gwern 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: 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.

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