sleep twitches
In dreams, our brain comes alive with sensorial content while our body lies motionless between the sheets. sometimes though, we happen to make those short, jerky movements out of nowhere.
The theory that sleep twitches are physical echoes of our dreams is pretty appealing. I experience this firsthand: the twitches that jolt me awake when I’m falling asleep often match up with the dream imagery. For exemple, I would suddently jerk my arm because a volleyball was speeding towards me in my dream.
Mark Blumberg spent decades doing research on this (very niche) topic. He created this impressive collection (here) of animal twitching in their sleep —including bees, bats, cheetahs and pigeons. In this great article (What are dreams for, here), he rejects this cool dream-echoes view and thinks the other way around: twitches may be sending signals to the brain. It turns out that bursts of activity in the sensorimotor cortex follow the twitches. Blumberg interprets this as the idea that the brain uses REM sleep to “learn” the body.
Illustration by Lina Müller. Check out her works here.