The Science Behind Sleep and Dreams

Astronaut Abby_The Science Behind Sleep and Dreams_Header ImageHave you ever wondered if our dreams really mean something, why we have them, or if they are beneficial to us in some way? For years, scientists have been asking the same questions. While dreaming is something we do every day, we still don’t know a lot about it.

We often take sleep and dreams for granted. As I wrote in Chapter 7, “Striking a Balance,” of my book, Dream Big!: How to Reach for Your Stars, “Sleep is truly one of the most important basic needs that you have, and it’s one that’s often overlooked.” Delving into the science behind sleep and dreams teaches us a lot about how our brains work. By learning more, we can make the most out of our (literal) dreams and use them to help us reach our (figurative) dreams. Keep reading to learn more about what science does and doesn’t know about sleep and dreams!

Astronaut Abby_The Science Behind Sleep and Dreams_Sleeping Cat_ImageThe Science Behind Sleep and Dreams: What We DO Know

Sleep and dreams have puzzled scientists for many years. Why do we need to sleep? What is the purpose of dreaming? Answering these questions helps us to understand our basic human needs, so that we can then turn around and optimize them. While research is still being conducted, scientists have already been able to answer many of the most head-scratching questions!

What Causes Sleep?

In order to understand our sleep cycle, we first need to take into consideration the rising and setting of the Sun! When the Sun goes down and natural light disappears, our bodies begin to produce melatonin, a hormone that helps us fall asleep. In contrast, when the Sun rises and natural light increases, our bodies produce more cortisol, which helps boost and balance our energy levels.

Together, this pattern of the rising and setting Sun helps us maintain our own sleep cycle, or our circadian rhythm. Our circadian rhythm is our 24-hour internal clock, and it regulates when we wake up, how tired we get throughout the day, and when we go to sleep. Sometimes, it can get thrown off, and you may find yourself more tired during the day and wide awake at night. This is also a recurring problem for researchers in Antarctica, who experience 24 hours of sunlight during the summer and suffer from something called ‘polar insomnia’!

When we do sleep, we go through four different stages: Stage 1 NREM, Stage 2 NREM, Stage 3 NREM, and Stage 4 REM. The first two are characterized by how soundly we sleep; Stage 1 is light sleep and Stage 2 is deep sleep. Stage 3 is when your body is at its most relaxed, with the lowest breathing, brain activity, and heart rates. These low activity levels contribute to how refreshed and energetic we feel when we wake up. Finally, the last and perhaps most important stage is REM. This is when your breathing, heart rate, and brain activity begin to pick back up. This is also the period when dreaming occurs!

What Causes Dreams?

In REM sleep, it’s believed that we experience our most vivid dreams. Studies have found that dreaming is controlled by forebrain mechanisms, which influence our speech, abstract thought, and pleasure, and the REM stage of sleep is controlled by the brainstem, which helps regulate our heartbeat and breathing. In a chain of reactions, the brainstem can stimulate the forebrain and cause dreams to occur.

Astronaut Abby_The Science Behind Sleep and Dreams_Parts of Brain_ImageImage credit: Cancer Research UK / Wikimedia Commons

Scientists have also found that as we dream, the amygdala, the part of the brain that deals with emotion, is more active than it is while we are awake. As we will see later on, this may be key to understanding the meaning of our dreams!

The Benefits of Sleep

One more thing that scientists DO know about sleep is how it benefits our body. Sleeping comes with numerous benefits! It’s an opportunity for our mind and body to recharge, and the time where our bodies regulate our metabolism, blood pressure, and brain function. It also helps us store memories and manage the digestion process. In fact, while we sleep, a molecule called adenosine, which influences the digestion process, is broken down. Getting rid of this adenosine makes us feel more energized in the morning, so we won’t be so quick to turn to caffeine and other unhealthy foods!

If you want to reap all these benefits, it’s important to get the right amount of sleep and develop the right habits! Learn more in my blog post “THE GOLDEN AMOUNT OF SLEEP”.

Astronaut Abby_The Science Behind Sleep and Dreams_Moon with Ladder_ImageThe Science Behind Sleep and Dreams: What We DON’T Know

One of my favorite things about science is that there is always more to explore! This holds true for the science behind sleep and dreams. We don’t know everything yet, and that opens up room for lots of possibilities. Who knows? Maybe one day you’ll be the one to answer these questions!

