http://aeon.co/magazine/psychology/why- ... reativity/
The author has this to say:
My own night-waking confirms this difference between night- and day‑waking; my night brain definitely feels more dreamlike. When dreaming, our minds create imagery from memories, hopes and fears. And in the dead of night, drowsy brains can conjure up new ideas from the debris of dreams and apply them to our creative pursuits. In the essay ‘Sleep We Have Lost’ (2001), Ekirch wrote that many had probably been immersed in dreams moments before waking up from the first of the two sleeps, ‘thereby affording fresh visions to absorb before returning to unconsciousness. Unless distracted by noise, sickness, or some other discomfort, their mood was probably relaxed and their concentration complete’.
--Mike Perry, Inkling Books