In 2018, the Vancouver-based start-up Nectome made headlines when Sam Altman paid a $10,000 deposit to hitch the ready checklist for a service that it nonetheless doesn’t present: he desires to “freeze” his mind. Particularly, he desires to protect his mind minutes after his demise in order that it might finally be digitised to render him immortal. Altman, now CEO of the AI firm behind ChatGPT, grew to become the twenty fifth individual to hitch the ready checklist. “I assume my mind can be uploaded to the cloud,” he advised MIT Know-how Evaluation.
The concept of preserving an individual’s mind to revive it sooner or later sooner or later feels like science fiction. Preserving a human mind in a such a manner that it retains its microscopic construction poses main technological challenges. Subsequent levels of the method – ought to we ever attain them – pose even larger conundrums, and lift philosophical questions concerning the nature of consciousness.
But, in line with a current survey performed by Ariel Zeleznikow-Johnston, a neuroscientist at Monash College in Melbourne, Australia, and colleagues, a couple of quarter of physicians in the USA “discovered preservation considerably or very believable for enabling future revival”. Requested to estimate the chance that, below the precise situations, the method “may retain ample neural info for future revival”, the median response from the greater than 300 medical doctors surveyed was 25.5 per cent.
Analysis research printed earlier this 12 months describe what some within the discipline are calling main advances in mind cryopreservation know-how, and Nectome is now certainly one of about half a dozen corporations providing mind or complete physique cryopreservation providers. Ought to we be taking this business significantly, together with its moral implications?
*
The search for immortality is as outdated as time itself, however cryonics – the observe of freezing useless our bodies or brains – was popularised by a 1967 ebook entitled The Prospect of Immortality. Its creator, the physicist Robert Ettinger, based the Cryonics Institute in 1976, which pioneered the method and continues to supply cryopreservation for $28,000-$45,000. The corporate now has greater than 250 “sufferers” in cryostasis at its facility in Clinton Township, Michigan.
The cryonics process includes eradicating blood from the affected person’s physique and changing it with an answer of cryoprotectant chemical compounds. The physique is then cooled all the way down to -196°C with liquid nitrogen. The cryoprotectants act like organic antifreeze, stopping the formation of ice crystals throughout cooling. As an alternative, this causes the water within the physique to solidify right into a glass-like state, in a course of known as vitrification.
The Cryonics Institute claims that its “sufferers” can stay in cryostasis indefinitely, on the premise that “medical doctors of the long run … have perfected methods for repairing and restoring the human physique… [and can] efficiently revive individuals who have been thought-about deceased by at present’s requirements”.
However maybe we don’t must discover ways to revive our bodily brains, as a way to give them a “second life”. Mind cryopreservation researchers at present are inclined to have a special purpose in thoughts. Fairly than making an attempt to revive preserved at brains, they favour mind emulation, which includes making a high-resolution digital reproduction of an entire human mind. The concept is {that a} reproduction based mostly on an individual’s detailed mind connectome knowledge may recreate their reminiscences – and even, maybe, turn out to be acutely aware.
Nectome is focusing its efforts on growing “a course of … to completely protect each neuron and synapse of the mind… [to] preserve its high quality, all the way down to the nanoscale, for 100 years or extra”. However somewhat than revive the mind itself, Nectome’s founder claims that it’ll finally be doable to digitise its construction, and the neural info saved inside it, then add the information to a supercomputer, to emulate the person’s thoughts and consciousness.
*
The examine and mapping of the mind is known as connectomics. It’s a comparatively current neuroscientific discipline that goals to comprehensively map the pathways, circuits and synaptic connections within the nervous system. It requires taking a look at ultra-thin slices of mind tissue below highly effective microscopes as a way to reconstruct the fantastic construction of the cell our bodies, fibres and synapses.
This strategy is usually mixed with neuronal “tracing” strategies that use genetic engineering to colourise particular person cells in order that their fibres and connections could be delineated extra simply. At a bigger scale, subtle imaging methods are used to visualise the bundles of nerve fibres that function long-range connections between distant mind areas and examine how totally different mind areas kind their networks.
Connectomics analysis is extraordinarily laborious and produces monumental knowledge units, which aren’t all the time suitable with one another. The primary organism to have its complete nervous system mapped was the millimetre-long worm C. elegans in 1984. This tiny creature’s nervous system incorporates simply 304 neurons; but, with solely electron microscopy at his disposal, it took biologist Sydney Brenner 10 years to map their structure and connections.
