Where human decapitation is concerned, there are anecdotal stories involving severed heads that seemed to respond to stimulus. The Conversation reported that, in 1905, a curious French doctor experimented at an execution by calling out an executed man’s name right after his head fell into a basket. 

The doctor wrote, “I saw the eyelids slowly lift up, without any spasmodic contractions — I insist advisedly 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.”

Discover Magazine reported that the same physician estimated that a human severed head could stay conscious for 25 to 30 seconds. A couple of hundred years before that, a showy executioner had made a spectacle of holding up the severed head of a young woman who had killed a revolutionary leader in France by slapping her cheeks. Spectators claimed that the woman’s facial expression changed to one of anger, per Discover. 

There isn’t a lot of opportunity to really study this phenomenon in humans — that would be frowned upon. However, scientists have experimented with decapitating rats while recording their brain waves via electroencephalography (EEG). According to the findings by researchers at Radboud University Nijmegen in the Netherlands, there is brain activity for several moments after the head is cut off from the body.  

“Consciousness is likely to vanish within some seconds after decapitation,” they wrote.