Technological Advances in Cryonics: What’s Next?

In the history of cryonics we can identify a number of major technological developments: the introduction of cryoprotectants to reduce ice formation, the use of mechanical chest compression devices to restore brain perfusion and accelerate cooling, comprehensive multi-modal medications protocols to mitigate warm ischemia and favor good cryoprotective perfusion, remote blood washout with an organ preservation solution to protect against cold ischemia, closed-circuit cryoprotective perfusion to reduce osmotic damage, and, of course, the introduction of vitrification agents to eliminate ice formation altogether.

What are the kinds of major technological developments that we can expect in cryonics in the foreseeable future? When we talk about technological progress we should distinguish among advances in medical science that simply require implementation in cryonics, advances in medical science that require various degrees of modification to be used in cryonics, and technological developments that are conceived and developed within cryonics. These distinctions are important to recognize because they can tell us whether new advances “simply” require acquiring these technologies or whether an ambitious research and development program needs to be launched to validate, develop, and introduce these technologies.

The three most important future technological advances that I can foresee are:

1. Liquid ventilation (cyclic cold lung lavage). Currently there are two basic modes of cooling in cryonics: (a) external cooling in an ice bath and (b) internal cooling with an organ preservation solution. Considering the harmful effects of warm ischemia on the structure of the brain and distribution of the vitrification agent, it is very important to introduce a rapid method of initial cooling that does not require surgery and can approximate the rates of internal cooling. The most potent candidate here is liquid ventilation in which a cold perfluorocarbon is pumped in and out of the lungs to accelerate cooling of the patient.

2. Intermediate temperature storage (ITS). As vitrification eliminates ice formation, fracturing remains the only mechanical form of injury in contemporary cryonics. The most obvious solution is to store patients below the glass transition temperature ((‑123°C for the M22 vitrification solution) but not so low as to induce fracturing. Functional neuro ITS units have been built and detailed designs for whole body ITS units have been developed. Concerns that have not been fully addressed yet include optimal storage temperature and cost. The most pressing practical question at this point is whether fracture-free storage may be possible at liquid nitrogen temperatures if ischemia-induced ice formation is eliminated and a proper cooling protocol is used. Also, would it possible to eliminate the need for ITS altogether if a cold gas is circulated through the patient’s circulatory system instead?

3. Opening the blood-brain barrier. It has been well established that under good conditions loading of the vitrification agent produces severe dehydration of the brain. While dehydration may not substantially alter brain structure, it is a problem in terms of maintaining viability of the brain and producing good electron micrographs. We now know of a number of agents that can modify the blood-brain barrier to allow cryoprotective perfusion without severe dehydration. Current concerns include whether such agents produce edema in other parts of the body, what the optimum protocol and dosage should be for humans, and whether the use of such agents reduces or favors ice formation in ischemic brains.

Other conceivable advantages that can improve cryonics include lower toxicity vitrification agents, drugs that can substantially reduce metabolism in the brain, and integration of brain imaging and cryoprotectant perfusion.

Originally published as a column in Cryonics magazine, April, 2014

Low Cost Cryonics

Over the years some cryonics proponents have expressed interest and support for offering an inexpensive form of cryonics. Before discussing what such a form of cryonics might entail I first would like to briefly address the question of whether the idea of low cost cryonics is a solution to a non-existent problem. After all, for low cost cryonics to make sense, there must be a substantial number of people being priced out of cryonics arrangements who would make arrangements if it were more affordable. For this to occur a person must not only not be able to afford Alcor’s services but also not be able to afford the Cryonics Institute’s either. As far as I am aware, this problem is mostly confined to people who are basically uninsurable due to a medical condition or advanced age, or who wish to cryopreserve someone else where funding is insufficient.

In some cases, however, people who have found themselves priced out of cryonics arrangements have been the beneficiary of fund raising campaigns within the cryonics community. While it may not be possible to provide funding for all such cases, this development does raise the question of how many people who had a strong public desire to be cryopreserved did not get their wishes honored. The major reason to advocate low cost cryonics is to bring the service within the reach of more people. Thus it is important to understand how many people are actually excluded from being cryopreserved due to financial challenges. If access to cryonics is mostly a non-issue one might argue that strategies to simply aim at more people making cryonics arrangements can be more effective than offering lower priced options.

There are roughly three areas where cost savings can be realized in cryonics: (a) long term care costs, (b) cryoprotection, and (c) standby and stabilization. It is not possible to do justice to all the potential cost savings in these areas so let me briefly discuss the major themes.

While it is reasonable to assume that some long term care costs can be reduced by reducing expenses associated with running a cryonics organization (staff, administrative costs, rent) the bulk of long-term care expenses arise from the need to keep patients in cryopreservation until resuscitation efforts will be possible. If there is one thing we have learned since the early days of cryonics it is that it is not wise to compromise on demanding pre-payment (life insurance or cash) or to use wildly optimistic growth assumptions for these funds. A pay-as-you-go system would not just subject many patients to premature thawing but also endanger the reputation of the cryonics field as a whole.

This mostly leaves cryoprotection and standby services as potential cost saving measures. Clearly, offering standby and stabilization without subsequent cryoprotection would be an incoherent approach because attempts to preserve the viability of the brain would be followed by straight freezing. Offering sophisticated cryoprotection procedures without standby is not particularly logical either because optimal cryopreservation requires rapid stabilization and cooling after clinical death. To really realize substantial cost savings a cryonics organization would need to exclude both standby and cryoprotection from its protocol and focus on the isolated brain. Is it responsible for a cryonics organization to offer such a form of low cost cryonics? It is hard to answer this question because it is difficult to predict how much damage is still compatible with inferring the original state of the brain. One research program, however, that could give us preliminary answers to such questions is reconstructive connectomics. We can model these low cost cryonics protocols and then see if we can recognize or reconstruct the original structure of the brain using either conventional electron microscopy or more recent 3D brain mapping technologies. If this project provides reasons for optimism there is a strong ethical argument for an organization to offer this service.

