Thoughts on cryonic preservation & revival

[lproven]

This is a rather long reply to a post from ciphergoth. The question being, is it plausible that, in future, we will be able to resurrect people from their head, cryonically frozen post-mortemI am keenly interested in the prospect of whole-brain emulation, which strikes me as potentially plausible, with reasonable probability. For one thing, I think that this

Comments

[ciphergoth]

First, many thanks for sharing your thoughts as a stand-alone blog post. This is exactly what my blog post about this was intended to encourage. And it meets three of my criteria at the end of the article!

So I'm hoping you'll take the fourth step, of explicitly discussing the arguments set out by cryonics advocates on the subjects you discuss - you're clearly much better placed to evaluate them than I am. For example, you say:However, the prospects of doing it from a dead brain seem to me to be far closer to 0, in a Zeno's-Paradox sort of way. Once one is outside that critical 4min window of an oxygen-deprived brain, I suspect that the remaining amount of useful information drops precipitately, with every passing minute, and after 2-3x that 4min window, I suspect there isn't enough left to be worthwhile.
I'm guessing you're thinking of ischemic damage? This issue is discussed in detail in Scientific Justification of Cryonics Practice which is the document to rebut if you're interested in this subject. Fahy's cited study on frozen and vitrified rat hippocampal slices which looked for ischemic damage in the most vulnerable regions with an electron microscope, and Safar's study of cats subjected to a full hour of global cerebral ischemia would seem to be relevant here. Does that evidence indicate to you that you've overestimated the rate of information destruction through ischemic damage?Now we are, ISTM, approaching really quite closely to 0. But taking the additional step of freezing the dead brain first, with all the damage that the process causes, and I think we can watch the decimal point recede into the distance as we're down into the 99.9 and lots more nines % probability that there is nothing left to recover.
This is a little vague - can you discuss exactly what form of freezing damage you're most concerned by? Obviously the toxicity of cryoprotectants isn't a concern for WBE unless they actually damage information.We freeze the brain, very fast, somehow without causing microfractures, cellular rupture from ice crystal formation, etc. etc., and we manage to do this within 4min of death.
Cryonics organisations claim that their current freezing and vitrification process completely avoids ice crystal formation. Some fractures are certain; for WBE, you're betting on the computer being able to match up the two sides of the fracture; it isn't obvious to me that that's an intractable jigsaw puzzle.

[reddragdiva]

Yep. Try reading some of the papers he cites and what he says about them too.

[reddragdiva]

Is it possible to go through the tedious work of rebutting it? It is the cryonicists' best shot. Ben Best even showed up on RationalWiki to defend his paper.

(This is the point at which scepticism becomes laborious.)

[reddragdiva]

That's what I thought.

[ciphergoth]

Do the search I did. AFAICT No-one has ever written a proper rebuttal to a single assertion in that paper. If you could focus on even one flaw and write it up as a top-level blog post, you would have written the best article ever written against cryonics. Please do it.

[vatine]

Stroke patients, people who'd had electric chocks across the brain (intentional or unintentional) and a plethora of relatively small compounds (lithium citrate for one).

[ciphergoth]

I did search PubMed, obviously I'm using the wrong search terms, could you point me to what you found? Thanks!

[ciphergoth]

WRT the stroke thing: this is exactly the kind of argument that deserves to be an article or a blog post. I understand if you can't be bothered, but it's difficult to properly advance the debate when so many are prepared to be disparaging and derisory in blog comments when it seems no-one prepared to properly challenge what cryonics advocates have to say.

WRT the PubMed search, here's what I find when I search for "cryonics":Nano nonsense and cryonics.
Shermer M.
Michael Shermer knew that his only technical argument in this article didn't hold water when he sent it for publication; see discussion on my blog.Cryoethics: seeking life after death.
Shaw D.

Donaldson v. Van de Kamp: cryonics, assisted suicide, and the challenges of medical science.
Pommer RW 3rd.

"He wants to do what?" Cryonics: issues in questionable medicine and self-determination.
LaBouff JP.

The iceperson cometh: cryonics, law and medicine.
Smith GP 2nd.
These articles seem to discuss not technical feasibility, but legal, ethical, and other such issues.Nuclear DNA damage as a direct cause of aging.
Best BP.

Scientific justification of cryonics practice.
Best BP.

Cryonic suspension: an Omega interview with R.C.W. Ettinger.
Kastenbaum R, Ettinger R.

The technical feasibility of cryonics.
Merkle RC.

Many are cold but few are frozen: a humanist looks at cryonics.
Harris SB.

A matter of life and death.
Ettinger R.
Ben Best is CEO of the Cryonics Institute; Ettinger invented cryonics; Ralph Merkle is on the board of Alcor; Steve Harris is also a cryonics advocate.

If you found something I didn't find, or if there's criticism of technical feasibility in some of these articles that I've missed, I'm looking forward to hearing about it - thanks!

Maybe you should try science instead of blogs.

I really don't know what I did to deserve this tone. I don't think we've met, but if you ask the other people arguing with me in this thread, they'll tell you I'm not generally stupid or unhinged. I'm doing everything I can to hear about the other side of this argument. Can we be as nice to each other as possible, please? Thanks!

[reddragdiva]

During the course of this discussion, over several blogs and a wiki, you've been fairly consistently telling the critics "can you prove it isn't true?" You behave as though you're really wedded to the idea. So of course people are going to respond as if you are.

[ergotia]

I dont see how consistently asking "can you prove it isn't true?" = really wedded to the idea. But of course, I am not a scientist. Or even a blogger.

[reddragdiva]

This is probably a reasonable start on answering your question.

[ergotia]

Any time I want to be patronised, I will come straight to you and ask - you lead the field. Otherwise, just quit it, will you?

I am familiar with the concepts of causation and burden of proof - both as a solicitor of 15 years standing and as a reasonably well educated non scientist.

[reddragdiva]

It was in response to your apparent lack of understanding as to why "can you prove it isn't true?" is an immediate fail.