Choose Wisely: Practical Applications of Philosophy in the Age of Cryopreservation

There are many people who subscribe to the idea that accurately preserving the fine structure of the brain on death, having that brain scanned and discarded, and the data of that scan later used to run a whole brain emulation is essentially no different from cold water drowning followed by successful resuscitation. There is a stop, and then a start. That the same pattern is running in a completely different system, and the original is destroyed, is immaterial: the pattern is the self. The rest of us would say that this individual died permanently with the destruction of the preserved brain, and the emulation is a copy - and possibly not even a continuous, surviving, single entity, depending on the implementation.

Which of these views you or I hold is entirely unimportant right up to the point at which it is possible to preserve the brain on death and have some choice about what happens next. Since we do presently live in the era of brain preservation by vitrification or, recently, vitrifixation, whether one holds a pattern identity view (the self is the pattern) or a continuity view (the self is the pattern as embodied in this particular set of matter) can turn out to be important. The former will kill you, if you let it steer your choices. Clearly I'm not the only one who feels that pattern identity beliefs have the potential to be dangerous to those who subscribe to them, as illustrated by this article on the options for near future development of improved methods of brain preservation.

As someone who is fully supportive of the ultimate goals of the cryonics enterprise, but still views the current state of the practice with some degree of skepticism, I make a point of acquainting myself with the latest evidence regarding the quality of cryonics procedures and their ability to preserve the foundations of a person's identity through time. Over the past two years or so, I have increasingly seen a recent achievement by 21st-Century Medicine (21CM) cited by some cryonics supporters as demonstrating the scientific validity of those procedures: namely 21CM's research on aldehyde-stabilized cryopreservation (ASC). This new technique has allowed them to win the Technology Prize awarded by the Brain Preservation Foundation (BPF) by demonstrating excellent preservation of brain ultrastructure. Were I to follow this line of reasoning, I could happily set aside my concerns about the adequacy of today's cryopreservation procedures, which had now been verified by scientific experts; the proper focus would now need to be on how to responsibly introduce those procedures into a clinical setting, for patients at the end of their lives who might request them.

It turns out, however, that things are not so simple. ASC is no doubt a step forward for the field of brain banking, and as its name indicates, it it is indeed a form of cryopreservation, since it involves vitrification of the brain at -135°C. Nonetheless, ASC does not count as cryonics, insofar as it uses a fixative solution prior to vitrification and cooling, which could potentially preclude revival of the original biological brain (an essential part of cryonics as traditionally understood). And indeed, biological revival with the help of future technology is not a priority for the Brain Preservation Foundation (BPF)'s president, Dr. Kenneth Hayworth. Rather, he envisages brain preservation as conducive to life extension via mind uploading: a process that would involve cutting the preserved brain into thin slices, scanning each slice, and feeding the resulting data to an advanced computer that would thereby be able to map out the entire network of neural connections in the person's original brain, and ultimately to emulate that person's mind. This is quite different from cryonics.

The BPF's commitment to holding brain preservation research to the highest standards of scientific rigour is laudable, and worth emulating. Nonetheless, for those interested in brain preservation with a view to enabling life extension, supporting cryonics-specific research remains the safer bet. We should not simply rely on the BPF's approach if our goal is to try and save those whom medicine in its current state cannot restore to life and health.

To see why this is so, let us begin by noting the two main philosophical theories of personal identity through time that are relevant when discussing the respective merits of cryonics and mind uploading in this context. The first one, which we can call the "Physical Continuity" (PhyCon) theory, asserts that a person is identical with the physical substratum from which her mind emerges: that is to say, her brain, with its intricate web of neurons and synaptic connections. The second relevant theory can be referred to as the "Psychological Continuity" (PsyCon) theory. Roughly speaking, it says that you are to identical with the set of psychological features (memories, beliefs, desires, personality traits, etc.) that constitutes your mind. On this view, preserving you after you have been pronounced dead requires ensuring the persistence of enough of those psychological features, in an embodied mind of some sort (but one that need not be embodied in your current biological brain).