In short, the most credible realization of “low cost cryonics” would entail a financially conservative cryonics organization that offers secure, isolated-brain cryopreservation without standby and without the state-of-the-art
cryoprotection now done at Alcor with a trained team, though a less training-intensive, inexpensive, method of cryoprotection (immersion of the brain in cryoprotectant after chemical fixation) might still be possible.

Originally published as a column in Cryonics magazine, March, 2014

Forever Lost? The First Cryonics Brain Repair Paper

For more than a year now I have been trying to locate Jerome B. White’s paper “Viral Induced Repair of Damaged Neurons with Preservation of Long Term Information Content.” This paper is referred to in a number of books and articles, including Robert Ettinger’s Man into Superman (1972), Eric Drexler’s Engines of Creation, and Mike Darwin’s biological repair proposal in his article The Anabolocyte (1977). Despite being recognized as the first presentation about repair of the brain of cryonics patients, I am not aware of any actual quotes or discussion of the paper, raising the question of how many authors who have referenced the paper have actually read it. The best I have been able to find is what amounts to the complete abstract of the paper in Robert Ettinger’s Man into Superman:

“An organic cell is a self repairing automaton, but if environmental interference exceeds a certain limit, damage will become total. Freezing can be used to halt progressive damage along with all metabolism, but means are required to restore or augment the cellular genetic control program, or enrich the environment to enhance repair ability. It has been proposed that appropriate genetic information be introduced by means of artificially constructed virus particles into a congenitally defective cell for remedy; similar means may be used for the more general case of repair. Progress has been made in many relevant areas. The repair program must use means such as protein synthesis and metabolic pathways to diagnose and repair any damage. Applied to brain neurons, this might destroy long term information content, which appears to be stored in molecular form, often suggested to be in a feedback cycle involving mRNA and protein. This information can be preserved by specifying that the repair program incorporate appropriate RNA tapes into itself upon entry and release them on termination of repair.”

Jerome B. White’s paper was presented at the Second National Cryonics Conference in Ann Arbor, Michigan, in 1969. Unfortunately, only the proceedings of the First Annual Cryonics Conference in 1968 have been made available as a book. We can state with reasonable certainty, though, that White spoke on this topic at the second conference because Saul Kent briefly mentions his presentation in a review of the conference for Cryonics Reports, April-May 1969. Even more intriguing, the reference for this paper in Man into Superman includes “reprints available [emphasis added] from the Cryonics Society of Michigan,” which provides evidence that this presentation was either transcribed or an actual paper was prepared prior to or after the conference. Notwithstanding this encouraging point, I have not been able to locate this paper so far, despite asking individuals such as Michael Darwin, Michael Perry, Stephen Bridge, and Catherine Donaldson. Could it be possible that a paper was produced and distributed on a small scale but no copies of the paper have survived? This would be a tragedy, especially in light of the fact that it was the first proposal for a cell repair machine to resuscitate cryonics patients.

One person we cannot consult is Jerome Butler White (b. 1938) himself. The “good” news is that Mr. White has not passed away but, after a struggle with AIDS, was cryopreserved in 1994 by the American Cryonics Society (ACS) in collaboration with BioPreservation. (He is now stored at the Cryonics Institute.) Some of his other presentations include “The Technology of Cryonic Suspension,” Cryonics Conference and Scientific Congress, San Francisco, 1971, and “Heat Flow in the Human Patient,” Lake Tahoe Life Extension Festival, 1985. In the internet age it is hard to imagine that any information can be lost forever but we cannot rule out here that only a few individuals who have heard this presentation in 1969 are still alive today (some who have made cryonics arrangements) and that all physical copies may have been (irretrievably) lost. If that is the case, the text of this first paper on viral cell repair of cryonics patients will never be known and we can only speculate on its contents based on the abstract and any recollections of people who were present. One cannot think about this scenario and fail to reflect on the fragile nature of the personal memories stored in our own brains….

Note added by Mike Perry: Someone I know who is a prominent cryonicist thinks he has notes or text for the speech that was given by Jerry White at the 1969 Cryonics Conference. I have been waiting for the scanned document and will report when something comes to light.

Originally published as a column in Cryonics magazine, February, 2014

Postscript: Jerome White’s paper was (re)discovered by Art Quaife in September, 2014 and published in Cryonics Magazine, October, 2014. The paper is now available online here.

The Case for Brain Cryopreservation

Cryopreservation of just the head is as old as Alcor itself. In fact, some people identify Alcor with its “neuro-preservation” option. It is important, however, to recognize that the objective of preserving the head is really to preserve what is inside the head, i.e. the brain. While I am aware of (contrived) technical arguments that prefer head preservation over brain preservation for information-theoretical reasons, I suspect that no advocate of neuro-preservation is anxious about the prospect of having only his/her brain preserved in a pristine state.

This raises an important question – one that is not immediately evident to the general public. Why not just preserve the naked brain instead? I am aware of at least three major arguments against it and I think that these arguments are based on incomplete information or a lack of imagination.

Myth 1: The isolated brain is not a stable organ and will collapse upon itself in a jellylike state if it is removed from the skull.

Answer: In human cryopreservation the brain would only be extracted at low temperatures which provide a lot more stability to the brain. In addition, in a good case the brain will also be loaded with a cryoprotectant and exist in a dehydrated state, which will provide even more stability.

Myth 2: Removing the brain from the skull will damage the brain and will erase identity-critical information.

