[nitrogen]

I seem to recall similar research in rats or mice that found that "sleep" states occurred randomly when awake, and slowly synchronized into moving waves of "sleep" when asleep. If I am indeed remembering correctly, then it would seem more likely that this localized sleep mechanism is shared by all mammals, including humans. I'm sure many of us have experienced cycles of awareness while supposedly fully awake as well.

I wonder if it extends to reptiles, fish, etc.

[imjustsaying]

Evidence that birds sleep in mid-flight

http://www.nature.com/articles/ncomms12468

[Insanity]

Thank you for this interesting paper!