It’s a fascinating question: Why do we dream? There are a great many theories, and we are learning more all the time. For example, look how much incredible information is packed into this short video!
The science of dreaming is called oneirology. It’s a pretty modern science, of course – it didn’t exist for a long time simply because we can’t see another person’s dreams, nor can we easily control dreaming – and if you conduct survey-style analysis, by which I mean you come right out and ask people what they dreamt while sleeping, the data returned is remarkably unreliable – we tend to forget 95% of the dreams we have within 10 minutes of waking up. We forget a great portion of that 95% within mere moments of waking up. Our dreams just evaporate into thin air, and we are left none the wiser.
Why do our dreams evaporate so quickly? (Photo credit: @Doug88888)
But dreams have always fascinated us. That’s why we’ve spent so much time studying the behavior. Many cultures, historically, have viewed dreams as prophecies, or warnings – as if our own brains knew the future and the inner workings of our universe, but could only tell us these incredible secrets if we let ourselves drift into a completely vulnerable state – a state of sleep. Psychoanalysts have (and some still do) turned to dreams as symbols of a patient’s underlying mental health, as a key that reveals the root of our psychological concerns.
But oneirology is not dream analysis. Really, oneirology didn’t take off until 1952, when a PhD candidate at the University of Chicago – one Eugene Aserinsky – discovered what we now know as “REM sleep.”
Using a polygraph machine to record sleeping subjects’ brain waves, Aserinsky noticed a unique type of electrical activity that would transpire at certain intervals in a sleep cycle – intervals that could be recognized externally by the sleeper’s fluttering eyelids and “Rapid Eye Movements.” Aserinsky would awaken his subjects during this time, and when he did, they would confirm immediately that they had been dreaming.
Polysomnography (PSG) is a multi-parametric test used as a diagnostic tool in sleep medicine. (Photo credit: Wikipedia)
This kickstarted a rush of new research into sleep.
It was eventually discovered that the brain’s electrical activity during REM sleep closely mimics brain activity during periods of wakefulness – only certain waking-life brain chemicals are blocked during REM sleep, so your body becomes paralyzed.
We also discovered that animals can dream, as they too experience REM sleep. But why do we sleep?
Years after the University of Chicago study, researchers deprived lab mice of sleep and measured their ability to learn new tasks and remember how to complete old tasks. We know now that, if we are not allowed to experience REM sleep, we lose our ability to “replay” and “recall” memories – even memories related to tasks we have completed before. We are also less adept at picking up new skills.
Even rats dream – this is the “flower pot” experiment that measured the effects of sleep deprivation on learning and memory recall. (Photo credit: Wikipedia)
It is largely believed that REM sleep strengthens our neural pathways – our ‘memory connections’ – by “replaying” the electrical impulses that occur in our brain throughout the day (the same impulses that correspond to certain activities, tasks, and memories). In other words, our unconscious mind reviews our experiences from the previous day and gets rid of the “junk” while reviewing and cementing the more useful stuff. Dreaming is possibly our brain’s way of filling in the “gaps” in our memories: by associating muscle memories and learning with other past experiences, including things we thought throughout the day, into a sort of mnemonic “narrative” that helps us retain memory.
But ultimately, no one REALLY knows why we dream for sure. Our dreams are ours, uniquely, and are some of the last great mysteries of our world. The science of oneirology is still fairly young, and we certainly can’t wait to see what incredible sleep mysteries we ca solve in the future!
Your brain: still one of the unvierse’s greatest mysteries. (Photo credit: cloois)
About This Post:
This post was written by author Mike Bowman, a freelance journalist, avid reader, science fanatic, and sleep enthusiast.