Answer: It is correct that morticians typically remove the brain with little regard for its ultrastructural integrity but there is no reason why a cryonics organization should engage in such traumatic brain removal. Safe brain removal protocols are technically possible and cryonics organizations have a strong incentive to develop and refine such techniques.

Myth 3: The skull is necessary to provide protection to the brain.

Answer: It is undeniable that the skull provides robust protection to the brain but from that it does not follow that a cryonics organization cannot design a long-term enclosure and maintenance method that provides strong protection of the naked brain, too.

I do not claim that brain preservation is equal in all respects to neuro-preservation. For example, extraction of the brain from the skull requires additional time after completion of cryoprotectant perfusion and during this time the brain will be exposed to high levels of cryoprotectant (strictly speaking, isolated brain perfusion is possible but this requires a very advanced surgical procedure). Keeping the brain temperature low and uniform during brain removal is also a challenge.

On the other hand, there are potential advantages as well. An isolated brain can be placed in the cryoprotectant to allow diffusion of the vitrification agent prior to cryogenic cooldown to compensate for any ischemia-induced cortical perfusion impairment. In fact, if perfusion is no longer an option, immersion of the (fixed) brain in cryoprotectant is the only means to mitigate ice formation during cryostasis. Another advantage is a decrease in long-term care costs (at least 50%), which allows for lower cryopreservation minimums.

But the most important advantage of brain preservation is that public perception and negative PR would be substantially lower than that with neuro-preservation. Even if the procedure were a little riskier (technically speaking) one could still argue that it is safer in general because images of cryopreserved brains do not risk the kind of visceral response that neuro-preservation triggers.

I cannot do justice to all the technical, logistical, and financial issues associated with brain-only cryopreservation here but the topic requires more study for the reason alone that cryonics organizations occasionally receive fixed brains, or patients with long ischemic times, for whom immersion cryoprotection could be superior to straight freezing. Brain cryopreservation does not exist as an option yet, but it has been the reality for a number of patients.

Originally published as a column in Cryonics magazine, January, 2014

Who Decides What We Can Do With Our Body (and Brain)?

Statement on the High Court ruling concerning 14 year-old cancer victim’s right to cryonics

Click here for PDF

Our hearts go out to the young British woman whose battle with cancer ended sadly earlier this month at age 14, as well as to her parents as they cope with this very difficult time. And we commend the British High Court Judge for his important ruling enabling the girl to obtain her wish to be cryogenically preserved. While we have no comment on the specifics of this case, and do not ourselves offer services of this nature, we hope we can shed some light on the project of experimental medical biostasis / cryonics more generally.

Over the past decade, scientists have made significant advances in low-temperature biology, and scientists developing molecular machines will receive this year’s Nobel Prize on December 10. Many, including scientists at places like Cambridge, Oxford, MIT, NASA and Harvard, now openly support cryonics as a legitimate scientific endeavor. Of course there is no guarantee that any cryonics patients will be revived in the future, but as discussed by four tenured professors in this recent MIT Technology Review piece, the best evidence suggests that cryonics deserves open-minded consideration.

Coordinator of the UK Cryonics and Cryopreservation Research Network, Dr João Pedro de Magalhães, when asked for his thoughts, observed that “no matter the probability you assign to the procedure, we think it’s important to give people the choice, just as we give dying patients the opportunity to try other experimental medical therapies to save their lives”.

Cryonics is a similar experimental treatment, albeit one with different legal and ethical implications, and whose probability of success is unknown. Many parts of the world are now taking progressive stances towards the idea of death with dignity. It seems incongruous with these beliefs to stigmatize a procedure for what is at worst an over-optimistic belief about the state of the future.

Despite the many intermediate successes in low-temperature biology over the past few decades, no cryonics organization can currently revive a patient. Nobody has claimed otherwise, and arguments based on this premise are missing the point.

Cryonicists look at how medicine has progressed over the past hundred years, at the millions of people whose lives would have been cut short if not for advances in technology, and it fills them with hope about what might be possible for the future. The goal of cryonics is not to be able to revive someone with contemporary technology, rather the goal is to preserve a person and her brain well enough that future technologies may be able to (repair and) revive the person. One can think of this as transporting the body forward through time or as medical time travel. This depends on technologies that will be developed in the next decades or centuries, not on the world’s capabilities today. All the major cryonics organizations in the western world are non-profits with the goal of surviving for centuries.

As Aschwin de Wolf, President of The Institute for Evidence-Based Cryonics, explained, “Cryonics is based on the premise that the neuro-anatomical basis of identity is more robust than folk wisdom suggests, and we envision future technologies that can infer the healthy state of the brain from the injured state – and even repair any damage that occurs during the cryopreservation process itself. As such, cryonics is not an act of faith, but an act of reason.”

We will cure cancer one day, and it is reasonable for this girl, born too early through no fault of her own, to choose for herself the best chance to make it to that world where more is possible.

Contact / interviews:

Dr João Pedro de Magalhães

Coordinator, UK Cryonics and Cryopreservation Research Network

+44 151 7954517 /

Aschwin de Wolf

President, Institute for Evidence-Based Cryonics

Appendix of key supporting materials

  • “The patient should participate responsibly in the care, including giving informed consent or refusal to care as the case might be…The patient’s right is based on the philosophical concept of respect for autonomy, the common-law right of self-determinationAmerican College of Physicians Ethics Manual, 2016

Advances in Cryoprotectant Toxicity Research

There is little disagreement among cryobiologists that the biggest limiting factor to reversible organ cryopreservation is cryoprotectant toxicity. It is actually not that hard to create vitrification solutions that completely inhibit ice formation at even the slowest cooling rates. The problem is that such highly concentrated vitrification solutions are too toxic to permit recovery of complex tissues. The least toxic vitrification solution for complex mammalian organs as of writing is M22. M22 is the culmination of many years of experimental and theoretical work by cryobiologist Greg Fahy and colleagues using rabbit kidney slices. Studying selected cryoprotectant mixtures on rabbit kidney slices, Fahy and colleagues came to the following conclusions:

1. High concentrations of a cryoprotective agent (or a mixture of different cryoprotective agents) can prevent ice formation during cooldown and warming.

