Cryonics As Untested Medical Procedure

A while back I did a survey of the state of nematode emulation research to try and understand what this meant for whole brain emulation. At the time David Dalrymple was very optimistic about his Nemaload project; don't know how it's going though.

For the current state of the Brain Preservation Foundation's prizes, two Reddit AMA comments by Ken Hayworth are interesting:

Alcor has not sent us any samples and is not currently participating in our prize competition. However, one of our competitor teams is 21st Century Medicine which is a leading cryobiology research lab which uses some of the same techniques as Alcor but in a controlled laboratory environment on small animals. 21st Century Medicine has published some truly amazing results including showing that rat brain slices can be brought down to near liquid nitrogen temperature, stored for weeks, and then rewarmed with near complete recovery of neuronal function. http://www.21cmpublications.com/viewpublication.aspx?id=90 and http://www.21cmpublications.com/viewpublication.aspx?id=23 They have also been hard at work producing electron micrographs of their vitrified brain tissue in order to meet the stringent requirements of our prize. Unfortunately the technical difficulties of preparing and staining their tissue for the electron microscope has slowed our evaluation but it is ongoing and I anticipate them showing very impressive results in the near future. Eventually it would be great if Alcor itself provided additional electron micrograph evidence (beyond what is already out there) demonstrating the state of brain preservation in their actual procedures. The fact that they have not produced more evidence is at least in part due to funding constraints. It would be great if some very rich person would go to Alcor and say “I will fund your operation big time but first you have to prove to me that it preserves the brain’s connectome.” This type of skeptical evaluation is where our brain preservation prize started but it has not yet reached the level of funding and interest necessary to precipitate the required action.

And on chemopreservation:

We are currently evaluating a whole mouse brain sample provided by the neuroscience researcher Shawn Mikula. This is an official entry for winning the mouse phase of our brain preservation prize. If the submitted brain proves to be as well preserved as the electron microscope images he has provides us already, then it will be sufficient to win the mouse phase. To be clear, this means that with today’s imaging technology we can verify that the precise wiring of the brain has been preserved in a state that could last for millennia. He has published a preliminary protocol for whole mouse brain preservation and staining for electron microscopy at the following link: http://www.nature.com/nmeth/journal/v9/n12/abs/nmeth.2213.html He has since greatly improved this protocol and presented the latest results at the Society for Neuroscience conference last week. All of the neuroscientist I have discussed his protocol with are very impressed at the quality of preservation of neural circuitry. His project is aimed not just at preserving a brain but is instead aimed at actually mapping the brain circuitry in its entirety using today’s electron microscope technology. His is truly exciting and groundbreaking research. His protocol is not directly applicable to something as large as a human brain but it seems there are straight forward way to adapt it to a human.

"at least some extent of memory restoration ..."

This seems like a useful criterion. I would say "all the memories of cryonauts are very likely permanently gone" which I think is stronger than "cryonics is unlikely to prevent information theoretic death".

"Who knows, maybe you can get quite close without any physically preserved brain at all."

By what ratio do you think cryogenically preserving the brain improves the chances that someone you identify with will exist in the far future?

I think the usual solution is to do those tests on animals. Vitrifying and testing a pig brain should give us enough info.

"one shouldn't damage the brain of someone who gave it to you with the expectation that you wouldn't damage it"

Definitely, but I think they would also refuse to experiment on a brain given to them without that expectation. The people at cryonics organizations don't tend to take the common-on-lesswrong view that someone cryogenically preserved is probably dead but has a small chance of actually being recoverable. To them a "cryonaut" is stll alive. For example, Alcor's website says:

Cryonics is not a belief that the dead can be revived. Cryonics is a belief that no one is really dead until the information content of the brain is lost, and that low temperatures can prevent this loss.

So while you would view it as acceptable, knowing what you were getting into, and I would view it as acceptable, given the very high chance that your brain no longer contained you, people at Alcor or CI would likely find it unethical experimentation on a still-living human.

(I don't know how old you are, but if Alcor or CI were willing to participate in a test like this it would probably make more sense to find someone already about to die so we could run it sooner.)

But we don't have the details, do we? Suppose cryonics preserves the graph of neural connections; we can look back in 10000 years and know exactly how many neurons you had, and exactly which were connected to which others. Is that enough information to revive you, or someone who's 90% identical to you? Who knows? We really have no idea.

Your point about redundancy is, I think, looking at it from the wrong angle. I would expect brain redundancy to handle random errors like "lost 2% of neurons", but the idea that we would have multiple fundamentally different mechanisms for encoding memories seems evolutionarily implausible. If we simply haven't preserved anything about, say, the thicknesses of the glial cells, or we know which synapses are present but it turns out they have different sized gaps and that's important and we can't recover that information, or any one of thousands of other pieces of brain biology that might turn out to be vital for encoding memory, then cryonics won't work.

Vitrifying it? Probably not.

That's not the mainstream position of actual scientists who study these things, at least not for the kind of procedures that cryocompanies use.

The phrase neural archaeology evokes the right kind of thinking here. Or Eliezer's reference to secure deletion.