I spoze if I axxed 1,000 peoples to guess a number between 1 and 100, they would all "guess" 13, eh, Kicky?
"The current medical consensus is that life does survive, for a period of roughly thirteen seconds, varying slightly depending on the victim's build, health and the immediate circumstances of the decapitation. The simple act of removing a head from a body is not what kills the brain, rather, it is the lack of oxygen and other important chemicals provided in the bloodstream....the second question is 'how long does the victim remain aware?' While the brain remains chemically alive, consciousness can cease immediately, caused by the loss of blood pressure...If that weren't to happen immediately, an individual could in theory remain self-aware for part of the thirteen-second period."
LINK
Pure speculation, ya figure?