DEEP DIVE

Death seems “kind of arbitrary”: Scientists want to upload the brain so we can live forever

Is immortality possible by digitally scanning the brain? Dr. Zeleznikow-Johnston believes so but some are skeptical

By Matthew Rozsa

Staff Writer

Published December 16, 2024 5:30AM (EST)

Digital Brain Upload (Getty Images/Yuichiro Chino)
Digital Brain Upload (Getty Images/Yuichiro Chino)

Humans have yearned for immortality for as long as we‘ve understood our fragile permanence. But while dodging the Grim Reaper was once relegated to the realm of religious myth, now technology is attempting to find the cure for death. Most popular is the idea of cryopreservation — that is, any process which preserves biological tissues by storing them at extremely cold temperatures — which can be traced back to a 1931 science fiction novel, “The Jameson Satellite” by Neil R. Jones. The first in a series of adventure tales about the titular Professor Jameson, the story includes a detailed description of the professor freezing his brain and sending it into space, where it is eventually revived and installed into a mechanical body.

Jones’ ideas were so provocative, they inspired American academic Robert Ettinger to write a 1962 non-fiction book, “The Prospect of Immortality.” In 1976, Ettinger founded the Cryonics Institute, a nonprofit that freezes both humans and pets in the hope of someday reviving them, and the cryopreservation movement was born.

Dr. Ariel Zeleznikow-Johnston hopes to pick up the movement where Jones left off, albeit with the significant twist that his version does not require freezing. A research fellow at Melbourne’s Monash University, Zeleznikow-Johnston wrote the new book, "The Future Loves You: How and Why We Should Abolish Death," which makes the case that cryopreservation is possible and should be more widely available. Rejecting the popular notion that death endows life with meaning as “palliative philosophy,” Zeleznikow-Johnston’s book instead argues a human’s connectome — a high-resolution map of all their brain connections — could be theoretically recorded perfectly before they die.

Once that happens, that same internal brain activity could be recreated through high-powered computers, while a new brain is grown in a vat via stem cells or some combination of the two. As such, Zeleznikow-Johnston is proposing a spiritual descendant to the cryonics movement (which he dismisses as “unscientific” and “unsubstantiated”), one where the focus is not on preserving tissues but on the “data,” so to speak, of our distinct connectomes.

"We have very strong evidence that the static structure of the neurons is enough to hold onto someone's memories and personality."

“Within this science fiction is a kernel of truth: with sufficient understanding of how the brain enables a person to be who they are, it might be possible to place a dying individual in a state from which they could one day be revived,” Zeleznikow-Johnston writes in his book. From there he explores how the current state of neuroscientific recording and tissue preservation is such that, while his dream is currently not possible, technologies like chemical vitrification (a process for hardening the outer eggs of embryos, similar to how glass is hardened) enable us to preserve a person’s brain well enough that the connectome could be preserved.

Salon reached out to both Zeleznikow-Johnston and to a group of scientists and philosophers who, though unable to read his just released book , were made familiar with its basic premise. One of them — Dr. Jason D. Shepherd, an associate professor of neurobiology at the University of Utah School of Medicine — was skeptical that it is feasible to recreate an individual’s unique connectome.


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“Even if you could download the information that a brain holds, the trillions of synaptic connections unique to each brain ... Those synapses are constantly changing,” Shepherd said. “Downloading would only catch a snapshot in time.” He also argued that too many scientists take for granted that consciousness can exist without a body, which Shepherd doubts.

“We neuroscientists have long ignored the brain-body axis but recently we have discovered that there is constant cellular and molecular communication between the body and the brain that ultimately contributes to our sense of self,” Shepherd explained.

In response to these arguments, Zeleznikow-Johnston told Salon that “an actively conscious individual, like you or I right now, has constantly changing dynamic properties of their synapses, where the neurons are electrically active and there is ion flow going from one neuron into another, chemical transmission, all sorts of changing dynamic properties.”

Yet even though this is the case, “we have very strong evidence that the static structure of the neurons is enough to hold onto someone's memories and personality and that sort of stuff,” Zeleznikow-Johnston said. “And we know that not in a weird science fiction, speculative way, because we have good data already to suggest that that's the case.”

"It's still two beings, two conscious entities, not one."

For example, Zeleznikow-Johnston pointed out that hospitals already widely use deep hypothermic circulatory arrest, or induced hypothermia. By cooling patients down to roughly 18º C (64º F), doctors can stop heart and brain activity to provide surgeons with a 45 to 60 minute operating window. The patients who are revived from this process keep their long-term memories, although they lose some working memories.

To David Skrbina, a philosopher and author of the books "Panpsychism in the West" and "The Metaphysics of Technology,” there is a much deeper flaw in Zeleznikow-Johnston’s hypothesis: It misunderstands the very nature of consciousness.

“Is my connection pattern equal to ‘me?’” Skrbina asked. “And if it continues to interact with the world, to change and to learn, is that ‘me’ that is changing?” Skrbina compared Zeleznikow-Johnston’s theoretical scenario as analogous to someone creating a clone with their exact memories.