2. The toxicity of some cryoprotectants can be neutralized by combining them with other cryoprotective agents.

3. The non-specific toxicity of a  cryoprotectant solution can be predicted by calculating a quantity (“qv*”) which is intended to measure the average hydrogen-bonding strength of the cryoprotectant polar groups with the water molecules in the solution.

4. Within limits, non-penetrating agents can reduce the exposure of cells to toxic amounts of cryoprotectants without reducing vitrification ability.

5. Synthetic “ice blockers” can be included in a vitrification mixture to reduce the concentration of toxic cryoprotective agents necessary to achieve vitrification.

While M22 is a low toxicity solution, its toxicity profile still necessitates minimizing exposure time and introduction and removal at low (subzero) temperatures. If we had a better understanding of the mechanisms of cryoprotectant toxicity, vitrification solutions with no toxicity at all could be introduced at higher temperatures and exposure times could be increased to optimize complete equilibration of the tissue with the cryoprotectant. It would also allow safer storage at intermediate temperature temperatures (around -130 degrees Celsius) because ultra-stable vitrification solutions could be used that are less prone to de-vitrification upon re-warming. This would be of particular interest for the cryopreservation of large organs or even whole organisms (with applications such as suspended animation and cryonics).

Two major reviews of cryoprotectant toxicity were published in the last 5 years; Gregory Fahy’s “Cryoprotectant Toxicity Neutralization” (Cryobiology, 2010) and Benjamin Best’s “Cryoprotective Toxicity: Facts, Issues, and Questions” (Rejuvenation Research, 2015).

Greg Fahy’s paper is a rigorous exposition of experimental results concerning the phenomenon of cryoprotectant toxicity neutralization. The paper is mostly limited to the discovery that DMSO can block the toxic effects of amides such as formamide. The combination of DMSO and formamide (or other amides such as urea and acetamide) is indeed one of the building blocks of M22 but this combination cannot be used without limit and the paper includes data that indicate the maximum molar concentrations (and ratios) that still permit full viability. In theory, if two (or more) cryoprotectants would completely neutralize each other’s toxicity they could be the sole components of a vitrification solution. But as the formulation of M22 shows, it is still necessary to add weak glass formers such as ethylene glycol, extracellular CPA’s, and “ice blockers” to supplement the toxicity neutralization obtained with formamide and DMSO. An important finding in Fahy’s paper is that n-methylation abolishes toxicity neutralization for amides and combining methylated amides also does not lead to toxicity neutralization between them. In fact, Fahy found that the presence of n-methylated compounds renders even small amounts of DMSO toxic. The remainder of the paper discusses the mechanisms of cryoprotectant toxicity and Fahy now favors protein denaturation as a plausible mechanism of (non-specific) toxicity. While other cases of toxicity neutralization have been reported in the literature, no rigorous studies have been done to produce a body of knowledge that is comparible to what we know about amide-DMSO interactions.

Benjamin Best’s paper is more general in scope but presents a lot of experimental data and also critically discusses Fahy’s work on cryoprotectant toxicity. As Ben Best points out, different (and seemingly contradictory) results do not necessarily mean that cryoprotectant toxicity is a species or cell-type dependent phenomenon. One could imagine a meta-analysis of cryobiology data in which variables such as concentration, loading- and unloading protocols, exposure temperature, exposure time, and the type of viability assay are matched to ensure methodological consistency. It is also important to compare cryoprotectants at their minimum concentration to vitrify to make meaningful toxicity comparisons. If the work at 21st Century Medicine is an indication, universal low-toxicity cryoprotective solutions should be feasible. Perhaps the most interesting part of the paper is where Best offers a critique of Grag Fahy’s “qv* hypothesis of cryoprotectant toxicity”, which aims to show that non-specfic toxicity concerns the degree to which cryoprotectants leave water available to hydrate macromolecules. This discovery allowed for the substitution of ethylene glycol for propylene glycol in Fahy’s lower toxicity vitrification solutions, despite the resulting higher CPA concentrations. Best observes, “it seems contradictory that water remains available for hydration, but not available for ice formation.” A potential rejoinder to this observation is that so called “bound water” does not participate in ice formation but can be disturbed by strong glass formers. Best also suggests a potential refinement of qv* that allows for more precise calculation of the hydrogen bonding strength of the polar groups that are used to calculate qv*. It is conceivable that such a refinement would eliminate the few remaining outliers in the data that support the qv* hypothesis. The paper also draws attention to the possibility of kosmotropic co-solvents and changes of pH and microenvironment polarity to mitigate cryoprotectant toxicity.

Neither of the papers discusses cryopreservation of the mammalian brain, but there is good reason to believe that in the case of this organ modification of low-toxicity vitrification solutions is required. Conventional cryoprotective agents such as PG, EG, and DMSO have poor blood brain barrier (BBB) penetration and the brain may not tolerate the CPA exposure times that other organs do. For example, while M22 can be used for cryopreservation of the brain, many of its component have poor BBB penetration and PVP and the ice blockers (X-1000 and Z-1000) are assumed not to cross the (non-ischemic) BBB at all. One potential solution is to (reversibly) open the BBB with so- called BBB modifying agents like detergents or perhaps to search for cryoprotective agents that can cross the BBB.

