Brain preservation is the process of carefully preserving and protecting the information in someone’s brain for an indefinite length of time, with the goal of reviving them if technologic and civilizational capacity ever progresses to the point where it is feasible and humane to do so.
1. Important aspects of your memory and personality are stored via static information structures in your brain. If you could preserve your brain prior to your information-theoretic death, you could theoretically pause your life and wait until society’s technology has matured to the point that society is able to revive you, if this ever becomes possible.
2. With current methods, we can potentially preserve the information in your brain for the long term. There are multiple possible methods to attempt to accomplish this, each with upsides and downsides.
The idea of preserving people with the goal of future revival is a very old one. In the early 1960s, it received its first serious modern attention, with the 1962 private publication of two books that both focused on preservation via cold temperatures. Robert Ettinger spoke of the idea “to preserve dead people” while Evan Cooper spoke of “bodily preservation” (Ettinger, 1964) (Duhring, 1962).
It was not until 1965 that Karl Werner came up with the neologism “cryonics,” a portmanteau of “cryo-,” meaning cold, and “-onics,” from “bionics,” to describe the procedure (Krüger, 2010). “Bionics” itself is a portmanteau of biology and electronics that is related to the field of cybernetics. Although cybernetics lost credibility as a field in the 1980s, it was highly influential in the early cryonics world, as it helped to conceptualize biology as an information science (Fisher, 2021).
Cryonics, sometimes mistakenly referred to as cryogenics (the study of materials at cold temperatures in general), has been the term most commonly used to describe the idea of preserving people via cold temperature with the hope of future revival ever since Werner coined it.
It’s unclear when the term biostasis first began to be used, but it was certainly used by the 1980s. For example, biostasis was the term used in Eric Drexler’s 1986 book Engines of Creation to describe the procedure of preserving people with the goal of future revival (Drexler, 1986). As a term, biostasis is more biophysically descriptive than cryonics. It is also more procedure-agnostic, not necessarily implying the use of cold temperatures. Biostasis is also sometimes used in microbiology to refer to growth inhibition of microorganisms, for example as a result of dehydration (Paerl et al., 2003).
In 2010, John Smart was looking for people interested in chemopreservation, which is the idea of long-term preservation without cold temperatures. He did a domain search for chemopreservation.org and discovered that Ken Hayworth already had this domain name. John got in touch with Ken through the website registration info. They decided that brainpreservation.org was more inclusive and they co-founded the Brain Preservation Foundation (John Smart, personal communication).
Brain preservation – the term – represents a substantial shift in the implied goals of the procedure. Specifically, it shifts the focus very much to the brain, which in my view had hitherto been a deficiency of the body preservation/cryonics/biostasis movement. One of Ken and John’s aspirations was to incentive the development of a procedure that could provably preserve a particular aspect of the microanatomy of the brain, known as the connectome.
The description of a core aspect of cryonics as brain preservation was not completely novel. For example, in the year 2000 Kennita Watson discussed brain preservation on the Cryonet mailing list.
One concern about the term brain preservation is that there is not necessarily an implication of being able to store the brains for the long run. The term is used frequently in the scientific literature to describe short-term (hours to days to weeks) preservation of the brain with the goal of carrying out a particular experiment and then discarding the brain afterward.
As an alternative/complementary term to brain preservation, I came up with the term brain conservation. Merriam-Webster defines conservation as “a careful preservation and protection of something.” To me, brain conservation has a useful connotation of stewardship of the preserved brains until the far future, until either whatever the person wants for their brain is within the realm of technical and practical feasibility, or until protection is no longer possible.
One issue with the term brain conservation is that it might be confusing to the average reader to alter the term of such a new field. Eventually, perhaps both terms could be used, with brain conservation describing more of the long-term protection and stewardship aspects, and brain preservation describing the initial preservation aspects (e.g., cryopreservation or fixation).
It’s important to point out that brain conservation is not necessarily only about the brain: parts of – or the whole rest of the body – could be conserved as well. The idea is just that the brain is the most important part and should be the focus of the procedure.