“He would surely walk and talk like me!” Skrbina said. “He might even be able to fool family and friends. But still, there would be ‘me’ and ‘him.’ It's still two beings, two conscious entities, not one.”

Luke Roelofs, a philosopher of mind at NYU's Centre for Mind, Brain and Consciousness, also argued that the ideas in Zeleznikow-Johnston’s book are too cavalier in defining consciousness.

“It’s a generic term for a certain property we all share — I’m conscious, you’re conscious, and maybe years in the future a preserved brain, or an AI system, or a digital upload, will be conscious,” Roelofs said. “But people also use it as a catch-all, but talking about ‘my consciousness’ and ‘your consciousness’ as two distinct things. Thinking about immortality, the question is whether the consciousness that might be created in my cryogenically preserved brain in the future would be my consciousness, or a new consciousness that merely resembled mine.”

To Skrbina, the solution to these intractable problems defining consciousness is through a philosophical concept known as panpsychism. Panpsychists believe that all forms of matter, however small, contain elements of consciousness, and that life as many define it is simply made up of extremely complex forms of consciousness created via organic chemistry. Of course, because consciousness is perceived by panpsychists to be universal, the term “consciousness” itself becomes somewhat misleading.

“As a panpsychist, I prefer not to use that term, which, in addition to being vague, is also quite anthropocentric,” Skrbina said. “I prefer more generic descriptions of mentality: experientiality, subjectivity, intentionality and qualitative feeling. We have a hard time extending consciousness to other beings, especially to the ‘lower’ animals (whatever those might be), plants or inorganic things. But it seems easier to talk about experientiality or subjectivity, or even will, in all things.”

"We believe contemporary structural brain preservation methods have a non-negligible chance of allowing successful restoration in the future."

Addressing the philosophers’ observations about consciousness, Zeleznikow-Johnston acknowledged that there is “not a good consensus on how consciousness comes about or even often exactly how to go about defining consciousness. But the most common working definition used by neuroscientists and philosophers is that for something to be conscious means that it feels like something to be that thing.”

However, Zeleznikow-Johnston disagrees with that definition because he feels it is a “first person subjective definition” of consciousness, rather than one sufficiently detached to be ascertainable by a theoretical third party. Instead, he subscribes to a different philosophical school.

“One very common theory amongst philosophers and neuroscientists is functionalism, the idea that all that really matters is the function, not whether something is made of biology or silicon or anything else,” Zeleznikow-Johnston said. “A mind upload would probably be conscious in the same way that a natural biological human is.” For similar reasons, Zeleznikow-Johnston rejects panpsychism.

“I'm not the most sympathetic to panpsychism in its broadest sense of even electrons having some simple level of consciousness because of the combination problem, which is how electrons, molecules, atoms and small things — with their little proto-consciousness or small elements — come together to produce a unified consciousness in a larger entity,” Zeleznikow-Johnston said. “If all of the bits in my head have their own unique little bits of consciousness, it's unclear how they combine into my unified sense of conscious experience.”

Hedda Hassel Mørch, a philosopher and associate professor at Inland Norway University of Applied Sciences, argued that all of the parties in this conversation need to distinguish between what they mean by consciousness and self. At the same time, they need to understand that at least some of these debates may be more intellectual than practical in their consequences.

“Most philosophical theories of consciousness hold that our consciousness correlates with the brain (they just disagree about how and why), such that if it were possible to revive a cryopreserved brain then consciousness would come back,” Mørch said, including panpsychism. “If a cryopreserved brain is revived, and put back into more or less the exact same physical state as before preservation, it seems natural given panpsychism that the consciousness of its particles or other constituents would ‘recombine’ such that more or less the exact same kind of complex consciousness would return.”

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Regardless of whether his ideas are technically possible, Zeleznikow-Johnston believes they are exciting because at the very least they strive toward the desirable end of prolonging and enriching human life. A recent study in Frontiers in Medical Technology explored several potential strategies for preserving structural information in the brain after death, including traditional cryopreservation.

“We believe contemporary structural brain preservation methods have a non-negligible chance of allowing successful restoration in the future and that this deserves serious research efforts by the scientific community,” the authors wrote. “Research in this area will potentially have spillover benefits to other fields, including improvements in methods to study brain disorders and neural ischemia, improvements in techniques for organ banking, and enabling human space exploration.”

When asked about the possibility that eliminating death will render life less important, Zeleznikow-Johnston strenuously disagrees.

“Why do we get the 80 years that we currently have, as opposed to the one year that a mouse gets, or the 200 to 250 years that a whale or tortoise gets?” Zeleznikow-Johnston asked. “If our lives are given meaning by 80 years, would they be more meaningful if we live 60 years or substantially less meaningful if we lived 150 years? It seems kind of arbitrary once you start looking at the evolutionary biology of why we live the lives we do, that that should be the limit that we should be accepting.”


By Matthew Rozsa

Matthew Rozsa is a staff writer at Salon. He received a Master's Degree in History from Rutgers-Newark in 2012 and was awarded a science journalism fellowship from the Metcalf Institute in 2022.

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Death Deep Dive Immortality Neuroscience Science Uploading Brains