The most fundamental question in the design of vitrification solutions remains whether it is possible at all to introduce high concentrations of cryoprotectants without creating any kind of irreversible molecular and ultrastructural adverse effects. Understanding what specific and non-specific cryoprotectant toxicity exactly is should enable us to answer this question.

Originally published as a column (Quod incepimus conficiemus) in Cryonics magazine, September-October, 2016

Groundbreaking Scientific Results Prove that the Proposition of Human Medical Biostasis has Potential and Needs to be Brought into Mainstream Scientific and Medical Focus

Breaking News [Media Press Package with additional detail]

A team from 21st Century Medicine has developed a technology that has been independently verified to enable near-perfect, long-term structural preservation of a whole intact mammalian brain.

This new breakthrough just won the Brain Preservation Prize – five years after it was launched by the Brain Preservation Foundation (BPF).

“One of the, if not THE, most important scientific results in the history of medical biostasis and cryonics has been accomplished” Aschwin de Wolf, President of The Institute for Evidence-Based Cryonics

According to the BPF, 21st Century Medicine narrowly beat a team led by Dr. Shawn Mikula at the Max Planck Institute of Neurobiology (published last year in Nature Methods).

In addition to proof of this accomplishment and the full 21st Century Medicine “Aldehyde-Stabilized Cryopreservation” protocol recently being published in the journal Cryobiology, it was also independently verified by the BPF through extensive electron microscopic examination.






The prize was independently judged by neuroscientists Dr. Sebastian Seung, Professor at Princeton University and Dr. Kenneth Hayworth, President of the BPF.

“Imagine being able save, and at low temperatures, indefinitely preserve people who can no longer be sustained by contemporary medicine so that future medicine can both revive them and restore their health – these results provide strong support of that being possible”

Dr. JP de Magalhães, Chair of the UK Cryonics and Cryopreservation Research Network

This follows recent scientific evidence that long-term memory is not modified by the process of whole organism cryopreservation and revival in simple animal models.

As the two leading think-tanks/scientific networks in cryonics we share here a brief with both more color and our perspectives on what this important breakthrough means and – does not mean – for cryonics. 

In the words of Dr. Ken Hayworth, President of the Brain Preservation Foundation, and one of the prize judges:

“Every neuron and synapse looks beautifully preserved across the entire brain. Simply amazing given that I held in my hand this very same brain when it was a vitrified glassy solid… This is not your father’s cryonics”

Recent developments relevant to cryonics

A lot of interesting pieces related to cryonics have appeared over the last few months that I thought I would share:

Four professors conclude in MIT Technology Review that there is significant and growing body of evidence in support of human cryopreservation: “The Science Surrounding Cryonics” 

New York Times Cover story by Pulitzer Prize winning journalist on “A Dying 23 Year Young Woman’s Hope in Cryonics and a Future”

Skeptic Michael Sherman writes a piece in Scientific American called  “Can Our Minds Live Forever?”

Here are three recent important peer reviewed papers:

Dr. Greg Fahy and Robert McIntyre of 21st Century Medicine describe here a new cryobiological and neurobiological technique, aldehyde-stabilized cryopreservation (ASC), which demonstrates the relevance and utility of advanced cryopreservation science for the neurobiological research community. The ASC technology is now also competing against Dr Mikula at Max Planck in he brain preservation prize.

The Grand Challenges of Organ Banking and It’s Potential is described by large group of the worlds leading cryobiology scientists:  The first Organ Banking Summit was convened from Feb. 27 – March 1, 2015 in Palo Alto, CA, with events at Stanford University, NASA Research Park, and Lawrence Berkeley National Labs. Experts at the summit outlined the potential public health impact of organ banking, discussed the major remaining scientific challenges that need to be overcome in order to bank organs, and identified key opportunities to accelerate progress toward this goal. Many areas of public health could be revolutionized by the banking of organs and other complex tissues, including transplantation, oncofertility, tissue engineering, trauma medicine and emergency preparedness, basic biomedical research and drug discovery – and even space travel.

Persistence of Long-Term Memory in Vitrified and Revived Caenorhabditis elegans. Two scientists ask the question:  “Can memory be retained after cryopreservation?” and then demonstrate that a form of long-term memory in C. elegans is not been modified by the process of vitrification or slow freezing.

Beyond Skull and Skin: Concepts of Identity and the Growth of Cryonics


“Where does the mind stop and the rest of the world begin?” So begins a 1998 paper by Andy Clark and David J. Chalmers called “The Extended Mind.” In this much discussed article they defend the position that cognition, or the mind, does extend beyond the skull and can include objects or operations performed outside of the body, such as the use of calculators or notebooks. There are a lot of complicated and intricate issues involved here but I want to draw attention to the following passage at the end of their paper:

What, finally, of the self? Does the extended mind imply an extended self? It seems so. Most of us already accept that the self outstrips the boundaries of consciousness; my dispositional beliefs, for example, constitute in some deep sense part of who I am. If so, then these boundaries may also fall beyond the skin. The information in Otto’s notebook, for example, [Otto has Alzheimer’s disease] is a central part of his identity as a cognitive agent. What this comes to is that Otto himself is best regarded as an extended system, a coupling of biological organism and external resources. To consistently resist this conclusion, we would have to shrink the self into a mere bundle occurrent states, severely threatening its deep psychological continuity. Far better to take the broader view, and see agents themselves as spread into this world.

If we consider the idea that the self extends beyond the skull and skin, how does this affect our understanding of identity? Clearly, the self and identity are closely related and I suspect that many people would agree that a rich understanding of identity is not exhausted by considering a person’s brain and body. In this article it is not my intention to wade too deeply into semantic issues, or attempt to resolve philosophical debates, but to argue the point that the public perception of cryonics would benefit from embracing a richer concept of identity that includes a person’s social environment, life achievements, possessions, and other assets.

