As a collective event, dreams unite us.
They can be wacky, scary, symbolic or happy, but exactly why we dream remains unknown.
While there are prevailing theories and conspiracies, beyond the science and mystery, the world of dreams can be magical.
The technical meaning of a dream is a series of thoughts, images and sensations occuring in the mind during sleep. But what more do we and don’t we know about the science of sleep?
Preparing for scenarios to come
Our brains learn by creating images that we can use to predict behaviours. For example, when you consider eating your brother’s leftovers, you weigh the risks and rewards. By doing so, you are predicting the reactions of those around you and the impacts on yourself. Dreams are no different.
According to a study published by Cornell University, there are two types of dreaming that can help explain this.
Adversarial dreaming allows the brain to play tricks on itself. By randomly combining memories, your brain invents scenarios you’ve never experienced before.
Contrastive dreaming focuses on pattern recognition. Like studying, you take away key pieces of information and dump unnecessary knowledge.
Another prominent theory is that dreams aren’t particularly meaningful — they’re simply signals sent through your brain systems, pulling random memories and thoughts. This is known as the activation-synthesis hypothesis.
Sleeping is learning
When you’re cramming late into the night for an early-morning exam, you’ve likely remembered it’s easier to retain information if you get a good sleep and skip that all-nighter.
Scientists at the Salk Institute for Biological Studies found unconscious brain states may help us remember events and facts. Brain cells change and form connections during sleep, helping us remember things and form complex ideas.
According to the National Library of Medicine, memories are stored in the hippocampus. Connections called synapses begin to form when you want to remember things, which can lead to more complex memories called memory circuits. These are developed through sleep.
There are five stages of sleep
According to Medical News Today, there are five stages of the sleep cycle:
- Light sleep with slow eye movement and reduced muscular activity;
- Brain waves slow down and eye movement halts;
- Delta (extremely slow) brain waves begin between smaller, faster brain waves;
- Almost exclusively delta waves, otherwise known as “deep sleep”;
- Rapid eye movement (REM)
During REM our eyes dart in different directions while our limbs become temporarily paralyzed, and the rate of many body functions increases. If people wake up during REM, they often recall their dreams. While paralyzation sounds scary, it safeguards the body from enacting dreams in the physical world.
Colourful dreams might be a result of technological advances
Approximately 12 per cent of people dream in black and white, according to Healthline.
Between 1940 and 1950, those number were much higher. The National Library of Medicine found that the shift from black and white to coloured media may be partially responsible for the shift.
Sleeping face-down can cause certain types of dreams
Have you ever had a dream about showing up naked to somewhere you shouldn’t be? Try flipping onto your back, because according to Healthline, dreams about sex, nudity, swimming, being locked up and being unable to breathe are associated with sleeping on your front.
While science has yet to uncover the full extent of dreaming, one thing is certain: dreaming is a collective part of life that helps us form functional thoughts and feelings, all while entertaining the mind.
Featured graphic by Alisha Velji.
