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June 22, 2012

Plastination for Preservation of Brain Information Needs $45,000

An anonymous donor has funded a $100K Brain Preservation Prize, paid to the first team(s) to pass this test on a human brain, with a quarter of the prize going to those that first pass the test on a mouse brain. Cryonics and plastination teams have already submitted whole mouse brains to be tested. The only hitch is that the prize organization needs money (~25-50K$) to actually do the tests.

Economist Robin Hanson has donated $5000 towards the testing of plastinated whole mouse brains.

The Brain preservation prize is a cash prize for the first individual or team to rigorously demonstrate a surgical technique capable of inexpensively and completely preserving an entire human brain for long-term (over 100 years) storage with such fidelity that the structure of every neuronal process and every synaptic connection remains intact and traceable using today’s electron microscopic (EM) imaging techniques.



This prize competition is structured into two Stages:

Stage 1- Preservation of an entire mouse brain (or similar small mammalian brain) using a technique that is applicable to a laboratory environment.

Stage 2- Preservation of a large mammalian brain (a pig for example) using a surgical technique meeting all the medical standards necessary for it to be applied (as an elective procedure) to a human patient in a hospital setting, and using a procedure that, with minor modifications, might potentially be offered for less than US$20,000 by appropriately trained medical professionals. The first group to complete Stage 1’s requirements will win 1/4 of the total prize purse accumulated up to that date. The first group to complete Stage 2’s requirements will win the remaining prize purse, or the entire prize purse if no one has previously met Stage 1’s requirements.

Plasination replicates preserving in Amber

Biological samples have been accidentally preserved from the deep past through dehydration, freezing, anoxia, and chemical preservation; ancient DNA has (possibly) been recovered from 250 million year old salt crystals, 23 million year old insects are classifiable and preserved in high fidelity, and ice samples have preserved 800,000 year old and 400,000 year old DNA. 38,000 year old Neanderthal DNA has been partially recovered & sequenced, as has 28,000 year old woolly mammoth DNA. 30,000 year old frozen plant tissue has been grown into healthy adult plants. One 4000 year old human genome was sequenced. Many of the samples chemically preserved in amber turned out to be contaminated mistakes, but nevertheless, the preservation is very good and down to the cellular level.

Summary of where we are with Plastination from Robin Hanson

Brain research techniques have now reached two key milestones:

1. They’ve found new ways to “fix” brain samples by filling them with plastic, ways that seem impressively reliable, resilient, and long lasting, and which work on large brain volumes (e.g., here). Such plastination techniques seem close to being able to save enough info in entire brains for centuries, without needing continual care. Just dumping a plastic brain in a box in a closet might work fine.

2. Today, for a few tens of thousands of dollars, less than the price charged for one cryonics customer, it is feasible to have independent lab(s) take random samples from whole mouse or human brains preserved via either cryonics or plastination, and do high (5nm) resolution 3D scans to map out thousands of neighboring cells, their connections, and connection strengths, to test if either of these approaches clearly preserve such key brain info.


Cryonics Calculator of Successful preservation and revival

1. Likelihood of getting preserved
2. * preservation contains needed information
3. * information’s survival over the centuries until revival possible
4. * existence of organizations or entities arranging revival
5. * the actual revival

Advantage for plastination:

1. Improves survival parameter #3: It is probable that scanning technology will outstrip upload technology. In many fields, the ability to gather data exceeds the ability to process or understand it. Hence, it is possible and quite likely that during the long wait for revival, it will become possible to scan a plastinated brain in sufficient resolution to eventually upload it.

Even if the scan were destructive, such a scan would make it possible to drastically increase survival odds by copying the digital data to many archives and formats online and offline. No such option is available to a cryonics brain unless it abandons cryonics entirely, in which case why did it take the risk of the cryonics failing & it warming up rather than be plastinated from the beginning? It’s hard to imagine the benefits being so equally balanced that the actualization of better scanning would is enough to change the plans - given how many parameters there are, a ‘pure’ strategy of 100% cryonics or 100% plastination will win. (Indeed, one might wonder how one would know that a plastination+scanning procedure was good enough for uploading in the absence of a successful human upload. Human biology often diverges from even close animal models, and shouldn’t we expect things like consciousness to be even less reliably modeled by those animal models? The window between the first successful upload and widespread uploading will be short compared to the time between now and then, even if you assume no Singularity of any kind, not even Robin Hanson’s Crack of a Future Dawn, and a slowed-down Moore’s law.)