Reductionism in Cryonics

One might argue that cryonics is itself a form of reductionism because it approaches the brain solely as a biochemical entity. This can be admitted, but in this sense it is no more reductionist than the premise of mainstream medicine and neuroscience. In fact, in a properly conceptualized vision of cryonics one can remain agnostic about debates concerning “materialism” or “the soul.” What matters in cryonics (and in medicine in general) is whether approaching the brain from a biological perspective can produce meaningful treatments for medical conditions. I think it is rather obvious that the answer to this question is “yes.”

There is another sort of reductionism associated with cryonics that is more controversial, or perhaps I should say, less appealing to many people. The idea is that preservation of the body is identical to the preservation of a person’s identity. If we can cryopreserve the person’s body in a manner that permits future resuscitation of the person, then his identity has been preserved. In cryonics this idea has often been the starting point for further reductionism. The most notable example is the idea of neuropreservation in which only the brain (usually protected by the head) is deemed to be necessary for the preservation of identity. Neuropreservation raises a lot of complex issues which I will not address here and have covered in another publication.

The most important point I want to make here is that our concept of the self or personal identity is not exhausted by our brains and that our existing bodies mean something to us, even if faced with the argument that an “identical” or “improved” body can be made for our cryopreserved brain in the future.

This kind of reductionism does not stop here. I have even seen arguments that what “really matters” is preserving the hippocampus, presumably being the seat of our memories. For most people, however, our life history (which is closely associated with our identity) cannot be reduced to memories and cognitive operations. The brain is about a lot of other things, too.

Reductionism can also express itself through a position that only “structural” preservation matters, usually confined to the “structural” preservation of the brain. If this argument is made in defense of the cryopreservation of non-ideal cases, under the assumption that as long as the original structure can be inferred from the damaged structure, it is a commendable position. However, how much brain structure must be preserved to prevent information-theoretic death is not something that can be known with certainty and the most conservative approach is to aim for making our procedures reversible by contemporary medical criteria. We do not yet have a good enough understanding of the neuroanatomical basis of personhood to make such a sharp departure from mainstream medical validation.

Cryonicists who believe in “substrate independent minds” (i.e. mind uploading) would even argue that repair and restoration of the original structure is not necessary and perhaps even inefficient. We can “just” do a molecular scan of the (damaged) structure of the cryopreserved brain, reconstruct the original structure “in silico,” and revive the person in a computer. In this vision, identity is not just reduced to brain but to information about the brain.

We now have identified various concepts of identity. At one extreme we have a very rich concept that not only includes a person’s brain and body but also his social environment, assets, and life achievements. At the other end of the spectrum is the idea that a person’s identity can be captured by a scan of their brain ( and perhaps even just the hippocampus). In the remainder of this article I will defend the position that if we want cryonics to appeal to a wider audience we should embrace a much richer concept of identity.

The Failure of the Cryonics Movement

Since the 1980s cryonics organizations have not failed in keeping their patients in cryopreservation. In that sense, cryonics has made impressive progress compared to the days when patients where often moved from one location to another because of insecure funding, sometimes culminating in having to let them thaw. Where the cryonics movement has not been particularly successful is in persuading the general public, or at least a substantial number of people, to make cryonics arrangements. This lack of enthusiasm for cryonics has been discussed intensely in the cryonics community and several reasons have been put forward: scientific credibility, affordability, transparency of cryonics organizations, ignorance, irrationality, religion, a pro-mortalist culture, or fears of the future. In my personal experience, the two major reasons for not choosing cryonics are a lack of confidence in its scientific feasibility, and a fear of future alienation.

Let me be clear that I think it is extremely important to demonstrate the scientific feasibility of cryonics. Even if it doesn’t make cryonics a whole lot more popular, improving our procedures and developing credible resuscitation technologies, is of great importance to the people who have chosen cryonics. I do not think, however, that demonstrating the scientific feasibility of cryonics (i.e. human suspended animation) will produce a substantial attitude change towards cryonics.

First of all, I think it can be quite persuasively argued that the scientific case for cryonics is already quite strong. Ideally, we can cool down the patient to 0°C without compromising viability. The newer generation of vitrification agents can eliminate ice formation in the brain and preserve its fine ultrastructure. The ongoing trends towards miniaturization in manufacturing (such as 3D printing) and biology eventually will give rise to molecular repair technologies that can reverse aging and repair any damage associated with today’s cryonics procedures. One would believe that these developments are at least plausible to hundreds of thousands of people, if not millions. Instead, the number of people who have made cryonics arrangements does not exceed 2,000 (as of writing).

There is another way of looking at this. If insufficient scientific credibility is the reason for the lack of enthusiasm for cryonics how can we explain that millions of people spend hundreds of thousands of dollars on unproven cures when diagnosed with a terminal condition? How can we
explain the much greater popularity of astrology and all kinds of “esoteric” healing? A stunning number of people in the United States believe in the existence of ghosts (according to one poll, 45%!). Are we really supposed to think that the scientific arguments favoring the claims of astrology or the existence of ghosts are stronger than those favoring cryonics? The argument that scientific credibility is holding back cryonics cannot withstand close scrutiny and fails to take into account what moves most people to endorse an idea.