If that is the case, what is the prudent choice to make for those who wish to promote life extension through brain preservation? I submit that traditional cryonics is the more prudent option to pursue. This can be demonstrated using a simple argument that considers what the implications are if we assume that PhyCon and, respectively, PsyCon are true. Suppose first that PhyCon is true. If so, a cryonics procedure carried out properly will save a person's life, whereas using a technique like ASC that compromises the brain's potential for viability, followed by destructive scanning and uploading, will kill that person. If PsyCon is true, on the other hand, both methods can ensure survival. Indeed, adequate cryonic preservation of a person's brain would also preserve the ultrastructure grounding the various psychological features that defined that person.

None of this is meant to imply that the work of the BPF is without merit. On the contrary, the Foundation's approach demonstrates a number of virtues that can provide a model for the cryonics movement to follow. These include a commitment to rigorously and impartially evaluating the quality of brain preservation procedures, in accordance with the standards of scientific peer-review. Another example is the BPF's successful effort at crowdfunding its incentive prizes for brain preservation research, such as the two prizes won by 21CM.



The continuity view has the advantage, even if it's wrong, that it's the safest bet. You lose nothing if you adhere to it, but you can lose your life if you choose the pattern view and finally it's wrong.

Posted by: Antonio at March 16th, 2018 8:44 AM

I think mind uploading is a fantasy. Emulating a brain (a personality) on computational devices is not likely for a very long time, if ever. The issue is the complexity of neurobiology and the difficulty of simulating it all using computing technology. I'm not sure it can be done using computers. Direct biological survival is necessary.

Posted by: Abelard Lindsey at March 16th, 2018 9:51 AM

I sure hope the "mind-uploading" crowd doesn't think that it will be them. After all, if you upload multiple times, you're just copying the mind.
The fact that multiple copies could simultaneously exist seems to completely rule it out.

Posted by: bmack500 at March 16th, 2018 1:13 PM

> The fact that multiple copies could simultaneously exist seems to completely rule it out.

I disagree. I've read sci-fi novels where the protagonist uses a time machine to visit his former self. In such a case there are two copies that exist simultaneously and they are both the same person without any conflict. The case of mind-uploading is more complicated since both personalities will develop differently but they will start out as the same one.

I guess the different viewpoints are based in different views on people. While some people see persons more as living objects others see a personality as a living process. Much like music or software - a copy of a song is still the same song.

Posted by: Matthias F at March 16th, 2018 2:33 PM

If the result of vitrification was as good for the mind-uploading scenario as what 21CM produced through vitrifixation, then the argument in the article would hold. But if that were the case, then vitrification would have won the BPF prize a while ago.

If some quality threshold for maintaining the structure of the dendrites is needed for the mind-uploading case to work, and vitrification doesn't reach it, then vitrification doesn't satisfy the "PsyCon" branch.

Posted by: ale at March 16th, 2018 6:24 PM

"If the result of vitrification was as good for the mind-uploading scenario as what 21CM produced through vitrifixation, then the argument in the article would hold. But if that were the case, then vitrification would have won the BPF prize a while ago."

No. As the article says:

1) Vitrification produces a reduction in size of the brain. That makes the conectome more difficult to see, more distorted and twisted, but it doesn't mean it's broken.

2) Vitrifixation produces better contrast through the microscope and so the structure is easier to see. That also doesn't mean that the structure is worse preserved.

Both make the prize easier to win but don't affect uploading.

Posted by: Antonio at March 17th, 2018 1:07 AM

We do not know how much information we need to keep to make uploading work. We do not know if the connectome is enough. We might need to know a quite precise geometry of each synapse. To be on the safe-side, the more accurate the mapping, the better. See Sandberg and Bostrom's roadmap for a whole lot more on this:

Posted by: ale at March 17th, 2018 1:36 AM

Ale, there are numerous suggestions that the connectome is not enough. Brain states depend on e.g. the levels of neurotransmitters and other chemicals and possibly the electric fields due to missing/additional electrons. The same connectome with different amounts of neurotransmitters results in different personalities, which is why psychoactive pharmaceuticals can be helpful. This is the major practical problem of the pattern identity view: we don't know what constitutes the pattern. Details of your endocrine system may very well be necessary to be able to use your connectome to reproduce /you/, in which case they are a part of the pattern and they need to be stored as well.

