The book “Why We Sleep” discusses this. I believe it was Thomas Edison (I could be wrong) would fall asleep with a pan next to his chair, his hand over the pan,

The book “Why We Sleep” discusses this. I believe it was Thomas Edison (I could be wrong) would fall asleep with a pan next to his chair, his hand over the pan, and his hand full of marbles. When he’d fall asleep, his muscles would relax and he’d drop the marbles, waking him up. He used it to harvest ideas.