or disorders.

How do you maintain sleep?

It is pretty impossible to get a good night’s sleep if you don’t set up the proper environment. First, make sure your room has no distractions, and be sure that it’s cool enough for sleeping in order not to stimulate yourself. Limit daytime naps since they can make us less tired at bedtime by providing extra endorphins, released during our waking hours when we’re on alert. But need them while trying restful slumber. Finally, include physical activity in your daily routine. Hence, it’s easier and healthier throughout each day and it will help avoid those worries before bedtime too.

Last but not least, develop a bedtime routine and stick to it every night

  • Have a light dinner.
  • Avoid caffeine, alcohol, cigarettes, and eating sugary foods before bed.
  • Do something calming like reading or stretching for about 30 minutes before sleep.

That should help you fall asleep easier and enjoy more restorative slumbers.

What Is Cannabidiol (CBD)?

CBD is a type of chemical found in hemp that has been increasingly used in the United States. While CBD has been shown to have a wide range of health benefits, scientists are still unsure about its efficacy in most cases. As a result, CBD is sometimes marketed as a pill or oil with little THC and high quantities of CBD.

What Are the Effects of Taking CBD?

CBD gives a soothing effect on the nervous system and alters mood because it affects serotonin production. Outcomes vary among people depending upon what product type or dose they take. Still, no specific side effects are known at this time for most CBD consumers who use medication responsibly in their day-toothbrush routine. With few other substances mixed into food during meal times – which would be considered an ” evening” activity depending on how long you’ve been working hard all day!

What is REM rebound?

REM rebound is an increase in REM sleep that can happen after someone has been woken up during this stage of the sleep cycle. The amount of time spent in REM sleep will typically be longer if a person wakes up during this stage.

REM behaviour disorder (RBD) and CBD

REM behaviour disorder (RBD) is a condition where people act out their dreams physically, sometimes injuring themselves or their bed partners. RBD occurs when there is a problem with the brain’s ability to switch off muscle impulses during REM sleep. RBD is seen in about 8% of adults over 50. CBD seems to have a calming effect on individuals who suffer from this disorder which can decrease the chance of violent behaviour while still allowing them to experience dreams that are important aspects of their regular sleep cycles.

What Health Conditions Can CBD Help?

CBD is an effective treatment option for epilepsy, with additional research suggesting it may also help treat schizophrenia and substance use disorders. So far, there’s insufficient evidence on whether CBD works in other health conditions. However, preliminary studies suggest that cannabinoids can ease sleep problems such as insomnia. REM behaviour disorder, and excessive daytime tiredness. Even hints that say this plant-based supplement could be beneficial when used by patients suffering from anxiety.

How Can CBD Help With Sleep Disorders?

Research on the effects CBD has on sleep disorders is still preliminary. Some people who use it for chronic pain report sleeping better, but this may be because of relief from their symptoms and not directly due to a change in how long they can stay asleep or waking up less often during nighttime hours. 

As well as not feeling overly tired after waking up from such sessions like one tends to do when taking an opiate drug without any additional assistance with getting out of bed (or at least moving about).

Anxiety and CBD

Whether acute or chronic, anxiety can contribute to bad sleep quality, insufficient sleep, and sleep disorders. Early research indicates that CBD may treat anxiety-related conditions because it relaxes the nervous system. According to one study, almost 80% of those who took CBD to relieve their anxiety had reduced anxiety levels after a month. In addition, sleep improved in more than 65% of patients; however, fluctuations were apparent in about 35%.

Insomnia and CBD

The human brain’s endocannabinoid system plays an essential role in regulating sleep patterns. If this network is damaged, it can lead to a wide range of disorders, including insomnia which causes difficulty sleeping or staying asleep at night. People who suffer from these issues often experience morning wakefulness and abnormal moods due to a lack of restful slumber.

What are the stages of sleep?

The stages of sleep are the five different phases that a person goes through during sleep. Four distinct brain wave patterns can be seen on an EEG test during these five stages of sleep. 

They include the following:

1. Stage one is light sleep, where you drift in and out of awareness. During this stage, the eyes move very slowly, muscle activity slows down, and people often feel disoriented when they wake up from this stage of sleep because it’s so light.

2. Stages 2 & 3 are together known as non-REM or NREM (for “non rapid movement”) sleep because the body is in a state of deep relaxation. This is when most people sleep the majority of their sleep time.

3. Stage 4 is REM sleep, which is named after the rapid movement of the eyes during this stage. This is when dreaming occurs. 

4. Stage 5, also known as REM rebound, happens when someone has been woken up during REM sleep and then falls back asleep. They will often experience more intense dreams during this second bout of REM sleep.

What is the importance of sleep?

