I wonder if the head stops thinking immediately, or sort of experiences the roll.
actually thats an interesting thought and somebody a hundret years ago was interested in that too...
http://allkindsofhistory.wordpress.com/2011/01/25/some-experiments-with-severed-heads/The head fell on the severed surface of the neck and I did not therefore have to take it up in my hands, as all the newspapers have vied with each other in repeating; I was not obliged even to touch it in order to set it upright. Chance served me well for the observation which I wished to make.
“Here, then, is what I was able to note immediately after the decapitation: the eyelids and lips of the guillotined man worked in irregularly rhythmic contractions for about five or six seconds. This phenomenon has been remarked by all those finding themselves in the same conditions as myself for observing what happens after the severing of the neck…
“I waited for several seconds. The spasmodic movements ceased. The face relaxed, the lids half closed on the eyeballs, leaving only the white of the conjunctiva visible, exactly as in the dying whom we have occasion to see every day in the exercise of our profession, or as in those just dead. It was then that I called in a strong, sharp voice: “Languille!” I saw the eyelids slowly lift up, without any spasmodic contractions – I insist on this peculiarity – but with an even movement, quite distinct and normal, such as happens in everyday life, with people awakened or torn from their thoughts.
Head of Henri Languille (before).
“Next Languille’s eyes very definitely fixed themselves on mine and the pupils focused themselves. I was not, then, dealing with the sort of vague dull look without any expression, that can be observed any day in dying people to whom one speaks: I was dealing with undeniably living eyes which were looking at me. “After several seconds, the eyelids closed again, slowly and evenly, and the head took on the same appearance as it had had before I called out.
“It was at that point that I called out again and, once more, without any spasm, slowly, the eyelids lifted and undeniably living eyes fixed themselves on mine with perhaps even more penetration than the first time. The there was a further closing of the eyelids, but now less complete. I attempted the effect of a third call; there was no further movement – and the eyes took on the glazed look which they have in the dead.
