When we sleep, our brain experiences five different stages divided into two major parts. One is non-rapid eye movement (NREM), and the other one is rapid eye movement (REM) sleep (dreams occur in this stage mostly). During an ordinary night, we dream for about 2 hours, broken up by the sleep cycle. In the following, we will explain the stages of sleep and how, when, and why dreams happen.
Stages of Sleep
As mentioned above, our brain experiences five different stages when we go to sleep. The first one is rapid eye movement (REM) sleep, in which the eyes move in various directions rapidly. The other four phases are known as non-REM (NREM) sleep.
We usually enter REM sleep within the first 90 minutes. Since the sleep cycle repeats throughout the night, REM sleep happens several times per night. It accounts for over 50 percent of an infant's and 20 to 25 percent of an adult's sleep cycle. Most dreams happen during REM sleep, and it is thought to play a role in learning, mood, and memory. Here are some facts on REM sleep:
- In this phase, breathing can become irregular and fast.
- During REM sleep, your brain is almost as active as it is when you are awake.
- Drinking alcohol before bed decreases the amount of REM sleep we have.
- Individuals with REM sleep behavior disorder act out their dreams.
- REM sleep can help consolidate memories.
REM Sleep
The first phase of REM typically lasts for 10 minutes, with each phase getting longer progressively. The final stage of REM sleep lasts for up to an hour. During REM sleep, the brain and body go through many changes, including:
- The rapid movement of the eyes
- Increase in heartbeat rate (to near waking levels)
- Irregular and fast breathing
- Changes in body temperature
- Raise in blood pressure
- Increase in oxygen consumption by the brain
- Sexual arousal in both genders
- Twitching of the limbs and face
In most individuals, a state of temporary paralysis is experienced as the brain signals the spinal cord to cease the movement of the legs and arms. This shortage of muscle activity is known as Atonia, and it might be a protective mechanism to avoid injury that may be caused by acting out your dreams.
REM sleep is often related to very vivid dreams due to increased brain activity. Since the brain is still active, the muscles are not immobilized in this stage. It is sometimes called paradoxical sleep.
Non-REM Sleep
Before starting the REM sleep phase, the body goes through all the stages of non-REM sleep. Every stage of NREM lasts for 5-15 minutes.
Stage 1 non-REM sleep: In this stage, we are between being awake and asleep or are in a very light sleep.
Stage 2 non-REM sleep: A slightly deeper sleep characterizes this stage. Heart rate decreases and body temperature drops.
Stages 3 and 4 non-REM sleep: This state of restorative and deep sleep is known as delta sleep or slow-wave sleep. The supply of blood to the muscles increases, the muscles relax, and the body grows and repairs tissue. Energy stores are replenished, and hormones are secreted.
As a person ages, they tend to get less NREM sleep. Those under 30 typically experience 2 hours of restorative sleep per night, while older adults might get just 30 minutes.
Functions
According to the National Sleep Foundation, REM sleep is believed to affect learning, mood, and memory positively. It is also thought to contribute to brain improvement in infants. However, a shortage of REM sleep might have an adverse effect on emotional and physical health.
- Learning and Memory
Research recommends that when individuals are unable to enter REM sleep, they have difficulty remembering what they were taught before sleeping. According to research carried out on rats, just four days of REM sleep deprivation have a considerable impact on cell proliferation in the part of the brain that is related to long-term memory. A combination of both non-REM sleep and REM is likely necessary for both memory and learning.
- Central Nervous System (CNS) Improvement
REM sleep might be significant for brain improvement in infants. Some studies indicate that this sleep stage is responsible for the neural stimulation essential to develop mature neural connections. These findings might help explain why infants need higher levels of REM sleep each night. The duration of REM sleep falling as people get older.
Consequences of a Lack of REM Sleep
A lack of REM sleep can result in:
Reduced coping skills: Research shows that animals deprived of REM sleep show abnormalities in defensive responses in threatening situations and coping mechanisms.
Overweight: According to a study conducted in the University of Pittsburgh, short sleep times and reduced REM sleep were related to excess weight in children and adolescents.
Migraines: The less REM sleep we have, the more migraines we experience.
Ways to Improve REM Sleep
There are many ways to enhance both NREM and REM sleep to increase the benefits of a good night's sleep. The following tips might be helpful in having a better REM sleep:
- Establish a Bedtime Habit
By having a bedtime routine every night, the body and mind will be prepared for rest. A regular bedtime routine usually plays a vital role in maximizing the duration of time asleep. As a result, the number of REM sleep phases will rise.