Quick-forward 40 years, to October 2024. The FlyWire Consortium reported that that they had mapped the complete connectome of the fruit fly D. melanogaster. The fruit fly has a mind the scale of a pinhead, however even with extra subtle strategies, it nonetheless took this very massive workforce, unfold over 127 tutorial establishments world wide, six years to map the connectome.
The human mind shouldn’t be solely vastly greater than that of a fruit fly, but in addition vastly extra complicated. A 2024 examine led by researchers at Harvard used electron microscopy to picture and reconstruct a cubic millimetre-sized piece of human mind tissue that had been faraway from a affected person throughout surgical procedure for epilepsy. The researchers lower the tissue into greater than 5,000 sections after which imaged each, yielding 1,400 terabytes of information.
They then generated a 3D reconstruction, revealing simply how dense and complicated this tiny chunk was: it contained some 57,000 neurons and glial (or non-neuronal) cells. Your entire human mind incorporates roughly 80 billion neurons and a minimum of twice as many glial cells, which between them kind a whole lot of trillions of synapses.
*
If the mind might be preserved, then maybe the data might be extracted sooner or later sooner or later. However preserving the fantastic construction of this extraordinarily delicate and complicated tissue isn’t any imply feat. Merely “fixing” a mind to forestall chemical modifications after which freezing it results in the formation of ice crystals that distort and injury the fantastic construction of the fragile tissue. Researchers at Nectome, the Cryonics Institute and different corporations use a way known as aldehyde-stabilised cryopreservation as a way to forestall this.
Developed by Aurelia Tune and Greg Fahy, this includes passing two options by means of the mind – first an answer of aldehydes, after which a highly-concentrated resolution of cryoprotectant chemical compounds – to forestall ice formation throughout cooling and switch the complete system “right into a stable glass”, as they wrote of their 2015 paper. They added that it “guarantees to be a robust new method within the quest of connectomics researchers to unravel the mysteries of the thoughts”.
Tune went on to co-found Nectome, which, in line with its web site, is “devoted to advancing the science of reminiscence preservation”, in order that it might “protect individuals inside minutes after authorized demise as a way to protect the physique and mind to a particularly excessive degree of high quality”. The corporate obtained a $960,000 federal grant from the US Nationwide Institute of Psychological Well being, an extra $120,000 from the know-how start-up accelerator Y Combinator, and was additionally awarded an $80,000 prize by the Mind Preservation Basis.
Nectome rapidly grew to become mired in controversy, nonetheless, when it introduced plans to start the method on anaesthetized terminally ailing sufferers, passing the cryopreservant chemical compounds by means of their mind whereas they’re dying. Subsequently, MIT neuroscientist Ed Boyden stopped collaborating with Nectome, and the college terminated its subcontract with the corporate.
Tune’s newest examine makes use of pig brains, whose anatomy and vasculature carefully resemble these of people, to indicate that her new protocol “leads to connectomically traceable complete brains” that might be saved economically, and preserve stability, “even for hundreds of years”. A draft paper was printed in March however has not but been peer reviewed; it concludes that the brand new protocol “is suitable with human mind preservation after physician-assisted demise, offered that the blood washout is initiated lower than about 14 min after cardiac arrest”. In sensible phrases,this implies somebody from Nectome must be onhand whereas the person is euthanised, as a way to start the cryopreservation protocol inside minutes of demise.
At across the identical time this examine got here out, Fahy and his colleagues printed one other draft paper demonstrating that the construction of complete rabbit brains “could be preserved by vitrification with out prior aldehyde fixation”, by utilizing a cryoprotectant known as M22. This may additional cut back injury to the mind tissue. The researchers then investigated the results on tissue biopsies from the human cerebral cortex, displaying that these had “no indicators of ice crystal injury”. The method triggered “mind shrinkage ample to distort and obscure neuroanatomical particulars” – however this was, they are saying, reversed upon rehydration.
The human mind tissue samples used on this examine got here from L. Stephen Cole, a gerontology researcher at UCLA’s David Geffen Faculty of Drugs with a powerful curiosity incryonics. Cole died of pancreatic most cancers in 2014 and had requested Fahy to carry out the process on his mind. Quickly after his demise, Cole’s physique was transported to the Alcor Life Extension Basis in Scottsdale, Arizona, whereupon his mind was eliminated and saved at -146 °C.
