The Science of Dreaming

If dreams were movies, they wouldn’t make a dime. They’re often banal, frequently fleeting and they’re screened for an audience of just one. As for the storyline? You’re in a supermarket, or is it Yankee Stadium, shopping with your second-grade teacher until she turns into Queen Elisabeth. Then you both go for a swim and wake up. So what is dreaming and why do we dream?



Dreaming in science is called rapid eye movement sleep (aka REM). Typically REM occurs about an hour after we fall asleep and cycles through three to five times during an average night’s sleep, which means about 20% of our total time sleeping – about 2 hours – is devoted to dreaming.


Modern psychologists and neurologists, armed with imaging equipment including PET scans and MRIs, have taken things to a deeper and more technical level, speculating that dreaming is the brain’s way of dumping excess data, consolidating important information, keeping us alert to danger and more. Dreaming is like a psychological thermostat, preset to keep us healthy, balanced, and ready to react to both threats and opportunities in the waking world. Post-traumatic nightmares show what happens when an experience is too intense and painful to process in a normal way, knocking the whole system out of balance. Dreaming is great, and makes us more balanced in the end.