When we talk about death, we often say things along the lines of “it’s a fact of life,” but the view can be very different when you’re facing the real and imminent prospect of no longer existing. Given the chance, can we be so sure that we wouldn’t try anything for a little more time?
According to neuroscientist Dr Ariel Zeleznikow-Johnston, most of the general public tends to say they’d like 10 years more life than they’re statistically likely to get when asked “how long do you want to live?”, and it seems the hunger for more doesn’t diminish as time goes by.
There already exists at least one well-designed brain preservation procedure offering a credible possibility of indefinitely delaying death
Dr Ariel Zeleznikow-Johnston
“If you move beyond general surveys of relatively healthy people and you ask people who are at death’s door (those who are in hospices and are terminally ill with untreatable cancer, for example), around about 70 percent of people surveyed still report having a very strong will to live, even at death’s door,” he told IFLScience.
So, what if there was a way that we could postpone the seemingly inevitable by capturing the essence of who a person was, and storing it until future technologies enable us to bring them back? If we found a way to lock in someone’s way of thinking, their memories, and all the parts that make them unique, could we even postpone death indefinitely?
That’s a key theme in Zeleznikow-Johnston’s new book, The Future Loves You: How And Why We Should Abolish Death. Abolishing death is a radical idea that few were so eager to dive into during early conversations about the book – but since its release, his own survey has revealed that, actually, there are scientists out there who think the idea is worth attention.
That’s a substantial chunk of neuroscientists who think there’s a very real chance that it will work
Dr Ariel Zeleznikow-Johnston
“We ran a survey of what the neuroscientific community thinks about the possibility of preserving brains,” he said. “People’s views on ‘would it work’ were super variable. Some were like, ‘Yeah, I think I’m pretty confident this will work’. Some people were like, ‘Absolutely not’. But the median probability (the average probability people gave for being able to produce a whole brain emulation given current preservation techniques) was about 40 percent.”
“That’s a substantial chunk of neuroscientists who think there’s a very real chance that it will work, and my guess is actually that number will creep up over time as we get better at doing these brain implants, emulations, all these other things.”
So, what might that brain preservation look like? As Zeleznikow-Johnston writes in the book, “there already exists at least one well-designed brain preservation procedure offering a credible possibility of indefinitely delaying death,” and it all centers around the connectome.
What is a connectome?
A connectome is the idea that each of us has our unique set of connections between our brain cells
Dr Ariel Zeleznikow-Johnston
The connectome was first popularized by Sebastian Seung who gave a Ted Talk titled I Am My Connectome back in 2010. Since then, it’s been the subject of research seeking the neuronal indicators of aging, lifespan, development, and disease, but what exactly is it?
“A connectome is the idea that each of us has our unique set of connections between our brain cells, between our neurons, that encode our memories, our personality, and our unique traits compared to anyone else’s,” Zeleznikow-Johnston told IFLScience. “The aggregate of those together is called your connectome.”
The name was inspired by the complexity and uniqueness of the genome, and it seems fitting given The Future Loves You provides the dizzying statistic that “We would need the stars of 10,000 galaxies to equal the number of synapses that make up the connectome.”
Mapping the connectome
It’s a hell of a landscape to navigate, and we have yet to map the entire human connectome (though we have done it for fruit fly larvae), but scientists are trying, slice by slice. That’s because the technology needed to map to the correct degree of detail can’t penetrate deep organs, but by tackling thin sections of the brain we could feasibly take enough images to eventually stitch them back together and create an entire brain with the help of artificial intelligence.
If the mapping technology becomes available, that connectome could theoretically be retrieved from a brain as much as 36 hours after cardiac death, Zeleznikow-Johnston explained. That’s because the crucial synaptic connections we’re interested in remain intact for at least 15 minutes after death, and while 24 to 36 hours after death would be far from ideal, it’s possible the degradation could be minimal enough to still extract something meaningful.
Information-theoretic death
The idea of retrieving someone’s connectome from a dying body introduces a definition of death that deals with the brain as if it were code stuck inside a faulty computer: information-theoretic death. It considers the proverbial bucket to have been kicked when technology can no longer bring a person – their connectome – back from their body, in the same way that a ventilator can restore breathing, and ECMO can help cardiac function recover.
The question is, what is the absolute limit of when a person can’t be brought back
Dr Ariel Zeleznikow-Johnston
If a patient is declared brain dead, but we can still bring their connectome back, they may not have to be dead after all. There are already some mundane and extreme examples that see us temporarily shut down before being restored – is returning from death just the next step in medical advancements?
“If they’re asleep, it’s okay, they can come back,” he said. “If they’re under anaesthesia, it’s okay, they can come back. There’s even circumstances where people become hypothermic, where their brain activity completely stops. Everything seems to stop, but we see that we can warm them back up again and they restore it to consciousness. So, the question is, what is the absolute limit of when a person can’t be brought back, and that’s what some people term information-theoretic death.”
Digitizing a connectome
If we’re to capture the human connectome and find a way to digitize it, the theory goes that full brain emulation could one day enable us to bring people back even when their bodies are unliveable, which – by the definition of information-theoretic death – could be argued to be akin to a kind of immortality. So, how do you digitize a connectome? Listen to the excerpt from The Future Loves You: How And Why We Should Abolish Death below to find out.
Hungry for more? Read an excerpt and interview with Dr Ariel Zeleznikow-Johnston in the December issue of CURIOUS, or keep an eye out for our March issue’s We Have Questions in which we’ll be diving into the sticky subjects of cryonics, head transplants, and what defines a person.