Mind & Body

How Long Does a Decapitated Head Remain Conscious?

European history is littered with figures who lost their heads. Gruesome rumors surrounding those beheadings also made their way into the historical record — stories of heads that grimaced, blushed, or even tried to talk after they had been separated from their bodies. But is this all just frightening fiction? How long can a severed head survive?

Off With Their Heads!

As you might expect, the tales of heads surviving after decapitation are pretty gruesome. In England, both King Charles I and Anne Boleyn reportedly tried to speak after the executioner's sword fell.

And of course, France was awash in blood for a decade as a result of the French Revolution. Marie Antoinette's last utterance was an apology to her executioner for stepping on his foot. The headsmen were not nearly as polite to their charges: When the guillotine ended the life of Charlotte Corday, the woman who assassinated revolutionary leader Jean-Paul Marat, the executioner supposedly picked up her severed head and slapped its cheeks. Witnesses swore they saw her face turn red in anger.

A German researcher who spoke out against the use of the guillotine in the midst of the revolution even claimed he saw some unhitched heads grimace upon inspection by a doctor. Are these stories really possible? To find out, you first need to learn something about the brain.

Separation Anxiety

Your brain is arguably the most important organ in your body. It controls all other organs and bodily systems and is responsible for your thoughts and feelings, memories, and movements. Your brain needs oxygen to carry out all the incredible undertakings that it does — a lot of it. The brain accounts for about 20 percent of oxygen used by the body.

The flow of oxygen to the brain is interrupted the moment blood vessels in the neck are severed. The sudden drop in blood pressure and rapid loss of both blood and oxygen would quickly send the brain into a coma, with death following shortly after.

But it may take a few seconds for the brain to enter that unconscious state. Researchers have found that some animals' bodies continue to function seemingly normally after decapitation. This is where we get the phrase "running around like a chicken with its head cut off" — the birds have been observed walking around headless for a few seconds. The most famous fowl to survive headlessness was a lucky clucker named Mike who lived 18 months longer than intended thanks to an imprecise ax swing that kept his central nervous system intact and a well-timed blood clot that stopped him from bleeding out.

What if human heads can survive for the same length as your average chicken head? Count out four seconds and consider how much you're able to perceive about your surroundings. It certainly seems like enough time to lend credence to those historical rumors, or a more contemporary tale in which an Army veteran in 1989 recalled a car accident in which his friend's decapitated head expressed grief and terror upon realizing that it had been separated from its body. This seems worse than immediately dying, doesn't it?

Braindead? Maybe Not

It's possible that decapitated heads are conscious in those final seconds. What's more likely, though, is that these dreadful recollections result from the brain's final brainwave. Many of the body's essential functions are made possible by the brain's transmission of electrical signals. Scientists have found that the brain can continue functioning for up to 30 minutes after the heart stops. The brain sends one final electrical wave, which could cause the muscles it's still attached to (in this case, those beneath the face) to contract or twitch.

What's unclear is how long the brain remains conscious after being separated from its body. As discussed earlier, the rapid blood loss probably sends it into a coma within seconds. But survivors of near-death experiences are able to recall what was going on around them after their heart stopped, which suggests that the brain remains aware despite the body's lack of clinical consciousness.

At the end of the day, we don't yet know whether people's heads keep thinking and feeling after they've been cut off. Here's hoping none of us ever has to find out.

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Dive deeper into the science of the dead with "Stiff: The Curious Lives of Human Cadavers" by Mary Roach. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Steffie Drucker October 25, 2019

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