Dreams and Sleep
We know that our bodies use sleep to recover, heal, rest and to regain energy but very little is known about dreams. While we don’t know for 100% certainty, dreams are seen to play an important part in our mental and emotional health. Dreams are perhaps the most mysterious part of sleep.
What Are Dreams?
Dreams are a slideshow of images, ideas, emotions and thoughts that occur while we are sleeping. Why certain images and thoughts come up, no one really knows. It’s believed that our minds take these flashes and snippets of the world and piece them together into a story of sorts. This story is the “dream” that we remember.
The reason that dreams can seem so bizarre is that these “flashes” aren’t done purposefully. Instead, they are a random selection chosen for an unknown reason by our brains. A snippet of the sandwich you had for lunch and then a scary movie you watched a few days ago could turn into a monster-sized sandwich destroying your neighbourhood. It is more common that a person wakes up to think, “Wow that made no sense.” then they are to think, “that dream was completely logical.” That is simply the nature of dreams.
Historically, dreams have been looked at as messages from gods or other beings. Some still dissect dreams to look for direction in their lives or for insight into decisions they need to make. In fact, it was Sigmund Freud and Carl Jung at the tail end of the 1800s who put forth the idea that dreaming was all about our wishes, hopes and dreams that we were too afraid to say out loud.
Do Dreams Have Meaning?
As neurological tools and science have advanced, so has our understanding of why we dream. One theory, as explained by Scientific American, is that dreams are actually meaningless. Our brains randomly pull ideas and images from our memories and “dreams” are our human way of trying to make sense of the parts of these flashes that we remember. These images really have no meaning.
While the content of dreams themselves may be meaningless, this theory does have some holes. It is most likely that the purpose of dreams are not meaningless but actually quite meaningful. One of the biggest supporters to the idea that dreams do have purpose is that other animals aside from humans dream. Cats, dogs, sheep, goats, horses and even birds all dream. So dreams can’t simply be the result of human cognition and imagination. There has got to be some kind of biological function or necessity.
Main Theories for Why We Dream
There are a few major theories as to why we dream and why dreams do have meaning.
1. Memory
One of the most widely supported theories on the purpose of dreams is that they give our brains a way to process memories. Our brain decides for us what memories are important and which ones maybe aren’t so valid. Short term and long term memory could be associated with this “save or dump” process of the mind.
2. Fight or Flight
While the entire brain is engaged while a person is dreaming, the amygdala - the part of the brain associated with fear and the “fight or flight” response - is increasingly active. The connection between the amygdala and our emotions supports the idea that some type of emotional work is being done while we dream. Some theories think that this is about fine-tuning our flight or fight response and working through complex emotions at a time when our bodies are at rest.
This could also be the reason that emotions seem to be heightened in our dreams. Scary things are extra scary, happiness is euphoric and we can experience extreme highs and lows.
3. General Health
Brain scan of non-rem and REM sleep. Image borrowed from EarthSky.
Dreaming takes place during REM sleep. Rapid Eye Movement - REM - is one of the sleep stages and is a natural part of the sleep cycle. REM sleep is when our brains are most active and when our bodies become “paralyzed” in a sense. This loss of muscle tension is believed to be a direct response to dreaming - your body can’t thrash or jump based on what happens in your dreams. Breathing rate can also increase and blood pressure can go up during this sleep stage.
Another major reason that dreams are connected to memory is that REM sleep is linked to learning, decision making and emotional stability. Studies have shown that those who do not get REM sleep actually have difficulty remembering things from the previous day. Since dreams take place during the REM cycle, they’re also linked to these health benefits.
What Causes Dreams?
Since dreams take place during REM cycle, the connection between long, vivid dreams and little or no dreams can be directly related to REM sleep cycles. Inadequate sleep for a few days can result in longer and deeper levels of REM sleep. This means longer and more vivid dreams.
Aside from the biological function that they simply happen, the specifics as to what causes dreams is also up for speculation.
What You Need To Know About Dreams and Sleep
Dreams are a natural neurological function that happens to all kinds of creatures including birds, cats, dogs, horses and humans. While technology is helping to shine a light on dreams and their purpose, there is much we do not know about dreaming. What is known, however, is that dreaming is directly related to the part of our sleep that helps us learn, grow, process emotions and develop memories. As technology advances in neurological science, our knowledge of dreams will grow as well.