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Vladimir_Nesov comments on Neil deGrasse Tyson on Cryonics - Less Wrong Discussion

6 Post author: bekkerd 09 May 2012 03:17PM

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Comment author: kalla724 12 May 2012 09:58:56PM 54 points [-]

Ok, now we are squeezing a comment way too far. Let me give you a fuller view: I am a neuroscientist, and I specialize in the biochemistry/biophysics of the synapse (and interactions with ER and mitochondria there). I also work on membranes and the effect on lipid composition in the opposing leaflets for all the organelles involved.

Looking at what happens during cryonics, I do not see any physically possible way this damage could ever be repaired. Reading the structure and "downloading it" is impossible, since many aspects of synaptic strength and connectivity are irretrievably lost as soon as the synaptic membrane gets distorted. You can't simply replace unfolded proteins, since their relative position and concentration (and modification, and current status in several different signalling pathways) determines what happens to the signals that go through that synapse; you would have to replace them manually, which is a) impossible to do without destroying surrounding membrane, and b) would take thousands of years at best, even if you assume maximally efficient robots doing it (during which period molecular drift would undo the previous work).

Etc, etc. I can't even begin to cover complications I see as soon as I look at what's happening here. I'm all for life extension, I just don't think cryonics is a viable way to accomplish it.

Instead of writing a series of posts in which I explain this in detail, I asked a quick side question, wondering whether there is some research into this I'm unaware of.

Does this clarify things a bit?

Comment author: Vladimir_Nesov 13 May 2012 08:43:48PM *  7 points [-]

The point you're making seems to be that performing the repair is impossible in practice. Apart from that difficulty, do you think enough information is preserved in the location of all atoms in a cryopreserved brain, so that given detailed knowledge of how brains work in general this information would in theory be sufficient to reconstruct the initial person (even if this information is impractical to actually extract or process)? One possibility for avoiding the reconstruction of brains out of atoms is to instead reconstruct a Whole Brain Emulation of the original person. Do you think developing the technology of WBE is similarly impossible, or that there are analogous difficulties with use of WBE for this purpose?

Comment author: kalla724 13 May 2012 10:10:28PM 22 points [-]

I don't believe so. Distortion of the membranes and replacement of solvent irretrievably destroys information that I believe to be essential to the structure of the mind. I don't think that would ever be readable into anything but a pale copy of the original person, no matter what kind of technological advance occurs (information simply isn't there to be read, regardless of how advanced the reader may be).