*
What concerning the future prospect of reviving these brains? There was some progress in displaying the potential for mind revivification, though none on human tissue. A examine printed this 12 months by researchers in Germany exhibits that slices of rat mind tissue can recuperate their electrical exercise after being rendered utterly motionless in cryogenic glass by vitrification. Nonetheless, this work, printed within the Proceedings of the Nationwide Academy of Sciences, solely demonstrates short-term restoration – the tissue underwent deterioration after 10-15 hours.
Lead creator Alexander German nonetheless believes this was a major step. He mentioned that the examine “confirmed intact synapses and dendrites … mitochondrial exercise … neurons firing and … synapses speaking”. He additionally mentioned they managed to recuperate “the mobile mechanism for studying and reminiscence”. In different phrases, the tissue gave the impression to be totally, or a minimum of principally, purposeful. “We didn’t reanimate or revive a acutely aware mind,” he conceded, however didn’t rule out the opportunity of mind operate restoration “within the distant future”.
After which there may be the digital route, which comes with its personal challenges. In 2008, Anders Sandberg and Nick Bostrom of the Way forward for Humanity Institute at Oxford printed a report entitled “Entire Mind Emulation: A Roadmap”, which incorporates probably the most detailed, and most generally cited, estimate of how a lot computing energy could be wanted to construct and run a simulation of the human mind.
Based on Sandberg and Bostrom, a low-resolution mannequin of a mind that simulates neurons as easy “onoff” spiking models, and synapses as “weighted” connections with totally different strengths, would require between one petaflop and one exaflop of computing energy. For comparability, the world’s quickest supercomputer – at China’s Nationwide Supercomputing Heart – has achieved slightly below 2.2 exaflops. A extra detailed mannequin that includes gene expression, protein–protein interactions and different molecular degree processes which can be in all probability necessary for neuronal operate would doubtless require a minimum of 10 million exaflops of computing energy.
Storing all this knowledge would require a minimum of an exabyte (one billion gigabytes), or presumably two or three. Though it’s inconceivable to rank AI knowledge centres on the premise of their storage capability, one contender for the “largest” is xAI’s Colossus supercomputer in Memphis, Tennessee, which has an estimated 0.5 exabytes of complete storage for coaching its algorithm, alongside some 200,000 graphics processing models.
*
Even when the fast tempo of technological development and the function of synthetic intelligence in accelerating scientific discovery are factored in, complete mind emulation remains to be a great distance off. Based on one other survey by the neuroscientist Zeleznikow-Johnston: “When predicting the long run feasibility of complete mind emulation, the median participant estimated that this is able to be achieved for C. elegans [the millimetre-long worm] round 2045, mice round 2065, and people round 2125.”
Others imagine that it might merely not be achievable. The opportunity of mind emulation rests on a number of assumptions. First, it’s assumed that studying happens by the modification of synaptic connections, that reminiscences are saved in sparsely distributed networks of neurons and their synapses, and that retrieval of a reminiscence includes the “reactivation” of the neuronal community during which it’s saved. There’s sturdy proof to assist these claims. There’s, nonetheless, a lot that we nonetheless have no idea concerning the neural foundation of studying and reminiscence. Neurons and synapses are virtually actually components of a much bigger image that we nonetheless don’t see.
That the reproduction may turn out to be acutely aware appears much more far-fetched. Neuroscientists are nonetheless struggling to outline consciousness, not to mention perceive its underlying mind mechanisms. And whereas there’s little doubt that the mind performs an necessary function in producing our acutely aware experiences, it’s removed from clear that the mind is ample for human consciousness. The mind, physique and atmosphere kind a posh, dynamic system, and consciousness emerges from the interactions between them.
All issues thought-about, Sam Altman’s assumption that his “mind can be uploaded to the cloud” might be unrealistic. And if mapping his complete connectome then importing it to a supercomputer does turn out to be doable sooner or later sooner or later, it could even be a particularly egocentric and immoral factor to do. AI knowledge centres and different supercomputers devour huge quantities of power and water, so the endeavour would divert these assets from extra necessary makes use of, akin to sustaining human life.
As of 2026, slightly below 700 individuals have been cryopreserved. This quantity is growing, though very slowly, with extra individuals preserving solely their brains, not their our bodies, in all probability due to the decrease value of the process. Cryopreservation serves as a techno-religion that provides the hope of transcending biology to realize a type of immortality. The concept is gaining recognition, with membership of cryonics organisations additionally steadily growing.
Thoughts importing will virtually actually be nothing greater than a transhumanist fantasy, and even when the science does take us nearer, there are moral quandaries concerned. But there could also be some positives, and we’re sure to study extra about how our brains operate alongside the way in which.
