In my most productive projects, I go through arbitrary work-crash cycles, perhaps 36 hours awake, who knows how long asleep. Though, I can't imagine it working on a schedule. I failed a semester of University trying to sleep less than four hours each night and couldn't separate my own thoughts from the world around me. Stress and lack of sleep are a hellish combination. Isn't that a well documented torture: sleep deprivation through forced standing, flashing lights, and loud dissonant music, until submission?
But trying to sleep 4 hours a night and then failing does not mean that something like uberman can't work. Of course, it's notoriously hard to prove a negative, but still
On an unrelated note, this is mightily interesting:
It was Keith Hearne (1978), of the University of Hull, who first exploited the fact that not all the muscles are paralyzed [during sleep]. In REM sleep the eyes move. So perhaps a lucid dreamer could signal by moving the eyes in a predetermined pattern. Just over ten years ago, lucid dreamer Alan Worsley first managed this is in Hearne's laboratory. He decided to move his eyes left and right eight times in succession whenever he became lucid. Using a polygraph, Hearne could watch the eye movements for sign of the special signal. He found it in the midst of REM sleep. So lucid dreams are real dreams and do occur during REM sleep.