Why we dream

Looking at the theories behind dreaming
Published March 1, 2021

Dreaming is a part of sleep, but no one fully understands why it happens. There are some interesting theories, though.

“Dreams happen in both REM (rapid eye movement) and NREM [non-REM] sleep, but it is the vivid ones during REM sleep that we most likely remember,” explains Monisha Bhanote, MD, FCAP, a triple board-certified physician and Yoga Medicine® teacher.

“Scientists are still trying to determine why we dream,” she says, but there are a few theories.

One theory is the dream rebound theory.

“In this theory research suggests that a dream results from suppression of something,” Bhanote says. “Dreams may also be a processing of our emotions of the day. This is linked to an early activation-synthesis model of dreaming, where certain parts of the brain including the limbic system, which includes the amygdala and hippocampus, create electrical brain impulses. This theory suggests that the impulses are signals that the brain interprets and we experience as dreams.”

Other theories, according to a Healthline piece, include one that posits dreams are a way to train our fight-or-flight response, and another that says dreams play a role in fostering creativity, and yet another that suggests dreams are a tool for memory building – storing important ones and purging unnecessary ones.

University of California professor and writer Matthew Walker, PhD, elaborates: “REM-sleep dreaming appears to take the painful sting out of difficult, even traumatic, emotional episodes experienced during the day, offering emotional resolution when you awake the next morning. REM sleep is the only time when our brain is completely devoid of the anxiety-triggering molecule noradrenaline. At the same time, key emotional and memory-related structures of the brain are reactivated during REM sleep as we dream. This means that emotional memory reactivation is occurring in a brain free of a key stress chemical, which allows us to re-process upsetting memories in a safer, calmer environment.”

And just last year, a pair of neuroscientists suggested another theory – that dreaming is a way our brain protects itself.

Bhanote adds that dreams are absolutely normal, however, when they start disrupting your sleep, you may want to look at a few things.

One thing to consider is your sleep hygiene, she says, which may be helpful in decreasing bad dreams.

Sleep hygiene refers to the things you can do to ensure good quality sleep. Tips include keeping your bedroom cool, creating a calm environment, avoiding looking at TV, computer and smartphone screens a couple hours before bed, and reserving your bedroom for the purposes of sleep and sex only.

“Additionally, having a toolbelt of relaxation techniques may help ease anxiety, which may be beneficial for more restful sleep,” Bhanote says.

Techniques to get you back to sleep may include practising mindfulness and meditation or reading – but experts say screens should be avoided.

Check out this article for natural ways to drift off to sleep.