X-Message-Number: 3458
From:  (Thomas Donaldson)
Subject: CRYONICS: RE #3301 by Stodolsky
Date: Sat, 10 Dec 1994 20:11:36 -0800 (PST)


With respect to David Stodolsky's posting (#3301), while I feel wary about 
the notion that it will be so simple to resurrect us in another form, it 
contains a common major error (not due to David):

It is simply not true that Ralph Merkle has shown that we can repair our
brains by loading them into a computer. In his wwritings, he has indeed shown
that computers of the (probable "near" future) will be able to hold the needed
information, but that is only one part of the process. What will be loaded into
such computers is not the state of our whole and healthy brain, but the state
of our brains after (primitive and clumsy) cryopreservation. Unfortunately it
remains unclear that enough information remains after freezing to allow 
restoration of a whole and healthy brain.

(Don't misunderstand me here. I write this as a cryonicist; but it is precisely
because of this problem, the possible destruction of information by current
means of cryopreservation, that I would not want to be suspended unless the
alternative were the CERTAIN destruction of my brain by old-fashioned DEATH).

The main problem comes the possibility of cracks separating neurons from one
another. Since the best current theories of memory say that it is the
synapses (the connections between neurons) which encode our memory in their
relative strengths, if these connections become sufficiently disrupted it
will become a very hard problem to work out the correct ones. Depending on many
features of the brain which we don't yet know about, that hard problem could
be literally impossible or simply one that would take a long long time --- long
enough (say several million years) that for practical purposes it would be

Or again, the problem may be easy. For instance, if nerve connections were
ACTIVELY MAINTAINED then we might be able to tell, say by examining the neural
DNA, just what connections a nerve cell had. Or else the diversity of neuro-
transmitters and receptors for different synapses might be great enough for us
to work out just which connections formerly existed and which did not. 

But these are only possibilities, not certainties. Presently we understand
brains and memory too little to use any features of our brain to infer 
what connections should have been.

Merkle has not PROVEN anything very important. I do believe that massive
computers will someday be used for repair, but those computers require data
to work on. It is quite simply an error to believe that to recover the needed
information we need only read a patient's brain into a large enough computer. 

I will also say that the recent work by the Cryonics Institute shows some very
hopeful results on this problem of cracking: they found none. Furthermore, if
we can vitrify brains rather than freeze them, this cracking problem will also
disappear. I personally would go so far as to say that cracking presently is
THE major problem; once solved, patients suspended by methods which would NOT
cause cracking are very very likely to retain all the information needed ---
whether or not we read them into a computer. Yes, there are other ways in
which suspensions could go wrong, but I think those OTHER ways are more or less
carping at the edges.

That won't finish the problem, of course. It will only finish it for those who
lived long enough to be suspended by better methods. For others, of whom there
may be many (depending on how fast the cryonics community works together to 
solve this problem) we are left with a big question mark.

			Long long life,

		           Thomas Donaldson

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