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Anatomists and other scientists in several countries have tried to perform more definitive experiments on severed human heads as recently as 1956.

Inevitably, the evidence is only anecdotal.

What appears to be a head responding to the sound of its name, or to the pain of a pinprick, may be only random muscle twitching or automatic reflex action, with no awareness involved.

At the very least, it seems that the massive drop in cerebral blood pressure would cause a victim to lose consciousness in a few seconds.