For example, the famous science fiction writer and science popularizer, Arthur C. Clarke, was no stranger to cryonics. He even assisted Alcor during its legal battles in the 1980s. As he states in a supportive letter, “Although no one can quantify the probability of cryonics working, I estimate it is at least 90%—and certainly nobody can say it is zero.” For a long time, Alcor’s Cryonics magazine had one subscriber in Sri Lanka, presumably Clarke who lived there. But even Clark had no personal interest in making arrangements. (He died in 2008, and was buried.) Clark is no exceptional case. There are a lot of people who believe cryonics is plausible. What concerns them is not that cryonics may not work but that it will work, thrusting them into a distant, unknown future with obsolete skills and no money, friends or family.

Most people do not associate cryonics with continuing their lives but with losing everything they care for as the price of admittance to some dystopian neverland—not a very appealing prospect. I do not know if we can completely neutralize those fears, or even make cryonics at all appealing to the great majority. But I do think some progress can be made if we embrace a richer concept of identity and let it shape our communication about cryonics and the services we offer.

Preserving the Extended Self

I will refer to this richer concept of identity as the “extended self.” It does not just refer to the brain or body of the patient but also to his friends and family, his career and achievements in life, his assets and possessions. The concept of an “extended self ” is not just a theoretical construct but has already been used to great benefit in the study of marketing and consumer behavior. If the aim of a cryonics organization is to preserve the extended self, what changes would need to be made? In the most general sense, it would require that we listen carefully to people about what makes them uncomfortable about being cryopreserved. We do not need to start from scratch here. We know what the predominant concerns are. I think that the common denominator that runs through most concerns is that people want their post-revival life to be a continuation of their existing life. There is one notable exception and that is people would want to be cured of the medical condition that caused them to be cryopreserved. In most cases this will require not just curing this disease but also reversing aging. It is important, however, to make it clear that these post-resuscitation decisions can and should be made by the person in question. This is why it is important to present a wide variety of visions of the future that will appeal to a wide range of people.

One unappreciated point about cryonics is that the delay between pronouncement of legal death and resuscitation only exists for people other than the patient. From the subjective experience of the patient resuscitation will be instantaneous. So I suspect that many of us would like a home to return to and continue our life. Unless we live in a post-scarcity economy where money has lost its utility it would also be helpful if we can continue to afford living in our homes and make purchases. Then there are also our personal belongings. If we are able to return to our homes a lot of those should be available once again as well. In short, “taking it with you” is not just a matter of setting up a personal trust but should extend to a person’s money, property, and possessions.

Of course, we cannot expect society to remain static when we are in cryopreservation and the organizations or companies entrusted with these responsibilities will need to be authorized to adapt to these changes. Does a house need to be renovated? What kind of upgrades need to be installed to keep up with technological changes in residences? Should one’s money (or a portion thereof) be exchanged to new digital currencies? Which personal belongings need to be replaced with newer items and which should be retained in their original state for personal or sentimental reasons? We cannot consult the patient in cryostasis and will need to be guided by common sense, written and verbal instructions, and practical considerations. I suspect, however, that most people would agree that an effort to maintain and upgrade our assets and possessions is much preferred to not having any at all.

When it comes to our social connections things are both easier and more difficult. Unlike managing a residence or personal belongings we would not have to make decisions about what to keep and not to keep. We would like to be reunited with our loved ones, family, and friends. Would it not be a lot easier to adapt to a new world if the people who were closest to you before you got seriously ill will be there, too? The biggest challenge here is to present a vision of cryonics where such a scenario is the logical and moral choice. Where making cryonics arrangements is the expression of social connectedness and family values, instead of being perceived as going it alone. This will not be a trivial task but I do not think we can claim, today, that we have put a lot of effort into this. I also suspect that cryonics organizations that make an effort to keep people who have been cryopreserved visible and part of our memories will have an easier time to convey the social nature of cryonics.


Will my skills, qualifications, degrees, and career achievements be completely irrelevant in the future? That is a frequently expressed and justified concern about cryonics. I have decided to treat this topic in this section about reintegration because I think it would not be plausible to claim that a cryonics organization (or associated organization) can successfully claim to resolve this completely.

The first point I want to make is that for many people who are revived in the future returning to their prior job may not be the most urgent matter provided their assets have been well preserved. In fact, even assuming a moderate growth rate, a patient in cryopreservation has a reasonable chance to come out rather well because no withdrawals are made for daily living expenses (aside from a modest asset management fee). Considering the fact that most people are cryopreserved at an old age, many of us will have accumulated some assets that can be preserved and invested during cryostasis.

Not everyone will be completely satisfied with this answer, or optimistic about their financial status in the future, but I think it is not realistic either to ignore this point. As far as the question
of obsolete skills is concerned, I suspect we will see a lot of variability here. People with skill sets that are known to change in the future (for example, maintenance of landline telephones) may be faced with greater challenges than people who work in “timeless” occupations such as artists
who use traditional means of expression (painting) or wine makers. It will be fair to say, however, that the vast majority of people who have been cryopreserved for a long time (more than 100 years) will need to adapt to changes in occupations.

If a person comes out of cryostasis moderately secure, I do not think this constitutes a formidable challenge. The prediction that technologies will accelerate in the future does not necessarily mean that it will become harder to adapt. Even for people who are not cryopreserved during this period a greater pace of technological change will produce a corresponding demand for means to adapt to these changes. I suspect that a lot of these changes can be broken down into several distinct components and some of them can be addressed when the person is in cryostasis. For example, if society changes from email to a different kind of online communication we would expect that a cryonics organization (or whoever administers and maintains the patient’s communications) would make sure that the patient will be able to access his correspondence in a contemporary format. One can think of things that can be done during a person’s absence that will allow her to adapt more quickly and successfully. Reintegration does not start after resuscitation but should be an ongoing concern when the patient is cryopreserved.

