“They called it REM sleep for years,” Ursula Le Guin wrote, in her novel The Lathe of Heaven. “It’s a hell of a lot more than that, though. It’s a third state of being.”

Dreaming represents a state in between consciousness and unconsciousness, and this year I’ve been trying to get on top of what we know about this universal and mysterious experience.

I went to a dream conference in Arizona , and spent the night in a dream lab in Swansea, UK. There I learned about research providing evidence, for the …