In "Mitzukos Dream" you watch sleeping people, each filmed for one night with a willdlife camera that reacts to movement. So only the active parts of sleep were captured on film - the moments when we dream?

"Jun: You sleep too much. You spend half your life in your dreams. Mitzuko: Yeah, but sleep is wonderful. And when you're dead, you don't get to sleep ever again. Which means no more dreams. Mystery Train (Jim Jarmusch, 1989)"