[ExI] [Extropolis] Crosspost

[Keith Henson]

On Sat, Apr 19, 2025 at 10:47 AM John Clark <johnkclark at gmail.com> wrote:
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> Yes. The wiring diagram is necessary but not sufficient, but I think it's a reasonable extrapolation to say that if a frozen brain that has been infused with cryoprotectant and ASC does a better job at preserving wiring information than a brain that is infused with cryoprotectant alone (and we have strong evidence that it does) then it probably does a better job at preserving synaptic weights too.

You might be right.  It's my opinion that crosslinking all the
proteins in a synapse would make examining them harder, possibly
impossible.  But that's just my opinion.

>> > Your case would be much improved if you could show that memory could be recovered from a scanned brain slice.
>
> I am not suggesting that ALCOR should start slicing up the brains of their frozen patients, but I am suggesting that those brain slices provide powerful evidence that ASC plus cryoprotectant scrambles information less than cryoprotectant alone does. The exact method Mr. Jupiter Brain chooses to extract that information I don't know so I will leave that to His discretion, He will know much more about that than I do, although I'm certain Nanotechnology will be involved, and I think it would be wise to do everything we can to make His job easier.
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>> >  I suspect that uploaded humans will find that state more desirable than the physical state
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> Then why did you say you had no interest in uploading if it required a destructive scan?

I don't like destroying original material.  There is no reason I can
see that uploading should not be reversible.  Destroying the original
makes this no longer an option.

Keith


> John K Clark    See what's on my new list at  Extropolis
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> jaa
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>> > > We know for a fact that ASC preserves the synaptic neural connections in the brain better than the procedure ALCOR currently uses because today we can detect those connections if ASC is used but cannot do so with ALCOR's procedure. We have some reason to be hopeful that ALCOR's procedure also preserves that information and it's just scrambled up more, but we do NOT know that for a fact. And why make things more difficult for future technology to bring us back if that difficulty can be avoided?
>>
>> > Do you have any pointers to ASC preserving synaptic information?  That
>> would be very interesting, essentially reading out memory.  As far as
>> I know (and I may be out of date) they can see synaptic nodes, but
>> pictures do not disclose the weighting of a node.
>>
>> This is what ALCOR had to say about ASC back in 2018 and as far as I know they haven't said anything about it since:
>>
>> > "A new cryobiological and neurobiological technique, aldehyde-stabilized cryopreservation (ASC)  provides strong proof that brains can be preserved well enough at cryogenic temperatures for neural connectivity (the connectome) to be completely visualized. [...] Current brain vitrification methods without fixation lead to dehydration. Dehydration has effects on tissue contrast that make it difficult to see whether the connectome is preserved or not with electron microscopy. That does not mean that dehydration is especially damaging, nor that fixation with toxic aldehyde does less damage."
>>
>> > ALCOR's position on brains preservation
>>
>> > I would maintain that the last sentence in the above is factually incorrect. ASC DOES cause less damage than ALCOR's current method. That's why we are able to trace the neural connections with today's technology with one method but not with the other. The damage caused by ALCOR's method may not be irreplaceable, the information may just be scrambled more than it is with ASC and require Mr. Jupiter Brain to jump through more hoops to recover it, but maybe not, so why take the chance?
>>
>> >>> >> we are both ALCOR clients and if we're lucky enough to be revived I don't think we will have much say about how it was done.
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>> >> > You can write specifications into your contract.  One Alcor patient
>> >> is/was blind.  He specified that he is not to be revived until the
>> >> procedure can give him sight. But you are essentially correct.
>>
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>> > That seems unnecessary, if the future people have the technology to repair a freeze damaged human brain they certainly have the technology to restore his sight.
>>
>> It is not a matter of restoration, the patient was blind from birth.
>> He was one of those blinded by preme oxygen treatment.
>>
>> >I wrote no specifications in my ALCOR contract because I thought it unlikely that anybody would pay attention to them and if they did they might turn out to be counterproductive because I have only a hazy understanding of what the post singularity world will be like. For example, if somebody wrote that they do not wish to come back as an upload and that request was honored I don't think Mr. Jupiter Brain would bring him back at all.
>>
>> Possible.  However, I think repairing brains/bodies is on a par with
>> uploading.  I suspect that uploaded humans will find that state more
>> desirable than the physical state, leading to a population collapse.
>>
>> Keith
>>
>> > John K Clark   See what's on my new list at  Extropolis
>> >
>> >> >> > More cell damage occurs during the thawing process than the freezing process, and if ASC chemical fixation is used there is no brain shrinkage and the synaptic connection information is preserved; we know this because beautiful electron microscopic pictures have been taken of brain cells preserved in this way. Then the frozen brain could be disassembled from the outside in, one very thin layer at a time, and the information about where and how strong all the synaptic connections in that layer could be recorded, and then work could start on the next layer and you keep going until there is nothing left of the brain.  After all the information in all 10^14 synapses have been recorded that information is later translated into electronics and the uploading has been completed.
>> >> >> >
>> >> >> > OK OK I admit the above scenario may seem like a crazy fantasy but it should be remembered that, unlike perpetual motion or faster than light spaceships or traveling to the past, it does NOT need to invoke new science to become a reality, all it needs is improved engineering.
>> >> >> >
>> >> >> >> > I also doubt that ET beings create mega-structures or planet sized computers or brains.
>> >> >> >
>> >> >> >
>> >> >> > I too think ET is very unlikely.
>> >> >> >
>> >> >> >>
>> >> >> >> > If it does happen it might be in one out of a trillion galaxies. It will not be done by us. I suspect we will be off the Darwinian game table in the rather near future.
>> >> >> >
>> >> >> >
>> >> >> > I very much doubt biological humans will still be around a century from now and perhaps not a decade from now, but I have some hope that Mr. Jupiter Brain will have at least a little affection for us, after all He wouldn't exist except for us, so maybe He will give us access to a small (by His standards) server so that a few billion uploads can be run in a pleasant virtual world.