We’ve all had those crazy, vivid dreams that trigger a Google search the second we wake up. But what do dreams mean, if anything, about our waking lives? We spoke with medical experts who study all the weird ways our minds function to better understand just what goes on in our heads after we doze off. Read on to learn what dreams actually are and why we have them.
What are dreams?
Before we dive into what lies beneath those hyperrealistic dreams you spend way too much time overanalyzing in the AM—you know, the ones about loosing all your teeth or finding yourself unexpectedly giving birth—it’s important to understand what dreams are. A sign from the universe? Your anxiety making its debut as an subconscious movie director?
“Dreams represent sleep mentation”—aka imagery and thinking during sleep—”and there are many dimensions to that,” says David Neubauer, M.D., associate professor of psychiatry and behavioral sciences at John Hopkins Bayview Medical Center. In other words, dreams are a series of fragmented visions and thoughts that come to us while we’re unconscious.
Dreams occur mostly during REM sleep, also known as paradoxical sleep—a sleep stage in which “your brain is moderately active and thinking about things and processing information,” says Philip Gehrman, Ph.D., associate professor of clinical psychology in psychiatry at the Hospital of the University of Pennsylvania. “But there’s this disconnect between what is going on in our brain and reality.” (If you’re curious about where REM sleep got its name, Gehrman says that while our eyes remain very still throughout most of the sleep cycle, it’s during this stage that our eyes start to move around, even corresponding to the dreams we’re having at that moment. “If we dream that we see a bird flying through the air, our eyes will actually look up as if we’re looking at the bird,” Gehrman says.)
Most of our dreams take place during REM sleep but we can also have dreams throughout other stages of the sleep cycle. “We now understand that you can dream in other stages of sleep as well, however, non-REM dreams are the ones that are bland, boring, and usually not too interesting,” says Gehrman. So if you find yourself dreaming of waking up and heading to the bathroom to brush your teeth—a normal morning routine—chances are you’re out of the REM stage.
Why do we dream?
Do dreams serve a purpose besides making us wonder what the universe could possibly be signaling? Scientists believe that they do but there’s still a lot of research to be done before we get close to a definite answer. “There are two types of theories,” says Gerhman, “some are about the function of dreaming and other theories are about the function of REM sleep, where the idea is that there is something happening in the brain during REM sleep that’s really important.”
So what exactly are our minds trying to achieve in middle of the night? Gerhman explains that it’s during the REM stage when all the new information we learned during the day gets incorporated into our memory network. “The information in your brain doesn’t exist in independent memories, the information is connected to each other—nd those connections form during REM sleep,” he says.
In a pivotal dream study published in the journal Science, a group of participants played Tetris on and off for a period of several days. On game days, researchers would wake the participants every few minutes in the first hour of when they fell asleep—they discovered that most recalled dreaming of floating objects that moved just like in game. Gerhman says that takeaways like these provide evidence that our dreams are one of methods adapted by our brains to work through the events of the day.