February 20th, 2010

nadb

Thoughts on cryonic preservation & revival

This is a rather long reply to a post from ciphergoth. The question being, is it plausible that, in future, we will be able to resurrect people from their head, cryonically frozen post-mortem?

I am keenly interested in the prospect of whole-brain emulation, which strikes me as potentially plausible, with reasonable probability. For one thing, I think that this is one of the more doable routes to AI - rather than trying to build a mind from scratch, to instead try to bootstrap it by attempting to reproduce the existing biological structures.

This being the case, it begs an obvious question, as it were: once (implicit "if" here & from now on) we have WBE, then the next big desirable leap would be scanning a biological brain and running the resultant dataset on an emulation. IOW, Kurzeilian "uploading". This strikes me as a consummation devoutly to be wished.

However, I feel - as a long-ago biology grad - that the prospects for taking a complete adult brain, scanning it & getting any data out of it that is worth uploading are virtually 0. I will come back to this in a moment.

But this is starting with a living, functioning brain - albeit possibly impaired by old age, disease or trauma. (Because why would one choose to do it if alive & healthy?)

However, the prospects of doing it from a dead brain seem to me to be far closer to 0, in a Zeno's-Paradox sort of way. Once one is outside that critical 4min window of an oxygen-deprived brain, I suspect that the remaining amount of useful information drops precipitately, with every passing minute, and after 2-3x that 4min window, I suspect there isn't enough left to be worthwhile. Given some hand-waving magical technology for interpreting memories absent the consciousness that recorded them - and of course we don't know if different consciousnesses record them in compatible or even comparable formats - one might be able to retrieve some memories from a dead brain, but a mind? I doubt it.
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