Jesse Mazer wrote:
[quoting Stathis, responding to a post by George Levy]
The "high standard" I have described does not go nearly as far as copying
the exact quantum state of every atom. It is merely aknowledging the fact
that information in brains is not stored in the anatomical arrangement of
neurons, any more than data on a computer is stored in the computer's
circuit diagram.
If you scan the anatomical arrangement of synapses *and* the concentration
of all the relevant proteins at the synapses, you probably would have
enough to run a simulation that would act like a continuation of the
original person. The upload might find he'd lost his short-term memories of
what happened immediately before he died and his brain was frozen (just as
we often do when we regain consciousness after being suddenly knocked
unconscious by an accident), but as I understand it long-term memories are
stored in terms of the pattern of synaptic connections and the
neurotransmitters at each synapse, and as long as the simulated neurons
behave closely enough to how the original neurons behaved, shouldn't the
upload behave like the original person in terms of personality, thought
processes, emotions, preferences and so forth?
I have no problem with the idea that everything about a person's
personality, memories etc. is physically encoded in his brain, and that in
principle, sufficiently detailed knowledge about his brain should allow an
emulation on a computer which would be just like the original person. The
problems are:
(1) what is the level of detail of neuronal information required;
(2) can this requisite information be preserved in a post-mortem specimen;
(3) can the information be scanned or read in a way that can be used in a
computer model;
(4) can each subsystem of neuronal function relevant to cognition be
modelled closely enough to allow emulation;
(5) given adequate information and adequate models, is the computer power
available up to the task of emulation in anything like real time?
I believe the level of detail required and the complexity of the required
models is grossly underestimated. Simply getting a 3D image of a brain down
to electron microscopic detail, including all the synaptic connections,
would be an enormous task, and it probabaly wouldn't tell us any more about
the mind of the brain's owner than a picture of the books on a library shelf
would tell us about the book contents. I would bet more on mediaeval monks
decoding the data on a DVD sent back in time than I would bet on scientists
decoding the contents of a human mind from cryopreserved brain sections.
If mind uploads were to become a reality, I think the best strategy would be
research into brain-computer interfacing.
--Stathis Papaioannou
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