This neuroscientist wants you to live forever. Here’s how

Dr Ariel Zeleznikow-Johnston wants to live forever.

Not just him. He wants you to live forever, too. Or at least he wants you to have the option.

We’ve met at Peruvian restaurant Pastuso to talk about immortality and conquering death.

Zeleznikow-Johnston laughs when I ask him how he got into the immortality business. “No promises of immortality,” he says, taking a sip of an excellent complimentary pisco sour. “It’s more just trying to extend life.” Extend it how long? Potentially forever.

Zeleznikow-Johnston is the author of The Future Loves You: How and Why We Should Abolish Death, and he’s a leading voice in the field of cryonics. Let’s be clear: we are talking Walt Disney brain-in-a-jar, frozen people, suspended-animation stuff.

But Zeleznikow-Johnston is not some guru with crystals and a couple of hundred hectares of underused desert, nor is he a Silicon Valley tech bro taking blood from his son and micro-dosing off-label organ transplant meds. He’s a research fellow working in the Monash neuroscience consciousness laboratory and has a doctorate of neuroscience from Melbourne University. And he thinks that not only is it theoretically possible to preserve consciousness indefinitely, the technology to do it is basically ready now.

Sharing plates are the norm at Pastuso, and we decide to start with Pastuso’s signature dish, the kingfish ceviche, cured with lime and swimming in a bright orange sauce spiked with smoky rocoto peppers and topped with crunchy plantain chips.

The fish special today is swordfish smothered in herbs, and we decide to pair it with twice-cooked potatoes and char-grilled broccoli and green beans. These last come with smoked cultured butter and yoghurt, whose creaminess offsets the snap of the greens.

Zeleznikow-Johnston’s book is written in a breezy, chatty tone, and is accessible to a lay audience as much as a scientific one. In it, he lays out the case as to why people not only can, but should live forever. Zeleznikow-Johnston says there is very good evidence that memories, consciousness and even personality leave a physical and permanent mark on the brain, meaning that if you can preserve the physical tissue, you can preserve a person’s self after death.

“You can take a mouse, put it in a scary situation, record the neurons that are active at that time, then later on, in a totally neutral environment, turn those neurons back on again, and the mouse freezes as though it’s recalling the scary experience.

“And there’s even been subsequent experiments where they would teach a mouse to do something like run along a high rope and record the neurons that were active, then teach it to hold onto a rotating rod, sort of thing. And it gets better and better, so you record which neurons are active for that and then selectively erase one or the other memory while leaving the other one intact.”

He says the memories and knowledge make a physical mark on the mouse’s brain.

“It’s demonstrating that although we don’t fully understand how the circuitry works, we can at least show that it’s this specific structure and connections that encode this specific memory.”

If that’s true for a mouse, there’s no reason to think it isn’t for a human, says Zeleznikow-Johnston. So if a brain can be preserved, he says, a person can be preserved. And the preservation part is within current technical capabilities.

In fact, scientists and doctors do it all the time.

“These days we routinely preserve eggs, embryos, those sorts of things – for years, sometimes,” he says. “So it makes sense to think: could you do that to a person? The issue with the techniques as historically practised, though, is they didn’t necessarily provide very good preservation of like brain and body structure. So the earliest techniques people tried were just straight freezing, just like submerging people in essentially cold temperatures and then liquid nitrogen. The issue with that is you get ice formation, and the ice, when it forms crystals, it breaks cells, punctures organs, does a whole bunch of damage to people.”

Here’s the bad news for early adopters of cryonics (which, by the way, does not include old Walt; that’s a myth): those ice crystals and freezing techniques have led to an awful lot of decay.

“If you look at the brains of people who’ve historically been preserved by these cryonics organisations, you’ll see that their brains have shrivelled down by 50 per cent or so in size because it’s hard for these antifreeze chemicals to get into the brain, and then it dehydrates them in a way that’s not ideal.”

