One of the more sci-fi concepts in the area of digitizing death came from Nectome, a Y Combinator startup that preserves the brain for potential memory extraction in some form through a high-tech embalming process. The catch? The brain has to be fresh — so those who wanted to preserve their mind would have to be euthanized.

Nectome planned to test it with terminally ill volunteers in California, which permits doctor-assisted suicide for those patients. It collected refundable $10,000 payments for people to join a waitlist for the procedure, should it someday become more widely available (clinical trials would be years away). As of March 2018, 25 people had done so, according to the MIT Technology Review. (Nectome did not respond to requests for comment for this story.)

The startup raised $1 million in funding along with a large federal grant and was collaborating with an MIT neuroscientist. But the MIT Technology Review story garnered some negative attention from ethicists and neuroscientists, many of whom said the ability to recapture memories from brain tissue and re-create a consciousness inside a computer is at best decades away and probably not possible at all. MIT terminated its contract with Nectome in 2018.

“Neuroscience has not sufficiently advanced to the point where we know whether any brain preservation method is powerful enough to preserve all the different kinds of biomolecules related to memory and the mind,” according to a statement from MIT. “It is also not known whether it is possible to recreate a person’s consciousness.”