I was in Paris the first time it happened: I woke up in bed and couldn’t move. Shit, I thought. Am I dead? Blinking out of existence would have been bad, but spending eternity staring at the lid of a coffin seemed much, much worse. Panicked, I tried to will my consciousness into leaving my body or dissolving into the ether. But my mind, like my body, wouldn’t budge.
What I experienced that morning wasn’t death, but something much weirder: sleep paralysis, a condition where the extreme loss of strength (called muscle atonia) you experience during REM sleep doesn’t stop immediately when you wake. It’s mostly harmless, though some sufferers experience terrifying hallucinations. I never did. And even though I woke up paralyzed a few more times during the rest of my time in Paris, when I came back to the US, the episodes stopped completely.
The idea that moving across borders might affect the brain in odd ways isn’t new. A study published in BMJ this March, for instance, found that refugees in Sweden were 3.6 times more likely to experience symptoms of schizophrenia than the native-born population. Non-refugee immigrants, both first- and second-generation, have been shown to have an elevated risk for the disorder, too.