N1 Sleep Stage [Hypnagogia]

N1 is a non REM (rapid eye movement) stage of sleep that has been associated with increased creativity.

Dali and Einstein both reportedly slept with objects in their hands that would wake them when from the noise of dropping the item when they started to fall asleep. They indicated they were more creative and had inspirations for their work.

Learn more:

Need a Creative Boost? Nap Like Thomas Edison and Salvador Dalí

Quick catnaps may spark creativity | National Institutes of Health (NIH)

Targeted dream incubation at sleep onset increases post-sleep creative performance | Scientific Reports