Why do we dream
every night?
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Kuansong de Xianggu asks: why do we dream every time we sleep? But you probably know someone who says: I never dream. I just sleep straight through. So who's right? The answer is hidden in an experiment about waking people up.
In 1953, two scientists in Chicago taped thin wires beside sleepers' eyes, and watched those eyes all night long. They found that after a while, the eyes dart left and right under the lids, as if watching a movie. Right then, they gently woke the sleeper and asked: what were you just doing?
Add up dozens of later experiments, and about eight times out of ten, people say: I was dreaming! Wake them while the eyes are still, and some report dreams too, just fainter, more like thinking. So a dream is like a movie playing inside your brain.
About every ninety minutes, the brain starts a new showing, four or five a night, and the showings get longer toward morning. Then why do we so often wake up remembering none of them? The part of your brain that saves memories is like a camera operator. While you sleep, it dozes too.
After you wake, it takes about two minutes to get going. A dream lingers only briefly, and fades before it's recorded. Another guess: while you dream, the brain's 'remember this' signal is almost switched off, so dreams don't stick. That part isn't settled yet. So usually you only catch the showing that's on when you wake, and just its last few seconds.
But why does the brain play movies at all? Honestly, scientists don't know for sure. The idea with more evidence: the brain is sorting the day, saving what matters, stitching new pieces to old ones, which is why dreams feel so patchy. Some studies suggest: dreams replay hard feelings, so the next day hurts a little less. Others think dreams are just a side effect of the brain at work.
Back to our two people. Almost everyone gets these showings every night. People who never dream usually just missed the recording. A rare few report no dreams however they're woken, and no one knows yet if they truly don't dream, or forget too fast. So the answer: you dream every single night. Most of it just never gets recorded.
Tomorrow morning, before you move or grab your phone, close your eyes and think back for one minute. What did you catch? Come back and tell Kuansong de Xianggu, and us.
One dreams every night,
one never does
Some people dream every night. Others say they sleep straight through. Who’s right?
The answer is hidden in an experiment about waking people up.
Wake them while
their eyes dart
In 1953, two scientists in Chicago taped thin wires beside sleepers’ eyes and watched all night. After a while, the eyes dart left and right under the lids, as if watching a movie.
Right then, wake the sleeper and ask: what were you just doing?
About 8 times out of 10, people say: I was dreaming!
Wake them while the eyes are still, and some report dreams too — fainter, more like thinking.
Four or five
“brain movies” a night
About every 90 minutes, the brain starts a new showing. Four or five a night, and they get longer toward morning.
The dozing camera operator
Another guess: while you dream, the brain’s “remember this” signal is almost switched off. Not settled
Why does the brain
play movies?
Scientists don’t know for sure. A few ideas:
Try it tomorrow:
don’t move yet
When you wake, don’t move or grab your phone. Close your eyes and think back for one minute.
Give the camera operator time to start, and you might catch the last showing.
Most of it just isn’t recorded.
Quick check
What usually explains people who say they never dream?
Almost everyone gets four or five showings a night, but the brain's recorder needs two minutes to start after you wake.
