Many of us can remember a dream we had last night, whether it was a tropical vacation, going to Mars, or eating lunch with the president, but can we explain why? What exactly is a dream, and are they nonsense? Or could something more be there?
First, a dream, according to researcher Kendra Cherry, includes “images, thoughts and emotions that are experienced during sleep” which can range in intensity, emotions, and complexity. Nightmares, the most frightful type of dream, tend to happen more often with individuals with PTSD, generalized anxiety disorder, or tendencies in dissociation. However, most dreams can happen to just about anyone.
So then, what is happening in our brains while we actively dream? According to Hobson and McCarley, who came up with the activation-synthesis model of dreaming, brain circuits become active during REM (rapid eye movement) sleep. This activity triggers the amygdala and hippocampus in the brain to create a ton of electrical impulses, which results in a series of thoughts, images, and memories, aka dreaming. Then when we wake up, we attempt to compile these thoughts and images together in a way that makes sense. In lucid dreaming, a rare type of dreaming where one is aware that they are dreaming, the prefrontal and parietal regions of the brain seem to play a role as well.
But why do we dream? The truth is, researchers still aren’t quite sure, but many theories have helped to explain at least some of the reasoning. Sigmeund Freud would say that dreams represent unconscious desires. Think about all the times you have a dream and ponder the meaning they had the next day. But this is only a fragment of why we might dream. Modern theories have suggested that dreams help to consolidate memories, process emotions, express our deepest desires, and help us practice confronting danger. According to Cherry, many researchers believe dreams are some sort of combination of these theories, but there are still some scientists who have suggested that some dreams don’t have any kind of purpose.
Among many theories is the self-organization theory of dreaming, which says that dreaming is actually a side effect of neural activity from the brain, while the brain is trying to consolidate memories while sleeping. Therefore this theory, supported by research, claims that while we dream, helpful memories become stronger, and useless memories fade. Yet another theory is the continuity hypothesis: that dreams are a sort of reflection of someone's life, like a replay of the past. Studies have shown that REM dreams are associated with emotional and instructive memories, in other words, less routine memories. Yet another theory suggests that dreams are for adaptive purposes. We simulate intense scenarios (such as forgetting to study for an exam, getting robbed, getting broken up with) in order to mentally prepare for them in real life.
So, next time you dream (and can remember it), try to think about the dream theories. Was your dream reflective of real life? Did it help you prepare for a life threatening scenario? Or was it just completely random?