NEURO: Advanced Neurons?

John K Clark (
Mon, 17 Mar 1997 23:05:04 -0800 (PST)


On Mon, 17 Mar 1997 Eugene Leitl <> Wrote:

>(Remember Moravec's double bogus argument upon collapsibility of the
>retina, and his grand sweeping extrapolation, judging from retina to
>the cortex, regarding merely the most trivial functions, assuming an
>identical architecture on no empiric grounds whatsoever).

There is nothing trivial about it, the density of neurons in the retina is
100 times greater than any other part of the brain, Moravec used it because
it's the most studied part of the brain. I think it's a quit reasonable thing
to do. Moravec assumed 10 bits per synapse, also quite reasonable at the time
but we now know that's way too high.

>there is a minimal computational work to be done to simulate a given
>physical system realistically.

No doubt.

>minimal threshold may lie quite high for such complex objects as a
>mammal brain.

No need to say "may", you will definitely need to do a hell of a lot of
computations to emulate any mammal's brain, and there is no reason why a very
small object couldn't perform a hell of a lot of computations.

>Human equivalents the size of a sugar cube, running at
>speeds >10^6 of realtime seem to reside firmly in the realm
>of science fiction,

Well of course it's Science Fiction, nobody has done it yet, and 10^9 is
probably closer to the truth.

>not even very good science fiction.

For me good Science Fiction extends current ideas to the absolute limit
without breaking the laws of Physics. I think a sugar cube sized super brain
is very good Science Fiction.

>Darwin doesn't operate on individuals, but on populations.

If the unit of natural selection is the population then what constitutes a
population? Are The Extropians a population? How about a nation, or the
Human Race, or primates or mammals or vertebrates or animals or life in

Darwin doesn't operate on individuals, but on genes, the basic unit of

John K Clark

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