Heads alive after guillotining: any truth?

I’ve always been fascinated with the old stories about the French revolution and heads, after being separated from their bodies by Mme. Guillotine, showing expressions or actually making sounds.

This is horrendously gruesome, but I’d like to get to the physiological basis of this. One would imagine that the shock of a metal blade smashing through the back of one’s neck (well, all the way through!) would render one unconscious, but what is the physiological reason for this assertion?

I can see that the blood supply to the brain being cut off would result in very swift unconsciousness, but how swift is “swift?” Would the head still have time to understand what had just been done to it, indeed to realise the horror and be able to shout, or make a cry? (I guess no lungs precludes that.)

To diverge on an equally horrible tangent, I’ve heard that head transplants have actually been conducted with monkeys. What’s the deal with that?

One of Cecil’s favorite topics:

Do decapitated heads briefly remain conscious?

Does the head remain briefly conscious after decapitation?


Sorry! I should have done a simple search.