I try hard to be an inclusionist. I encourage and support the endeavors described by all of these terms. I also don’t think the terminology is that big of a deal. In the end, it’s just semantics. I’m just explaining why I personally prefer the terms brain preservation and brain conservation. Sometimes I will use these other terms as well. In these essays, they all refer to the same general thing.
In a brilliant essay on cryonics, Tim Urban made the analogy that choosing to preserve yourself is like being on a plane that you know will soon crash and choosing to use a parachute that has never been tested to jump into an unknown land.
In the evidence based medicine literature, using a parachute when jumping out of a plane is a classic example of a practice that, by the strictest medical standards, is non-evidence based (Smith et al., 2003). This is because there have been no randomized control trials showing that the use of parachutes improves survival.
Similarly, there have been no randomized control trials that test whether or not revival is possible following long-term brain preservation. Until society has advanced far enough to say more definitively whether it can work, we will be stuck in our current state of uncertainty. Even though the structural preservation component can and should be rigorously tested by current scientific methods, the most important outcome of brain preservation – the possibility of revival – will remain non-evidence based.
So is brain preservation a science or pseudoscience? I don’t think that’s a well-formed question. Just as with psychology, brain preservation is a subject area that can be approached scientifically or non-scientifically. In my opinion, calling the subject area either a science or pseudoscience just speaks to one’s own opinions and experiences about the topic, rather than making a claim about reality. Objectively, it has clearly been performed and marketed in highly pseudoscientific ways, so it is understandable that some people call it pseudoscience.
Related to the claim of pseudoscience is the claim of wishful thinking. A lot of people think that this whole idea is simply wishful thinking and therefore not worthy of serious consideration. For example, in a 2019 Twitter discussion with Ken Hayworth, neuroscientist Ken Miller claimed that it was wishful thinking: “Or in my case, not saying ‘meh,’ but firmly believing that the idea that we have a way to cheat death is as illusory now as it has always been. People want to believe they will be the ones who won’t have to die. Illusions spring eternal. Someday far away it might be real.”
It’s certainly true that people have been seeking the fountain of youth and other ways to avoid death for centuries. The fountain of youth is still undiscovered. With the benefit of hindsight, some of the ways that people have purported to accomplish this seem ridiculously optimistic. The history of anti-aging is replete with wishful thinking, as described in Stambler’s A History of Life-Extensionism in the Twentieth Century (Stambler, 2014). Brain preservation is a little bit different because it is in large part a claim about future technology rather than current technology, but it could easily fit into this reference class as just another misguided, wishful thinking-based attempt to defeat death.
This type of argument inevitably instantiates a game of reference class tennis. That’s because this same type of reference class forecasting also has a long history of being wrong about technological developments.
A classic example is flying machines. They were talked about forever. Up until the point in which they were made, critics used this as implicit evidence that they could not be made. In 1896, an expert wrote “I have not the smallest molecule of faith in aerial navigation other than ballooning.” In 1901, an expert wrote “man is to-day no nearer fulfillment than he was ages go when he first dreamed of flying through the air” (Melville, 1901). And then, in 1903, Kitty Hawk.
So in my view, it’s a toss up if you want to use reference class forecasting. It’s certainly not a slam dunk argument against brain preservation. True, many humans have long thought that they wouldn’t have to die and that the fountain of youth was just around the corner. In hindsight, many of these hopes were highly misguided. But humanity has also figured out technologic solutions to all sorts of other problems, biological and otherwise, that have vexed us. What makes this problem so special?
Clearly, experts can be wrong when they shout down iconoclasts in their field. Another classic example is rocketry research. Robert Goddard (1882–1945) was one of its pioneers. He was ridiculed for it in his era. In 1920 the New York Times published an editorial attacking Goddard, claiming that he “seems to lack the knowledge ladled out daily in high schools.” This was famously corrected in 1969.
The list goes on. There are countless other examples where an expert says something won’t ever be possible, and then it does become possible within just a few decades. Notably, the person who said it has often died by then, so they die often believing that they were still right. Human time horizons are quite myopic.
But while experts can be wrong and we must discount the opinion of any one person, they are also often right. All in all, honest expert opinion is a decent proxy for what will and won’t be possible in the future and is certainly worth consideration. As Carl Sagan pointed out, “they laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown.”
