Synaptic comments on Brief response to kalla724 on preserving personal identity with vitrification - Less Wrong

8 Post author: Synaptic 16 June 2012 01:28AM

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Comment author: Synaptic 17 June 2012 08:12:14PM 2 points [-]

the experiment to do is obvious

Two experiments:

a) Teach a bunch of C. elegans the tap-withdrawal reflex, freeze them, thaw them, and see if they still know it. This is what I'm assuming you were referring to. I actually don't think this is all that useful for testing the preservation abilities of cryonics. C. elegans have vastly different life cycles from humans and the ability to freeze them isn't that generalizable. See Casio's comment above: http://lesswrong.com/r/discussion/lw/d4a/brief_response_to_kalla724_on_preserving_personal/6u7e

b) Teach a bunch of C. elegans the tap-withdrawal reflex, freeze them, and do cryo-electron microscopy on them to determine the distribution and density of vesicles and receptors at the key synapses involved. Feed that data as parameters to a simulation and see whether the simulation reflects the tap-withdrawal learning experience of that particular C. elegans, as compared to controls. This will help shed light on whether personal identity is inferable from the kind of structural data that might be preserved by vitrification in human brains.

The experiment I prefer is the second. It will take time.

So why, in twenty years, has no cryonicist apparently done the experiment?

There is next to no funding for cryonics research. And massive regulations against doing animal-based experiments without government approval.

Comment author: gwern 17 June 2012 09:46:04PM *  8 points [-]

I actually don't think this is all that useful for testing the preservation abilities of cryonics. C. elegans have vastly different life cycles from humans and the ability to freeze them isn't that generalizable. See Casio's comment above: http://lesswrong.com/r/discussion/lw/d4a/brief_response_to_kalla724_on_preserving_personal/6u7e

On the contrary, I think that given Casio's comment, such an experiment constitutes powerful evidence if it finds that nematodes don't remember after freezing - evidence for falsifying cryonics.

If it finds that nematodes do remember, then by conservation of expectations of course that's only a little bit of evidence that cryonics is preserving the necessary information, but it's still worth doing. (Cryonics costs a lot, so the VoI is high.)

Comment author: Synaptic 17 June 2012 11:17:25PM 2 points [-]

There is an experiment testing something similar to this in rats. They retain their ability to navigate a maze following hypothermia. Andjus, 1956:

The differences in retention of the maze habit among experimental and control groups were very small and in no instance were they statistically significant, although there was a consistent trend towards poorer retention following hypothermia. These small differences may be functions of the technique used to reduce deep body temperature rather than of the effects of hypothermia per se.

These results are based upon observations of the behaviour of non-hibernating, homoiothermic animals. With such animals, extreme hypothermia, such as that employed in the present study, results in complete arrest of heart beat, circulation, and respiration. It also suppresses electrical activity in the brain and in our animals cerebral activity may have been arrested for as long as 13 to z hours. Within the limits of our experimental procedure we have failed to find evidence that arrest of these vital metabolic processes as a result of hypothermia produces any very serious, permanent effects on the animal's behaviour once i t has been successfully reanimated. If, as previous writers have suggested, severe hypothermia can be used to “… stop all nerve impulses in the brain momentarily …” (Gerard, 1953), our results are difficult to explain if long-term memory is dependent upon the continuous activity of the brain.

Comment author: private_messaging 20 June 2012 05:42:58AM *  1 point [-]

Yup. Subsequently for scientists there is a lot of inclination to test this (cost-benefit formula has positive term for disproof because taking money to freeze brains without memories would be unethical) while for pseudoscientists there is a lot of inclination not to test it (cost-benefit formula has negative term for disproof). The agent's approximate utility can be deduced from the actions taken, especially from those concerning collection of information or generation of hypotheses. For the most part, liars do not even possess evidence they are lying, because they never looked for such evidence; that makes them seem more honest to naive people.

Comment author: David_Gerard 17 June 2012 08:20:39PM *  2 points [-]

Yes, that first one is the experiment I thought was obvious (I was about to come back and edit my comment to detail this, but you responded first).

I think it would teach us whether freezing and reviving with learning preserved was actually possible or not. This strikes me as important and useful information. That C.elegans has some inbuilt ability to survive freezing would confound it slightly, but I still think it's a necessary thing to at least look at.

There is next to no funding for cryonics research.

That little? (I can believe it, though.)

Has this experiment, or something like it, even been postulated anywhere in the past 20 years, or is it not as obvious to everyone else as it is to you and me?

And massive regulations against doing animal-based experiments without government approval.

I really doubt the scientific exploitation of C.elegans is as hard as that would imply, compared to the numbers of mice and rats killed daily for science.

Comment author: Synaptic 17 June 2012 09:07:10PM *  2 points [-]

I think it would teach us whether freezing and reviving with learning preserved was actually possible or not. This strikes me as important and useful information. That C.elegans has some inbuilt ability to survive freezing would confound it slightly, but I still think it's a necessary thing to at least look at.

I agree it would be useful. My wording was less charitable than it should have been. Still, the second test seems more definitive.

I really doubt the scientific exploitation of C.elegans is as hard as that would imply, compared to the numbers of mice and rats killed daily for science.

True, C. elegans experiments wouldn't be hard to do.

Has this experiment, or something like it, even been postulated anywhere in the past 20 years, or is it not as obvious to everyone else as it is to you and me?

There are lots of worm people and I don't know that much about the field. For all I know the experiment has already been done.

You should be a scientist!

That little? (I can believe it, though.)

As far as I know there are currently three labs in the world researching cryonics.

1) The de Wolf's and Ben Best, researching at the lab they made, Advanced Neural Sciences. Their budget is tiny, $20,000/yr (pdf). And this seems to be almost all private. But this is the best out there.

2) Joao Pedro de Magalhaes. His lab was just funded by a public fundraiser ($12,000) to do an RNA-sequencing experiment to learn about mechanisms of cryoprotectant toxicity.

3) Brian Wowk and Greg Fahy at 21CM. They invented M22 and have done most of the useful work over the past 10 years. And even their website says,

Although our research is of great interest to those who are interested in cryonics, 21st Century Medicine is not involved in cryonics.

So, compared to most other fields there is nobody researching this. Which annoys people like Mike Darwin and Ken Hayworth so much. This could work, but we don't know, and we as a society are hardly trying to find out.

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