More Cryonics Probability Estimates

It would have been interesting if they had done a third group and added spurious categories (probably wouldn't work with experienced mechanics) and/or broke down legitimate categories into many more sub categories than necessary. What would that have done to the "other problems" category?

...it would be really nice if someone had bothered to actually check statistics on how many car failures were actually due to each of the possible causes.

Is subadditivity a one-way ratchet such that we can reliably infer that people are wrong to be more optimistic about cryonics after seeing fewer failure steps?

This sounds wrong to me. In full generality, I expect breaking things into smaller and smaller categories to yield larger and larger probability estimates for the supercategory. We don't know what level of granularity would've led mechanics to be accurate, and furthermore, the main way to produce accuracy would've been to divide things into numbers of categories proportional to their actual probability so that all leaves of the tree had roughly equal weight. Your question sounds like breaking things down more always produces better estimates, and that is not the lesson of this study.

If I was trying to use this effect for a Grey Arts explanation (conveying a better image of what I honestly believe to be reality, without any false statements or omissions, but using explanatory techniques that a Dark Arts practitioner could manipulate to make people believe something else instead, e.g., writing a story as a way of conveying an idea) I would try to diagram cryonics possibilities into a tree where I believed the branches of a given level and the leaf nodes all had roughly equal probability, and just showing the tree would recruit the equal-leaf-size effect to cause the audience to concretely represent this probability estimate.

Can you clarify whether the following is correct? "The study shows that domain experts add less weight than non-experts to 'other' when important categories are removed."

Accessing long term memory appears to be a reconstructive process, which additionally results in accessed memories becoming fragile again; this is what I believe is occurring here. The learned aversion is reconstructed and as then susceptible to damage much more than other non-recently accessed LTM. Consider that the drug didn't destroy ALL of the mice's (fear?) memories, only that which was most recently accessed.

So no worries to cryonics!

simply long-term structural changes in the brain to seeing memories as the products of "continuous enzymatic activity"

Long-term structural maintenance requires continuous enzymatic activity. For example, the average AMPA receptor lasts only around one day: http://www.ncbi.nlm.nih.gov/pubmed/18320299. The actin cytoskeleton, made up of molecules which largely specify the structure of synapses, also requires continuous remodeling. If a structure is visibly the same after vitrification (not trivial), that means the molecules specifying it are likely to not have changed much.

This is a clear assertion that there aren't even any correlates of that information preserved, if kalla724 has already thought the correlates argument through. It's not clear to me whether or not they have.

Note useful discussion today by wedrifid and Eliezer, arguing that kalla724's comments clearly suggest that they haven't. I got the same vibe, but my knowledge of the relevant science is so spotty that I didn't want to make a confident prediction myself.

This seems like a good place to inject a related point. One of the failure modes listed is

Reviving people in simulation is impossible.

The contrary of which is: Reviving people in simulation is possible. But there is also this possibility to consider: Reviving people in the flesh is possible. So it would seem that we need to branch here, and then estimate the combined probability after assessing each branch. Maybe P( possible in-flesh | impossible in-simulation) is very small, and this branch can be safely ignored. I haven't looked for other branching points, but I don't feel assured that there aren't more.

The cost of life insurance scales with your risk of death in the covered period: if cryonics is rendered redundant then you can stop paying for the life insurance (and any cryonics membership dues) thereafter.

Redundancy would be a significant worry if, counterfactually, you had to pay a non-refundable lump sum in advance.

Two other potential forms of redundancy:

• Future civilizations have the power and motivation to restore even people who were simply buried

• Everything you ever coherently wanted to get out of cryopreservation can be achieved by a cheaper method, e.g. having children

I don't think the first point has significant probability, but I'll throw it out there in case it inspires someone to find more possibilities I've overlooked.

If the alternative is between saving for retirement and cryonics then for a lot of probability mass of cryonics being redundant nanotech or time travel has made us extremely rich perhaps reducing the cost to us of having not saved (although interest rates might have been high, still you can check for this along the way). For much of the probability mass of cryonics not working, our species has gone extinct (and not in a good way) eliminating the value of money and the harm of not having saved as much as you would have had you not done cryonics.

I'm an Alcor member.

There's another effect of "unpacking", which is that it gets us around the conjunction/planning fallacy. Minimally, I would think that unpacking both the paths to failure and the paths to success is better than unpacking neither.

Also, yon neuroscientist does not understand the information-theoretic criterion of death.

They appear to, they are questioning whether current cryonic practice preserves said information at all - they are saying it will destroy it.

as you divide larger categories into smaller and smaller subcategories, the probability that people assign to the total category goes up and up

The idea that when people disagree over complex topics that they should break their disagreement down is one I've learned in part from Robin Hanson and in fact he applies it cryonics

While Robin has fewer categories, if you look at the detailed probabilities that people gave we could throw out most of their answers without changing their final numbers; people were good about saying "that seems very unlikely" and giving near-zero probabilities. Most of the effect on the total comes from a few questions where people were saying "oh, that seems potentially serious". If I do this more I'll fold many of the less likely questions into more likely ones (mostly so I get a shorter survey) but I don't think that will change the outcome much.

