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

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

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (32)

You are viewing a single comment's thread. Show more comments above.

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.