If your head were cut off, would you still be able to see or otherwise move it, even for just a few seconds?
This concept perhaps first appeared during the French Revolution, the very time period in which the guillotine was created. On July 17, 1793, a woman named Charlotte Corday was executed by guillotine for the assassination of Jean-Paul Marat, a radical journalist, politician and revolutionary. Marat was well-liked for his ideas and the mob awaiting the guillotine was eager to see Corday pay. After the blade dropped and Corday's head fell, one of the executioner's assistants picked it up and slapped its cheek. According to witnesses, Corday's eyes turned to look at the man and her face changed to an expression of indignation. Following this incident, people executed by guillotine during the Revolution were asked to blink afterward, and witnesses claim that the blinking occurred for up to 30 seconds.
Another often-told tale of demonstrated consciousness following beheading dates to 1905. French physician Dr. Gabriel Beaurieux witnessed the beheading of a man named Languille. He wrote that immediately afterward, "the eyelids and lips ... worked in irregularly rhythmic contractions for about five or six seconds." Dr. Beaurieux called out his name and said that Languille's eyelids "slowly lifted up, without any spasmodic contraction" and that "his pupils focused themselves" [source: Kershaw]. This happened a second time, but the third time Beaurieux spoke, he got no response.
http://science.howstuffworks.com/life/inside-the-mind/human-brain/10-brain-myths6.htm