The aim of a credible cryonics organization should not only be to cryopreserve the patient but to assist in re-integration into society, too. It stands to reason that when a cryonics organization is reasonably confident that resuscitation is imminent, increasing thoughts will be given to the reintegration of their patients. Not all cryonics organizations may have such a strong emphasis (or set aside money for this), though, but confidence in an organization’s motivation and ability to do so could become an important criterion in choosing cryonics organizations. It is also likely that future charitable and for-profit organizations will focus their attention on reintegration of cryonics patients.

In closing, there is another aspect of reintegration that needs to be pointed out. People often tend to think of a revived cryonics patient as an “intruder” in a new society. Is that a reasonable assumption? Why not consider the idea that such people will be approached with a mix of curiosity and admiration? Why assume that revived cryonics patients only have things to learn and nothing to offer? Occasionally, advocates of cryonics are accused of being too “utopian” but it cannot be denied that a lot of skeptics have distinct dystopian views of the future. Which brings me to my last point. Cryonics organizations and their members should make an effort to present realistic but desirable visions of the future. The emphasis here is on visions. Instead of imagining the future as something scary, or at least as something presenting a series of challenges, it would be nice to be offered a panoply of good reasons to want to live longer.


Cryonics, no doubt, will always be associated with cryopreservation of the body or brain. That is the core activity of a cryonics organization. But if we want more people to make cryonics arrangements, we need to embrace a much richer concept of identity that gives people the impression that our ultimate goal is to ensure that their lives will be continued after resuscitation
instead of being dumped in a foreign and incomprehensible world. I am not arguing that cryonics organizations should feel exclusively responsible for this but I do think we can do a lot better than we are doing today and hope that more people will be motivated to further strengthening their cryonics organizations along those lines.

Cryonics as a measure of rationality?

Most cryonics advocates are often frustrated by the amount irrationality, ignorance, and hostility when other people encounter the idea of human cryopreservation. It should not be surprising then that some of us have simply concluded that most people “just don’t get it.” Which raises an important question. Is making cryonics arrangements a strong measure of rationality? After all, a close examination of Alcor members indicates that most of them are highly educated, a disproportionate number of them have PhDs, and their backgrounds are often in fields where strong analytic skills are required; computer science, neuroscience, biochemistry, etc. Another indicator is that cryonics is relatively popular in communities with a high proportion of “nerds.” In fact, a number of “leaders” in the “rationality” community (Robin Hanson, Eliezer Yudkowsky) have cryonics arrangements and have made public arguments in favor of cryonics. In short, someone who has made cryonics arrangements is not prone to short term gratification and minimizes cognitive biases, one could argue.

The problem with this characterization of cryonics as a measure of rationality is that it does not explain why the overwhelming number of people who can be considered highly analytical or rational have not made cryonics arrangements. Many cryonicists are smart but most smart people are not cryonicists. To explain this we will have to look elsewhere.

The 18th century skeptic and analytical philosopher David Hume once wrote that “reason is a slave to the passions.” In the case of cryonics, no matter how smart a person is, if the person does not have a passion for life (and an aversion to death and aging) that person will not be primed for an enthusiastic personal endorsement of cryonics. Closely related to having a desire to live and to pursue life extension is a an optimistic temperament. A cryonicist is not necessarily “wildly” optimistic, but (s)he should at least think that life is worth living and not be prone to thinking about the future in dystopian terms. I am also inclined to think that such a person is prone to think “like an economist” (to use Bryan Caplan’s phrase). With this I mean that a person can think in a probabilistic manner, does not see the world as a “zero-sum game,” and sees developments like automation, computerisation and biotechnologies in a positive light.

Do these combined traits produce a favorable attitude towards cryonics? This still cannot be the complete story because the traits discussed so far are shared by many millions of people in the world and support for cryonics is extremely small. I want to single out two additional traits that are usually required to prime someone for cryonics. The person also needs to be a non-conformist of some kind. When cryonics is as small as it is, strongly endorsing cryonics makes someone stand out (to put it mildly). And this “standing out” is not comparable to just having a bizarre hobby or a strange sense of style. It can sometimes produce confusion or hostility in other people, which can turn even our most life-affirming friends and family into apologetic pro-mortalists.

The most important trait, in my opinion, and the one that really distinguishes the cryonicist from the non-cryonicist, is the ability to deal with vulnerability, uncertainty and the unknown — in some cases, to even welcome it. People who have been around in cryonics for awhile know that ultimately (that is, when you dig a little deeper) skeptics are really afraid to be resuscitated in a distant and unknown future. This should not be easily dismissed. Personal identity is not identical to the brain or the body (as a simplistic version of cryonics would have it) but extends to all the things and people that have become part of a person’s life. To many people, the cryonics proposal means  survival at the cost of losing everything that gives meaning to their lives.

If we look at the limited acceptance of cryonics from this perspective, does this inspire optimism in persuading more people? An immediate response would be negative because fundamental character traits are hard to change. Another approach, however, is to change the conceptualization and delivery of cryonics so that these fears are not triggered. In particular, it might serve a cryonics organization well to transition from an organization that just “stores” a human body or brain without specific resuscitation and reintegration scenarios to an organization that offers more comprehensive means of identity preservation. Such an organization puts a strong emphasis on the cryopreservation of families and friends. It will offer means of asset preservation and personal belongings. It develops specific resuscitation protocols which are updated and calibrated as our knowledge and technologies improve. And it makes serious efforts to provide a reintegration program which seeks to minimize adjustment to the time in which an individual is resuscitated.

Is endorsement of cryonics a measure of rationality? Yes, but without a desire to live, a reasonably optimistic attitude, an independent mindset, and, most of all, confidence in a cryonics organization to preserve all that is important to a person, being smart by itself is not going to do it.

This is a web-exclusive edition of the Cryonics magazine column that was omitted from the April 2015 issue.