- Reduce Night Time Waking
Loud noises, bright lights, and warm temperatures can interrupt sleep. For better sleeping conditions, switch off cell phones and all sources of sound, and eradicate light sources from the bedroom. It's better to sleep in temperatures between 60 and 67 degrees Fahrenheit.
- Sleep Enough
A healthy adult requires 7-9 hours of night sleep. Sleeping less than this decreases the number of REM sleep phases.
- Avoid Alcohol Before Bedtime
Moderate to high levels of alcohol intake before bed can decrease the duration of REM sleep phases. Also, any amount of it delays entering the first REM phase. Therefore, it is advised to avoid alcohol consumption before bed.
- Address Medical Conditions
Certain medical conditions, such as sleep apnea, can have effects on sleep quality and REM sleep.
What Are Dreams?
Dreams are images and stories our mind creates while we sleep. They can change our feeling into being happy, scared, or sad. Although dreams can happen anytime during sleep, most vivid ones occur during deep, REM (rapid eye movement) sleep, when the brain is in the highest level of activity. Some experts claim that we dream at least four to six times per night.
Why Do We Dream?
There are various theories about why we dream, but no one knows for sure. Some researchers say dreams have no meaning or purpose, and they are nonsensical activities of the sleeping brain. However, others believe that dreams are necessary for mental, physical health, and emotional.
Studies have depicted the importance of dreams in our well-being and health. Researchers have discovered that those participants who were not allowed to dream experienced had:
- Increased tension
- Depression
- Anxiety
- Difficulty concentrating
- Tendency to hallucinate
- Weight gain
- Lack of coordination
Many experts say that dreams:
- Help solve problems in our lives
- Process emotions
- Incorporate memories
If we go to bed with bad thoughts, we may wake up with better feelings, situation, or a solution. Sigmund Freud believed that dreams are a window into our subconscious. He assumed that they reveal a person's:
- Unconscious desires
- Motivations
- Thoughts
Freud thought dreams are a way for people to satisfy desires and urges that were unacceptable to society. Perhaps some dreams may help our brain process our thoughts and the events of the day. Others might be the result of regular brain activity and mean little if anything. Researchers are trying to find out exactly why we dream.
What Do Dreams Mean?
Just as there are different opinions about why we dream, there are also different views as to what dreams mean. Some researchers say dreams have no connection to our real thoughts or emotions. They are just strange stories that are not relevant to normal life.
However, others argue that our dreams might reflect our underlying thoughts and feelings, our deepest desires, fears, and concerns, especially recurring dreams. By interpreting our dreams, we might be able to gain insight into ourselves and our lives. Many individuals say they have come up with their best ideas while dreaming. Therefore, we can conclude that dreams might be a conduit of creativity.
People often report having similar dreams; they are being chased, appear in public naked, or fall off a cliff. These types of dreams are likely caused by hidden anxiety or stress. While the dreams might be similar, experts say the meaning behind the dream is unique to each person.
Thus, many researchers believe that we should not trust in books or "dream dictionaries," which give an exact meaning for a specific dream symbol or image. The particular reason for our dream is unique to us. Although scientists can't say for sure the meaning of dreams and why we dream, many individuals find meaning in their dreams.
Nightmares
Bad dreams (nightmares) are common in adults and children. Nightmares are usually caused by:
- Stress, conflict, and fear
- Emotional problems
- Trauma
- Illness
- Medication or drug use
If we have a particular continuous nightmare, our subconscious might be trying to tell us something. Therefore, it's better to listen to it. If we can't find out why we have bad dreams, and we continue to have them, we must talk to a mental healthcare provider. They might be able to help us discover what is exactly causing our nightmares and provide tips to figure it out. Remember that no matter how scary a nightmare is, it is not real and most likely will not occur to us in real life.
Lucid Dreams
Have you ever had a dream where you knew you were dreaming during your dream? This is called a lucid dream. Studies have shown that lucid dreaming is accompanied by increased activation of parts of the brain that are commonly suppressed during sleep. Lucid dreaming shows a brain state between REM sleep and being awake.
Some lucid dreamers can influence the direction of their dream and change the story. While this might be an excellent tactic to take, especially during a nightmare, some dream experts believe that it is better to let our dreams happen naturally.
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