Frozen love: when Kim Suozzi was diagnosed with a terminal disease at age 21, she and her boyfriend chose to freeze her brain with the hope that they might one day reunite.

• Author: Harmon, Amy
• Position: SCIENCE

In the moments just before Kim Suozzi died of cancer at age 23, it fell to her boyfriend, Josh Schisler, to follow through with the plan to freeze her brain.

As her breath grew ragged, he fumbled for his phone. Fighting the emotion that threatened to paralyze him, he alerted the cryonics team waiting nearby and called the nurses to come pronounce her dead. Any delay would jeopardize the chance to maybe, someday, resurrect her mind.

It was impossible to know, on that cloudless morning on Jan. 17, 2013, in Scottsdale, Arizona, which fragments of Kim's identity might survive, if any. Would she remember their first, fumbling kiss in his dorm room five years earlier? Their private jokes and dumb arguments? More than memories, Josh, then 24, wished for the crude procedure to save whatever part of her brain gave rise to her dry, generous humor, compelled her to greet every cat she saw with a high-pitched "helllooo," and inspired her to write him poems.

"I just think it's worth trying to preserve Kim," Josh said.

What Is Cryonics?

It may sound crazy, but a handful of people around the world every year choose cryonics over burial. That means they decide to freeze their bodies upon death, in the hope that decades or centuries from now they could be revived. Others, like Kim, prefer to preserve only their heads, so that, in the future, the brain's billions of interconnected neurons could be digitally scanned and converted into computer code. If that code is one day "uploaded" to a robotic or virtual body, the hope is that a person's mind could be brought back to life. (That's because it's widely believed that a brain's network of neurons encodes our unique memories and learned behaviors--and, some argue, makes us who we are.)

Once the stuff of science fiction, the idea of brain preservation is today taken seriously by some neuroscientists, who believe it may be possible one day for our minds to continue after death--in a computer or some other kind of simulation. To make this happen, it's key to preserve a person's brain correctly after death.

Cryonics tries to do this by storing the brain at very low temperatures in liquid nitrogen gas. Even when that process goes well, though, it almost certainly damages some of the billions of fragile connections in a human brain. The second step is to scan those connections sometime in the future and map them using computers to create a digital reproduction of the brain.

The latest advances in science seem...