Lucid Decapitation sounds like the name of an alternative rock band but actually it's the title of an article on Damn Interesting by Alan Bellows regarding consciousness after beheading. There's no concrete evidence that a severed head is aware of it's fate, there are several interesting stories:
Read the entire article here.
A more recent account tells of an accidental decapitation in an automobile. In 1989, a U.S. Army veteran who served in the Korean war was riding in a taxi with a friend when it collided with a truck. The witness was pinned to his seat, and the friend was decapitated by the collision:My friend's head came to rest face up, and (from my angle) upside-down. As I watched, his mouth opened and closed no less than two times. The facial expressions he displayed were first of shock or confusion, followed by terror or grief. I cannot exaggerate and say that he was looking all around, but he did display ocular movement in that his eyes moved from me, to his body, and back to me. He had direct eye contact with me when his eyes took on a hazy, absent expression . . . and he was dead.
Trivia: The last execution by guillotine took place in Marseilles, France on September 10, 1977. The book of Revelation names beheading as the method of execution of Christian martyrs during the great persecution (Rev. 20:4).