"Dreams are toys," as anyone who has been to the surreal, wonderful, or downright insane places our dreams can take us will agree. Yes, our dreams are playful, but what happens behind closed lids? Why do we dream in the first place?
Nobody can be certain. However, we all know what happens in our brains when we sleep. Four phases of sleep result in four separate types of electrical activity in the brain, with the right half receiving the most attention. We quickly progress from level 1 to 4 when we fall asleep, and we surface and descend through these stages during the night.
Our eyes shift quickly back and forth during another stage of sleep, giving this period its name: rapid eye movement or REM sleep. People typically report having dreamed at this stage – strangely, physical rest and neurological activity coexist here. Since the electrical activity in the brain during this dreaming state of sleep is similar to that measured when we are awake, it is also known as paradoxical sleep. It's also where we go when we're under hypnosis. We will toss and turn during the other four stages of sleep, but our muscles become paralyzed during REM sleep, preventing us from acting out our dreams.
Humans spend roughly a quarter of their nighttime absorbed in dreams, implying that they must serve a function. But what exactly is it? There are several hypotheses as to why we dream. Most of us have had dreams that have aided us in working through stressful thoughts, feelings, and interactions, leaving us feeling more grounded during the day. One hypothesis suggests that dreams are a way for us to reset our minds, focus on and discuss the problems of the day, and consolidate.
REM sleep is when our brains dump everything on the metaphorical table, find out what's there, sort and file it, or fit it to current memories and file it accordingly. This indicates that in humans, REM sleep is essential for the development of emotional memory. But that doesn't justify why, despite having nothing to resolve, babies in the womb spend half of their time in REM sleep. Dreaming decreases in childhood after this stage, indicating that dreams are a part of how immature brains work. Their sparse neuro-wiring needs assistance in joining and establishing links, which REM sleep provides. However, because of the way the brain battles for REM sleep to occur, there must be a significant advantage to it in our lives.
If you're awakened during REM sleep (and therefore possibly dreaming), your brain will try to compensate the next night by entering REM sleep more often and for longer. In one study, participants were awakened every time they entered REM sleep. This occurred up to ten times on the first night, but after six nights of repeated waking, their brains attempted to reach REM sleep as many as 33 times. Parents of awake babies are familiar with this sensation, which causes dreams and reality to become increasingly muddled.
We're not the only ones who daydream. All mammals, as well as birds, tend to dream on occasion. This lends credence to the hypothesis that dreaming is merely a neural reaction to biochemical and electrical changes. The brain unites past, current, and future experiences during dreams; processing knowledge from the first two prepares us for the third. This may also mean that dreams serve as a defensive mechanism, preparing us to face risks, hazards, and challenges.
Depression, anxiety, and post-traumatic stress disorder may all trigger nightmares, supporting the idea that dreams are the brain's way of sorting through difficult thoughts, feelings, and experiences. Since so much dreaming occurs in the right hemisphere, one last hypothesis considers its position as a creative portal that fuels imagination and problem solving. One way to overcome real-life creative issues is to practice lucid dreaming, in which you can train yourself to control or direct your dreams to follow a specific path.
Despite all of these hypotheses, the cause and role of dreaming remain elusive, making it difficult to understand why we dream. Where we go while we sleep is still a mystery, whether it is insightful, therapeutic, or a biological process. But there's a certain pleasure in not learning. Sleep's mysteries have been the subject of novels, music, and literature. Dreams are made of this material.