How rest can lead to insight:
[R]esearchers gave a group of students a tedious task that involved transforming a long list of number strings into a new set of number strings. Wagner and Born designed the task so that there was an elegant shortcut, but it could only be uncovered if the subject had an insight about the problem. When people were left to their own devices, less than twenty per cent of them found the shortcut, even when given several hours to mull over the task. The act of dreaming, however, changed everything: after people were allowed to lapse into R.E.M. sleep, nearly sixty per cent of them discovered the secret pattern. Kierkegaard was right: sleeping is the height of genius.
The Dish 