Human Head Transplants: Where the Science Stands, and Why the Ethics Are So Complicated
Learn more about human head transplants. Are they possible? And what moral dilemmas do they bring forth?
Key Takeaways on Human Head Transplants:
- Human head transplants are also known as cephalosomatic anastomosis, and at the moment, are not actually possible and likely won’t be before 2030.
- Some researchers have tested a human head transplant on cadavers; they’ve also been tested on animals. While it may be possible in the future, it’s still a very difficult procedure, morally and in practice.
- One of the debates with human head transplants is the moral dilemma of who is who? Does the new head belong to the body, or does the old body belong to the new head?
It sounds like pure science fiction. Remove a healthy human head from a dying body, connect it to a different healthy body, and bring “the person” back to consciousness. Equal parts Frankenstein and Futurama, it’s a premise so bizarre it stretches believability.
But perhaps surprisingly, a few scientists have argued a human head transplant isn’t entirely out of the realm of possibility. Some have even attempted versions of a head transplant in the lab. Nonetheless, many experts argue a head transplant shouldn’t be attempted on humans until we’ve thoroughly grappled with the enormous scientific and ethical hurdles it presents.
Yet whether or not a human head transplant ever actually becomes feasible, the questions it raises are real — and sometimes deeply unsettling.
What Is Needed For a Human Head Transplant?
Let’s get one thing clear from the start. A human head transplant, sometimes called a cephalosomatic anastomosis, is not currently possible. However, some researchers argue it could be possible in the relatively near future.
In addition to keeping a detached human head alive and viable during the procedure, the surgery would require reattaching dozens of muscles, major arteries and veins, the trachea, esophagus, spinal column, and most challengingly, the spinal cord. And the latter is the real deal-breaker.
Currently, the intricate and delicate human spinal cord cannot be severed and reconnected in a way that preserves motor or sensory function. Even among patients with spinal cord injuries, regenerative treatments are limited, experimental, and largely ineffective.
Who Is Who After a Human Head Transplant?
“The most perplexing element of head transplants might be determining who the donor is and who the recipient is,” says Karen Rommelfanger, a neuroethicist and Founder and Director of the Institute of Neuroethics. “While many of us might equate our identities to our brains and our intellect, many cultural traditions would understand their identities as the constellation of their relationships.”
If you receive a heart transplant, Rommelfanger says, you’ll likely say that you are still you.
“But if you receive a brain transplant,” she asks, “what would your answer be? Are you still you? The answer really isn’t only a scientific one, but one that depends on societal beliefs.”
Dog and Monkey Head Transplants
Although the concept sounds futuristic, scientists have been exploring head transplantation since the early 20th century. In 1908, French surgeon Alexis Carrel and American physiologist Charles Guthrie performed the first dog head transplant. The dog demonstrated some visual and aural reflex movements after the procedure, but it was euthanized after only a few hours because its condition quickly deteriorated.
In 1954, Soviet scientist Vladimir Demikhov, a pioneer of lung and heart transplantation, also performed a series of controversial dog experiments that involved grafting the head and upper body of a puppy onto an adult dog. While the hybrid animals survived as long as 29 days, they eventually succumbed to organ rejection or surgical complications.
Will We Ever Do Human Head Transplants?
Even if science catches up and human head transplants become a real option in the future, there are enormous ethical concerns surrounding the procedure that still need to be addressed.
“The biggest concerns are around disrespect for human dignity, lack of appropriate consent, and potential for undesirable, even debilitating changes to identity,” Rommelfanger says. For instance, who is the person after a successful head transplant? The individual who owned the body? Or the one with the original brain?
And that’s not the only gray area.
“In the case of human head transplants in China,” she says, “it’s possible that bodies or heads for individuals could come from people who might not really be ‘dead.’”
In the U.S., the Uniform Determination of Death Act (UDDA) defines death primarily as the irreversible cessation of all brain activity. But not every country or even state shares that definition.
“[Y]ou can be dead in one state but not in another,” Rommelfanger says.
And then there’s the issue of justice.
“Virtually every new technology or intervention that requires expensive equipment and rare expertise is not equitably distributed. This intervention would be no different in that regard,” Rommelfanger says. “But there is a unique worrisome kind of exploitation that could happen with even the experimental phases of this work related to consent, or lack thereof. One wonders, where are the bodies coming from for these experiments?”
A Sci-Fi Concept That Confronts Real-World Limits
The notion of a human head transplant remains one of the most sensational and controversial ideas in modern medicine. While it’s still firmly in the realm of science fiction for now, the questions it raises are all too real. From who we are as individuals, to how we define death, to the boundaries of consent and exploitation, head transplants press us to really consider not just what medical science can do, but what it should do.
“I ran a journal club once on one of Canavero’s scientific articles about the procedure, and we received a powerful statement from a neurosurgeon,” Rommelfanger says. “They said, in reference to the head transplant procedure, ‘There are some things worse than death.’”
* Jake Parks is a freelance science writer and editor for Discover Magazine, who covers everything from the mysteries of the cosmos to the latest in medical research.