With all this said, what do the experts think about brain preservation? Mostly, there haven’t been very many opinions. When people do give opinions, they tend to be superficial and not addressing obvious counterarguments. For example, sometimes an expert cryobiologist will say that it is not possible for brain tissue to be preserved in a viable state, which is quite true – but this is a claim about long-term suspended animation, not brain preservation. Brain preservation is a highly interdisciplinary field, and unless people care about the subject matter, few people become knowledgeable in the relevant sub-domains to make incisive criticisms; however, I will try to refer to and discuss expert opinions where possible.
Funding for brain preservation research is a chicken and egg problem. As has been pointed out many times, there’s effectively no money for it because there is no market; conversely, there’s no market because there has effectively been no research on it.
When a close friend of mine first heard about my interest in this field, he said, “if this was legit, there would be a huge number of people working on it, funded by the government.” On the one hand this makes sense, but on the other hand it is a bit nihilistic. Because how can the transition to credibility ever actually happen? It’s relying too much on the efficient science hypothesis. It’s like saying that you can never find a $100 bill on the ground, because if it was there someone else would have picked it up.
Sometimes this chicken and egg problem can be solved by an influx of significant funding of a field, but that hasn’t happened. My guess is that it almost certainly won’t happen in the near term, as the research is considered controversial and most government science funding agencies and large non-profits are highly risk averse. It’s also important to recognize that science funding in general is very limited and that government funding of brain preservation would take away from other worthy causes.
The lack of research funding is most unfortunate, because clearly this is an important problem. As Jean Rostand, a pioneering researcher in cryobiology, put it in the the preface to The Prospect of Immortality, “what [Robert Ettinger] is telling us is that we must begin; the job will be done some day, and for every day that we put it off untold thousands are going to an unnecessary grave” (Ettinger, 1964).
The other reason that the lack of research in cryonics has been a big problem is that it has alienated scientists. Rostand himself was an example of this, as he reportedly became disillusioned with the way that the field of cryonics evolved in the 1960s and 1970s.
Some research is happening. I will try to discuss it, but progress is slow. It goes in fits and bursts based on the life events of a small number of motivated researchers. There is a need for more researchers involved in the field.
These are my work-in-progress essays and notes on brain preservation. One day, they may eventually be combined and integrated into a book; however, for now they are living documents.
The main reason to publish it online in draft form is that I am seeking comments from other scientists and the public at large. Most importantly, I am seeking criticism about areas in which I am mistaken and ways that the ideas could be improved upon.
I expect that much of what I have written is wrong. I have researched and written this during my free time. Moreover, the field requires such interdisciplinary thinking that I expect achieving expertise in all of the relevant areas would be close to impossible even if it were my actual job. Here are three major sources of error in these essays:
1. I may have incorrectly understood or inferred something from a source.
2. I may have focused on one source that is outdated or biased, even though the current consensus in the field is actually something else.
3. The consensus in the field might be wrong. This would not be surprising. It happens all the time in biology and medicine.
I seek pointers to all of these sources of error within what I have written, and other types of error not described. For now, errors/problems/suggestions are best noted by emailing me: amckenz at gmail.com.
Even more helpful than pointing out where I am wrong is coming up with a better view of the situation yourself and publishing it or posting it online. Most of these essays were written by reading the available literature, thinking about the problem, seeing where I agreed and disagreed, and then writing it up. If more people were to do the same, the field as a whole will converge upon the truth.
1. Perhaps I will learn that the whole project is doomed to failure. Based on my experience so far, I doubt that will happen, but I try to be open-minded to the possibility of this. I am not obsessed with personally not dying. My main reason for researching brain preservation is because I believe it is a promising approach to save lives. If there is a convincing case that brain preservation will in fact not save lives, I would very much like to hear of it. This way I can avoid wasting my time and energy on it and instead focus on other things.
2. Perhaps I will learn that certain preservation methods or approaches are doomed to failure, but that others could conceivably work. Obviously this would be very valuable, because it could redirect efforts into more fruitful areas.
3. Perhaps I will learn that multiple of the preservation methods have a good chance of working. In that case, we can focus on the cheapest and most accessible methods. Perhaps there is a trade-off between cost and likelihood of information conservation. This would be very good to know as well, so that people can make their own decisions based on the trade-off landscape and their values/resources.