Why Do We Dream?

While we have a good idea of what causes dreams, we still aren’t sure why exactly they occur in the first place. However, there are numerous current theories. Some of the most popular say that dreams may…

  1. be a way of dealing with emotions
  2. prepare you to deal with threats to your safety
  3. act as an outlet for your creative energy
  4. help store memories and keep organized

Other theories suggest that dreams could be our brain’s way of responding to external stimuli while we sleep, or how we declutter our mind and refresh for the next day. All of these theories need to take into account the different kinds of dreams, including nightmares and recurring dreams. This means that there may not be one exact reason as to why we dream; the true meaning could be any one of these theories, or all of them combined!

Is Dreaming Good For You?

Are there any healthy benefits of dreaming? Many researchers say there could be! Studies have found that people who spend more time in REM sleep, where dreaming occurs, have less fear the next day. While scientists aren’t entirely sure why this is, they believe it has to do with a hormone called norepinephrine. Norepinephrine is associated with stress, controlling how the amygdala responds to fear. During REM sleep, this hormone is less active, meaning the amygdala is less likely to have a stressful reaction.

Another proposed benefit is better facial recognition! A study by Matthew Walker, director of the Sleep and Neuroimaging Lab at the University of California, Berkeley, found that when participants reached REM sleep during a nap, they were better able to judge facial expressions than those who didn’t. In particular, they could best identify positive emotions, leading Walker to the conclusion that when we are well-rested, we are more intune with positive emotions, as opposed to negative ones.

Do Dreams Mean Anything?

Have you ever woken up from a crazy dream and wondered, “where did that come from?” For years, scientists have thought the same thing! Why, when we go to sleep at night, do we imagine ourselves as superheroes? As Olympic athletes? We can go on such exciting adventures when we sleep, but what do they mean?

Scientists have come up with a couple different theories. Sigmund Freud, one of the most influential figures in psychology, says dreams give us insight into our deeper selves. In his 1899 book, The Interpretation of Dreams, he explains that dreams are our brains’ attempt to resolve a conflict. To do so, our brains mask the conflict, making it appear in our dreams as something different, sort of like a hidden message. Then, while we try to uncover this message, we end up learning a lot about ourselves along the way.

Another theory takes this idea of our dreams being connected to emotions and spins it a different way. This model, called the AMPHAC/AND Neurocognitive Model Of Disturbed Dreaming, says that dreams are our way of regulating emotions – particularly fear. Normal dreams help us eradicate fear and process other emotions properly. Nightmares, on the other hand, occur when this regulation fails.

A third model has an entirely different perspective on the meaning of dreams. The Activation-Synthesis Model says that dreams are actually random. They are our brains’ way of making sense of activity that goes on while we sleep. Our brains take signals from parts like the amygdala and the hippocampus and try to interpret them, resulting in dreams. This doesn’t mean dreams are meaningless, though! As J. Allan Hobson, one of the Harvard psychiatrists who proposed this theory, said: “Dreaming may be our most creative conscious state, one in which the chaotic, spontaneous recombination of cognitive elements produces novel configurations of information: new ideas.”

Each of these models provides a unique perspective into what dreams mean, and there are many more theories out there! Dreams show us how creative our brains can be – and who knows what else we can learn from them? Take time and reflect on your dreams, and perhaps you’ll tap into a new perspective not yet thought of!

Sleep Is Essential for Success!

If there is one important takeaway from this, it’s that sleep is essential for success! No matter what, we need to get the right amount of sleep in order to be healthy and ready to accomplish our figurative dreams. As for our literal dreams … well, it’s open for you to discover what they mean! We have so much yet to learn about the science behind sleep and dreams; you may make the next discovery!

If you want to learn more about the importance of developing habits and reaching your dreams, check out my book, Dream Big!: How to Reach for Your Stars. In it, I talk about the importance of sleep as well as other healthy habits that will help you reach your full potential!


  1. Colin Bird says

    This is incredible.
    Hopeful, and grateful to continue learning vastly from this profound exploratory thinking so as to better open audience’s minds/eyes in my own field. Thank you for this awesomeness.

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