I would expect unpacking to work for two reasons: to help avoid the planning fallacy and to let us see (and focus on) the individual steps people most disagree on.

unpacking all the disjunctive paths to success into finer and finer subcategories

As far as I can tell there's really only one path to success, and it's the one I put here. In my reply to torekp I talked about why I thought in-the-flesh revival was enough less likely not to matter. What would you put as disjunctive paths where "you sign up to get frozen and start playing for it" makes the difference is you being revived?

If any disjunctive paths are serious enough I'm willing to go back and add them to my model.

EDIT retracted: "looking up the Subadditivity effect I think your claim is just wrong. If anything breaking larger probabilities down makes for larger combined probabilities". [This was wrong because I was confusing the negative and positive formulations. Robin Hanson's is positive (which subadditivity should push in the 'cryonics-likely' direction) while mine was negative (which subadditivity should push in the 'cryonics-unlikely' direction).]

I could equally make cryonics success sound almost certain

I'd be interested to see someone do that.

There are a lot of variants on this exercise that could be studies in bias. The five of us doing this estimate on the bus, for example, realized that our answers came out clustered while Jeff's was far away because we had done it together. For each individual question we were supposed to think of our own answer before anyone spoke, to avoid anchoring. But we were anchored by the answers the others had given to all the previous questions.

To me this just looks like a bias-manipulating "unpacking" trick - as you divide larger categories into smaller and smaller subcategories, the probability that people assign to the total category goes up and up.

How do you know the raised estimate with this "trick" is worse than the estimate without?

I could just as easily say, "As you merge smaller categories into larger and larger categories, the probability that people assign to the total category goes down."

'Subadditivity effect'

Whether C. elegans can be uploaded with particular memories and/or behaviors has no bearing on whether human personal identity is preserved, since the C. elegans nervous system is completely identified - every C. elegans brain grows identically to every other C. elegans brain, so there is no structural wiring differences between one C. elegans and another. "Memories" (better thought of as stimulus-based behavioral divergences in something so small) are not encoded in the C. elegans' neural pattern at all, the way they are encoded in the human brain; they're merely held in a sort of 'active loop' of neurochemical feedback mechanisms.

It's certainly possible that the same sort of thing happens with human brains, but on a much more complex scale - but it definitely seems true that human brains actively re-wire our neural interconnections in a way that C. elegans doesn't.

What is the chance that some other means are found of simulating your personality without physical access to your brain (preserved or otherwise)?

It probably depends on how faithful a copy you'd be contented with, as well as on how much evidence about you you leave behind (writings, internet posts, other people's memories, etc. -- lifelogging being the extreme version).

I wouldn't, because a simulation of me is effectively a copy, and having a copy lying around would not keep me from dying. It's not like I know a huge number of people would be thrilled at having a simulation of me to interact with (and probably annoy, hehehe). Having a simulation of me while I'm still alive, though, would probably come in handy, so it's not an idea to which I am opposed. I just don't see it making anything with a chance of preserving this instance of me redundant.

(2) I'm not sure whether I should generalize to much of LW, but when people talk about extracting information from the brain, the plan is not repair, but to make a new brain, whether physical or in simulation. Making a new body is very cheap compared to this.

(1) Simulating hormones is important, but is there any information there to preserve? If the brain controls hormones, then there is no information outside the brain. Of course, it doesn't control them directly, but mediated by glands that probably have different responsiveness in different people; certainly in people with glandular tumors. But there are just a few parameters to determine, basically average levels for that person. Testing different levels for a person would be like giving them external hormones. This changes people's personalities, but only temporarily. Thus it does not appear that much long-term information is stored in hormone levels. In principle the glands could do lots of information processing, but I don't think that there's any reason to believe that. However, the spinal column is made of nerves, which we do know are all about information processing, so it is likely that some information is stored there.

but another large part of it is mediated by hormones going to and from the rest of your body

http://en.wikipedia.org/wiki/Hypothalamus

Poking at deathtimer I'm not sure it's adjusting for "you've already lived to age X". It says I'll probably live to 77 which is pretty close to what this table has for my life expectancy at birth.

"Brain degradation after death" is the key point in this list that I'd be interested in learning about. I'm not sure if it's proper to ask this in a comment now or should I be studying diligently around the issue, but I think it's also an interesting subject so excuse me.

Yes, good intuition. This is what Mike Darwin considers the largest problem in cryonics: http://chronopause.com/index.php/2011/02/23/does-personal-identity-survive-cryopreservation/

I would already be signed up for cryonics if I only had the money for that

I hear it's common to overestimate the cost of cryonics. Have you actually checked on the prices? If not, it may be lower than you think.

Full disclosure: I am not signed up for cryonics.

Replying to my own question: Xachariah made a more detailed argument about a similar issue, a while back.