Scientists at Yale University are experimenting with a way to re-animate a human brain after a person has died, but not everyone is excited about the idea of creating life after death.

The university announced last month that it found living cells in the brains of pigs that had been slaughtered, and was successful in resurrecting the brains, WMUR reported. Scientists said it is possible to restore some brain function as after death, which could then become a way to keep a human brain alive after the person has been killed.

But as the Telegraph reported, that has raised some major concerns among ethicists.

Benjamin Curtis, a lecturer of ethics and philosophy at Nottingham Trent in the U.K., said it could be a “living hell” for a person whose brain is re-animated outside of their body after death if the experiment were to restore consciousness.

“Even if your conscious brain were kept alive after your body had died, you would have to spend the foreseeable future as a disembodied brain in a bucket, locked away inside your own mind without access to the sense that allow us to experience and interact with the world,” he told The Conversation. “In the best case scenario you would be spending your life with only your own thoughts for company.”

The scientists at Yale University disagree. Stephen Latham, director of the Yale Interdisciplinary Center for Bioethics, said the brains that are re-animated are not “alive” in the way we think of it.

“The brain is not conscious,” he said. “It’s not a pig brain in a vat wondering where it is. … It isn’t the sort of sci-fi thing where you wake up and think, ‘I can’t see anything or feel anything.'”

The pig brains that were successfully re-animated were taken from a slaughterhouse and a system of tubes and reservoirs, called BrainEx, were then used to carry oxygen to the brain stem and other parts of the brain, WMUR reported.

The re-animated brains could be used to test for brain diseases, like Alzheimer’s, Latham said. Researchers could also use the brain tissue to see what effects certain drugs have on it.

Given the ethics concerns of the experiments, the Yale researchers have called for public debate on the topic, and ethicists agree.

“The techniques, even to a researcher, sound pretty ghoulish — so it is very, very important that there should be a public discussion about this, and not least because the researchers who have some investment can tell the public why it would be so important to develop such techniques,” Colin Blakemore, a professor the School of Advance Study at the University of London, told BBC News.

Spending eternity as a brain in a jar with only your own thoughts for company? I’ve felt traumatised by train journeys where I forgot my phone :( https://t.co/ZoEhPhfoh8 — Daniel Dawkins (@DanDawkins) May 7, 2018

Blakemore added that he would be uneasy with the idea of people keeping their brains in suspended animation with the hope of coming back to life one day once sufficient medical advances are made, and hopes that the experiment would not lead to that one day.