Posted by: Ivo at March 17th, 2018 4:35 PM

This method is quite different from the way Alcor preserves brains and in my opinion superior, but Erier the author of the quote doesn't like it for philosophical reasons that I have to say seem downright silly to me. Basically what they did is fix the molecules in place with glutaraldehyde (the stuff in the wart removing lotion you can get at the drugstore ) then they infused ethylene glycol as a cryoprotectant and then cooled the brains down to -135 C where they became vitrified. After rewarming the brains were examined and "show exquisite preservation of anatomical detail after vitrification and rewarming, with virtually no identifiable artifacts relative to controls."

So can Alcor's method match that? Erler says he doesn't know because with Alcor's method "the brain shrinks to almost 50% of its natural size due to osmotic dehydration hindering our ability to establish the quality of ultrastructure preservation". Well yes, I imagine such shrinkage would distort things and make it harder to see fine details, McIntyre and Fahy think so too:

"For the purposes of connectomics, this dehydration is undesirable because it distorts the brain's ultrastructure and causes difficulties in tracing fine​ neural processes. "

But there is no shrinkage with the new method. After keeping the brains at -135 C for several days they then rewarmed them and examined them with a electron microscope. This is what they found:

"Rabbit brains upon dissection revealed no cracks resulting from the vitrification or rewarming processes. Brain weights were commensurate with control brains, and we found no retraction of the brains from their skulls. Control rabbit brains displayed excellent ultrastructural preservation. [...] All 8 rabbit brains preserved using ASC consistently displayed ultrastructural preservation indistinguishable from that of controls [...] Intracellular organelles are also well preserved: rough endoplasmic reticulum is clear and compact, and the mitochondria appear normal [...] There are several synapses present, with clear pre-synaptic vesicles and well defined, darkly stained post-synaptic densities [...] All capillaries are open and clear of debris, there are no ''dark'' cells, and there is no obvious mechanical or osmotic disruption or distortion of any cells. [...] We also observed no signs of ice crystal artifacts in any of our ASC-processed brains. [...] . Vitrified storage at -135 C should enable essentially indefinite storage of brain tissue with no degradation due to suppressed molecular motion in the vitrified state. [...]The aldehydes immediately stabilize the fine structure of the brain to an extent sufficient for connectomics research, meeting our goal of high-quality preservation. [...] ASC is scalable to because the chemicals are delivered via perfusion, which enables easy scaling to brains of any size; vitrification ensures that the ultrastructure of the brain will not degrade even over very long storage times, processes were easily traceable and synapses were crisp"

So much for that old canard about a frozen brain resulting in mush. It seems pretty clear to me that the ASC method is better at preserving brain information and Alcor should switch over to it unless financial reasons make it impractical, and I don't think wart lotion is all that expensive. But the thing that bothers Alexandre Erler is not the expense but the fact that although the information about the brain is preserved the fixative would render the brain itself unviable, it would be easier to use the information to make another brain (or upload the brain software) than it would be to remove all the molecules of glutaraldehyde from the original brain so it can be restarted. Erler fears that the duplicate brain might not *really* be you even if all the information in both was identical, he wants to keep the "original" brain.

But what exactly is so original about the "original"? Atoms are generic, our names are not scratched on ​the atoms in our bodies​, not even ​on ​the atoms in our brain. And besides​,​ atoms are constantly shifting in and out of our bodies anyway, today your brain is literally made of last years mashed potatoes. It seems to me if we are going to have any chance of escaping oblivion we need to totally embrace rationality​,​ and that means we should go for whatever method that best preserve brain information regardless of what happens to "the original". Cryonicists often criticize others for failing to be rational about life and death, but with talk about "the original" and a immaterial "something" that a copied brain would lack we are doing the same thing; if we're going to go down that road we might as well abandon science altogether and stick with traditional religion and hope that mumbo jumbo will bring us immortality.​ I agree 100% with ​McIntyre and Fahy​ that we don't ​"need to preserve the biological viability of brain tissue; the primary criterion for success is instead to maintain the delicate​ ​ultrastructural appearance of the brain​"​.​

​John K Clark​

Posted by: john Clark at March 26th, 2018 8:14 PM

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