I read an interesting book a few years ago written by a guy exploring the different states our brain goes through during a twenty-four period; this included experimenting with polyphasic sleep. He spends (IIRC) a month living in a cabin in the wilderness, sleeping according to the rising and setting of the sun; after a week or so his body reset itself to a two-phase sleep cycle as described in the nytimes piece.

Overall a very enjoyable read: http://www.amazon.co.uk/Head-Trip-Fantastic-Through-Hours/dp...