It means that I am not trying to convince anyone that they should do anything. Instead, this is an academic/scholarly discussion of the topics relevant in brain preservation. My ideal goal here is as a truth seeker.
Do I have opinions about what people should do with respect to brain preservation? Of course I do. But to the extent possible, I have endeavored to not let this bias what I have written. Obviously, I am not claiming to have a neutral point of view. Like everyone else, I have an authorial bias.
To be more explicit about my biases, I think that brain preservation is a reasonable idea. I actually think it is kind of obvious and I expect that one day most of society will agree with that idea, assuming that technology continues to progress and we don’t kill ourselves first or otherwise suffer a civilizational collapse.
That said, my goal is certainly not to prove that brain preservation is definitely going to work or that it is more likely to work than not. It is a trite but worthwhile point that no one can predict what is going to happen in the future with certainty.
My goal is also certainly not to convince anyone that they themselves should undergo a brain preservation procedure at the time of their legal death. I am not endorsing any cryonics, biostasis, or brain preservation organizations.
Here are three groups of people who might be interested:
1. The first group of people are those who are already interested in brain preservation. For example, this group includes people who are committed cryonicists/brain preservationists.
The philosopher Montaigne once said that to study philosophy is to learn how to die. Perhaps it could also be said that one goal of studying science is to learn how to not die. If that’s what you want for yourself, your loved ones, and/or to help other people with, perhaps you will find these essays helpful.
2. The second group of people are those who themselves know that they do not want brain preservation. Perhaps you even find the idea repulsive and are reading this out of morbid curiosity.
I will not try to convince you to do brain preservation. I support your right to dispose of your body upon legal death in any way that you prefer, whether that is embalming, cremation, natural burial, alkaline hydrolysis, or any of the other options available to you.
As you learn about brain preservation, you may decide to support the rights of your fellow humans to pursue brain preservation if that is what they want to do. In this case, you could consider becoming an ally of those who do want brain preservation. There are many legal and social barriers that get in the way of people pursuing it.
I try to have a sympathetic reading of critics as they are usually operating under a different paradigm. For example, they may not agree with the idea that death is a process. If people better understand what the paradigm is in brain preservation, they may be able to more effectively poke holes in it, of which there are plenty, rather than critiquing a strawperson. This will make their critiques more valuable.
3. The third group is people who are curious about brain preservation. As above, I will certainly not try to convince you to do it, as I am not trying to convince anyone to do anything in these essays. I will instead try to lay out the rationale, my current understanding of the theory/evidence, and the expected risks and benefits. Perhaps this will help you make your own decision based on your goals, values, and experiences.
Survey data suggests that about 20% of people could imagine undergoing brain preservation today if it were an option at the time of their death (Kaiser et al., 2014). An important thing to remember for people who are interested in it is that most people do not want brain preservation. These wishes need to be respected.
At the same time, there is a good argument that the minority of people who do want to do brain preservation, while they are often portrayed as a weird and selfish minority, should also have their civil rights and body autonomy respected. That they should be allowed to access high-quality brain preservation if they are informed about the possible risks, benefits, and alternatives and still choose to go through with it.
The information in these essays is provided for educational purposes only. This is purely an academic discussion. It is not meant to advise or recommend for anyone to do anything. I make no representations or warranties, express or implied, about the completeness, accuracy, reliability, suitability, or availability with respect to the information, products, or services described in these essays for any purpose. Any use of this information is at your own risk.
While I have described some historical information about individuals involved in cryonics and brain preservation, except where explicitly indicated, I do not claim any special knowledge about events and opinions other than what is publicly accessible. The information in these essays is true to the best of my knowledge. However, I expect that much of it is inaccurate, and any given piece of information should not be assumed to be accurate.
Reading these essays does not create a physician-patient relationship. Always consult your healthcare practitioner for any individual medical needs. Nothing in these essays is medical advice and it should not be treated as such.
The information in these essays is my personal opinion. It does not represent the opinions of the institutions I am affiliated with now or have been affiliated with in the past. It does not represent the opinions of my employer.