Sleep is an active state when the body regenerates and repairs. A lack of sleep leads to fatigue, daytime sleepiness, mood swings, irritability, and anxiety. It can also lead to weight gain or loss. This is because, during the early stages of sleep, the metabolism slows down, causing blood sugar levels to drop. And then, in turn, cause sugar cravings like eating candy bars in one sitting, which many people do when they’re tired and run down.

Why do we need sleep?

The purpose of sleep has long been a mystery, but scientists now know that sleep is crucial for overall health. The body repairs and regenerates tissues during sleep cleanses the brain of toxins and strengthens the immune system. Sleep also helps us process memories and learn new things. For children, sleep is essential for growth and development.

What are hypnopompic hallucinations?

Hypnopompic hallucinations are sensory experiences that happen while transitioning from sleeping to wakefulness. These hallucinations can take many forms, including simple sounds like breathing or music playing in another room. Something was walking into the room ( it’s worth noting that patients with narcolepsy tend to get this type of hallucination more often ), sexual thoughts, people talking, having sex, and out-of-body experiences. All of these, though, do have a nature of being surreal in some way, shape, or form.

How to become a light sleeper?

Some natural remedies could help someone become a light sleeper. The first would be to keep their bedroom as cool as possible without it being too cold. This is because the body’s core temperature drops when a person falls asleep, and if it gets too warm, it will make falling asleep difficult. Second, make sure there aren’t any lights on in the bedroom because the brain registers them as disturbances. 

Third, avoid screens like televisions or phones which emit blue light, which suppress melatonin (the sleep hormone), and instead read a book or do some deep breathing to relax. 

This should signal to the brain that it’s time for bed and ease into a restful slumber. Fourth, do not exercise before going to bed; this will help get rid of excess energy before climbing into bed. Fifth, stay away from caffeine, particularly within four hours of bedtime, because it can keep the brain active. Finally, stay off alcohol for at least three hours before trying to sleep. 

How to know if someone with insomnia is ready for REM rebound?

There’s no way to tell if someone suffering from chronic insomnia awakening during REM sleep is ready for it regarding their particular situation. However, with most people suffering from insomnia, one of the most effective ways that they can treat their problem is using CBT or cognitive behavioural therapy. 

Which helps them improve their negative thought patterns and learn new coping skills that are more adaptive, allowing them to have a better quality of sleep. Of course, it’s not a perfect solution for everyone, but it has helped many people to get their sleeping schedules back on track.

REM rebound and how it can help those with chronic insomnia?

REM rebound can be an effective way for people with chronic insomnia to get their sleeping schedule back on track. REM rebound occurs when someone has been woken up during REM sleep and then falls back asleep.

They will often experience more intense dreams during this second bout of REM sleep. This increased dream activity can help to “reset” the brain and improve sleep quality overall. Although it’s not the best solution, it has helped many people control their sleeping schedules.

Do you burn calories when you sleep?

Every individual burns a distinct quantity of calories while resting, depending on their basal metabolic rate (BMR). We burn around 50 calories every hour when we sleep as an approximate number. Every person burns additional calories while sleeping based on their own BMR.

What are sleep spindles?

The thalamic reticular nucleus and other thalamic nuclei generate bursts of oscillatory neural activity. During stage 2, NREM sleeps in a frequency range of 11 to 16 Hz. With a duration of 0.5 seconds or more, they are known as sleep spindles.

What is the function of sleep spindles?

Non-rapid eye movement (NREM) sleep has main spindles, an electroencephalographic (EEG) sign and is thought to mediate many sleep-related processes, including memory consolidation and cortical growth.

What are the side effects of sleeping too much?

In most cases, sleeping too much will have no adverse side effects on your overall health. However, there can be times when it is necessary to rest beyond the standard 8 hours, such as recovering from illness or staying up late for work or school commitments.

How long does it take to fall asleep?

It typically takes 10-20 minutes for an individual to fall asleep once they climb into bed. Usually, this amount of time includes how long it takes someone to change positions and their mind to fully relax to feel safe in closing their eyes and drifting off. 

How does caffeine affect your body?

Caffeine increases alertness and provides energy, particularly to those fatigued because it increases adrenaline production, which forces active muscles to work harder than they would on their own. It also prevents adenosine, a neurotransmitter that signals drowsiness, from binding to receptors in the brain. As a result, caffeine can effectively block the harmful effects of adenosine and keep you feeling more awake.


Ameer is the content director of Sleepingmentor, which means he not only reviews new mattresses, bedsheets, pillows, and mattress toppers every week, but also curates all the comparisons, best of pages, reviews pages, and vs pages on the site. He takes a straightforward, honest approach to his reviews. He covers sleep science by researching a lot on Google and finding meaningful content which entertains his users.

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