2. Improves organizational parameter #4: Plastination may be such a technology. It does not require organizational continuity; one rough year and your brain is a pile of rotting maggots with cryonics. one rough year with plastination, and your brain is a bit dusty. A plastinated brain doesn’t even need an organization: it may be preserved as a time capsule, a family heirloom, a curiosity, or perhaps just buried somewhere; but a cryogenically stored brain must have a sophisticated support system which will supply it regularly with liquid nitrogen, and that rules out pretty much everyone but a cryonics organization. Mike Darwin has been a real wake up call - the Outside View says ALCOR and CI are much more risky than usually assumed - and indeed, one cryonics organization has already failed with the loss of patients. Past the century mark, a few percent is the highly optimistic estimate! Cryonics organizations have done reasonably well, but ALCOR consistently runs at a loss and if membership does not follow an exponential growth (as it does not), then relatively soon the ratio of dead members to live members will start getting much worse.

3. Improves likelihood of preservation #1: Much cheaper than vitrification; while cryogenic storage is very cheap in scale the cost is still non-trivial for the foreseeable future.

4. Improves revival parameter #5:

1. despite being a relatively young field (albeit respectable & well-funded), plastination & scanning has made tremendous progress and is slowly being automated, with one human brain sliced at 70 micro thickness and photographed, or producing partial connectomes7 of brains. One might characterize the two fields as: connectome:upload::revived-rabbit-kidney:functioning-brain, and ponder the following possibilities:
* (=) If one regards the ‘distance’ between the state of the art and the goal as equal, then plastination’s faster progress is a win
* (<) If one regards the distance as smaller for plastination than cryonics, then plastination wins both on faster progress and how much is left to do * (>) Only if one regards the kidney as being much closer to a reviving a functioning brain can it be possible for cryonics revival to beat plastination revival.

Pondering the Roadmap and the Blue Brain project, I strongly doubt the kidney-brain is much closer together than connectome-upload, and suspect that the latter is closer.

2. If plastination turns out to be the ‘right’ starting point for an upload and cryonics brains must be plastinated first, we might expect the cryonics->plastination process to be more lossy than recently-deceased-brain->plastination process. It could be that warming the brain up enough to plastinate does damage, or that the cracks caused by vitrification are not reparable and degrade the plastinated result.

Disadvantages

1. Threatens information preservation parameter #2 in several ways:

* can plastination preserve the level of detail required for reconstruction? Unknown. The Brain Preservation Technology Prize is attempting to spark research.
Cryonics assumes, based on analogous near-death experiences, that many things like dynamic electrical activity, can be disregarded for the purpose of personal identity. Plastination is known to preserve overall neural structure in high resolution, as evidenced by current plastination techniques sufficing to create connectomes, but what does it miss? It misses the dynamic activity, like cryonics, but cryonics preserves things plastination may not. Does plastination preserve neurotransmitter levels? (It seems inconsistent with the general idea of plastination.) Neurotransmitter levels change endlessly, but levels of neurotransmitters can be the difference between sanity and insanity in the living; on the other hand, personal identities persist even through careers of massive head trauma like boxing or football, which affect neurotransmitters (see Fencing response).

What might we be missing?
* are the methods well-studied and implemented even if they are capable in principle of preserving the necessary information? They have been widely used in neuroscience, but there are no checks or ‘round trips’ showing that information and functionality is preserved with normally executed techniques - at least cryonics has frozen rabbit kidneys to test itself on, what does plastination have?
Counter-point: brain scanning and the associated plastination techniques are an extremely hot field of research, which is improving at an amazing clip akin to DNA sequencing. This ought to give us considerable confidence in its current and future techniques. (This also raises an interesting point that anyone not dying in the next decade or two is wasting their time by investigating plastination. It’s entirely possible that for a young or middle-aged person, the field will either have succeeded in plastinating an animal or human brain and then uploading it, or will have dead-ended and the fundamental limits discovered, by the time they truly need to choose between cryonics and plastination.)

3. Are the plastination processes fast enough? Normal brains are preserved over weeks to years, which is strictly worse than a hypothetical equally good process which requires hours. Cryogenic cooling appears to be intrinsically faster than chemical diffusion and action. How much damage does the extra time required do? (There’s some weak evidence that the rate of degradation is somewhat constant and hence the damage linear over time.)


2. Threatens revival parameter #5: a vitrified brain can, presumably, be plasticized if necessary. However, a plasticized brain is permanently plasticized. The plasticized brain has only 1 option. A vitrified brain has 2 options: normal freezing and repair (whatever that will be), and the plasticized route (scanning and upload, likely). A disjunction of two probabilities is at least as likely as either disjunct. Ease of revival also affects how long storage must succeed - if revival is feasible for both, but cryonics is easier, the cryonics brain will have to last a shorter period than the plastinated brains. (This cuts both ways: if plastinated brains are easier to revive or upload, then it will be the cryonics brains which lose some probability due to the increased wait-time.)

This may not be a large advantage for cryonics. Most cryonics advocates seem to expect uploading will be the ultimate solution, inasmuch as brain scanning is advancing a lot faster than medical nanotechnology (see the Whole Brain Emulation Roadmap), but there’s still a small probability that a non-upload organic solution will be used, and this small probability is forfeited in the plastination route.



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