This was very interesting and a technique that I had never heard of but was implicitly using myself. I have a bad back and after a few hours of work at my desk I often have to lie down and rest my back and end up napping. I'd rest by reading on my laptop but would sometimes drift off to sleep with my laptop resting on my chest or stomach and eventually the laptop sliding off my body would awake me and I would have new ideas to pursue on problems that I was working on. I think I'll put a notepad nearby and try to capture more insights when I wake up.