During my college days, it was a well-known “fact” that I could learn by placing a book under my pillow at night. Information from the text would be transferred to my brain by osmosis. It never worked for me. And, it was terribly uncomfortable with some larger texts.
I have had success with sleep time problem solving, however. Before I go to bed, I read reference material that relates to the problem and try to work out the solution on paper. Then I go to bed. Sometime during the night, I will wake with the answer. I must write it down or I usually forget it in the morning. Then, I refine the solution during the next day.
This has worked well with mathematical problems. With people problems, the solutions are often based on ideal people and situations. Often, they do not work in the real word.
Dr. Barrett, a psychologist from Harvard University has studied problem solving during dreams. She notes that the process works for mathematical and artistic problems. In fact, it is still a mystery why we dream and why we must sleep.
Musicians use a similar approach to learn a song. They practice a song in the evening. The last practice of the evening is a perfect practice. Then, they stop and go to bed. This shortens the process of learning songs. It’s okay if the practice is at a slower tempo as long as the rhythm and notes are correct.