“Not ideal” is brain scientist for “they are probably never going to be successfully revived, but we can’t actually know because we don’t have the technology to try”.

And that is where the rub is now – Zeleznikow-Johnston says that with modern freezing techniques, a properly trained cryonic scientist with the necessary equipment can freeze a recently deceased person in such a way as will preserve them. In his ideal scenario, every hospital and hospice would be equipped with such a lab, and the procedure would be covered by Medicare. But what no one on Earth can currently do is thaw someone out. That doesn’t mean that in the future that technology won’t be possible, as things that were once thought to be magical are now commonplace.

He thinks that in the most likely scenario, that will not mean thawing out a dead body, reanimating it and that person goes on about their business as if they had never died.

“In the same way we have cochlear implants for people who lose their ability to hear and increasingly, brain implants for people who’ve had strokes or spinal cord injuries, I also think that in the long run, we will probably develop technology that can replace traditional human biology.”

I want to make sure he’s saying what I think he’s saying. I’ve only had the one pisco sour, but it’s good to check. “So you’re basically downloading the brain into a robot?”

“I do think there’s a reasonable chance something like that could be made to work because it seems to be the logical extension of today’s neural prosthetic technology,” he says.

“If you can make an artificial limb and you can connect it up to someone’s brain, just imagine taking that a little further and a little further and a little further, and eventually you’ve gotten yourself fully out of physical body.”

He knows how ‘brain downloaded into a robot’ comes across, but he has given the matter very real scientific thought. “It sounds weird and sci-fi, but I do think it’s the logical conclusion of how neuroscience has been developing.”

And he says it’s not as far away as you might think.

“What you have to do is preserve a brain well, then image it at really high resolution, and then convert that into some sort of digital model, and then get that to run. And check whether your model works properly.

“So for example, in October of last year, this was completed for a fruit fly brain, which has about 160,000 neurons and a quadrillion connections or so, and they were able to make a digital model of it. It was good enough that it replicated some of the behaviours of the fly. If you applied a sugar kind of stimulus to its digital neurons, it tried to stick out its proboscis.”

A human brain is obviously orders of magnitude more complicated than a fruit fly, but the concept of uploading an animal brain into a computer model has already been successfully proven. So Zeleznikow-Johnston has reason to believe this will be possible for people at some point in the future.

“But why would they?” I ask. “I don’t have any skills that they would want. Like, I don’t know anything they want to know.” Why would these scientifically advanced people of the future bother downloading my brain?

“I don’t think we would be useful, except in a museum or historical sense, in a direct, practical capacity. But I think it’s more my hope is that it would be out of concern and care and love – and professional ideal. So at the moment, if you go to the emergency department, they don’t check if you’re a valuable member of society before they give you treatment ... In the future, my hope is people would say, ‘look, the society we live in is pretty good, we’ve got a lot of wealth and resources these days. It’s as a result of our ancestors’ efforts that we’re able to live here’. In the same way that we get nice food, electricity, running water and we don’t all get diseases because of people from generations before us. That’s my hope.”

Assuming that the technology is now good enough to freeze people, that in the future it will be good enough to unfreeze them (or put their consciousnesses into a new vessel) and that the people in the future will be inclined to use that technology en masse to bring back their ancestors, the last question is: why would you want to?

And is there a limit to the amount of time people might want to live?

“I struggle to imagine there would ever come a day where I wouldn’t be like, I feel like going to lunch with my friends, or I like reading this new book, or there’s a fun project to work on, or I’d like to go travelling here or there.

“Maybe that’s not true. Maybe after 300 years, I’d be like, I’m so bored of every opportunity that is available. I know everything, I’ve been everywhere, I’ve done every experience. But it seems pretty unlikely to me, at least for a long while, that would be the case.”

Ariel Zeleznikow-Johnston will give a talk, How to Live Forever, at The Wheeler Centre on August 27; presented by Now or Never and The Wheeler Centre.