SV: Capacity of the brain

Ken Collins KPaulC at email.msn.com
Sun Sep 5 00:01:34 EST 1999


Jan Vorbrueggen <jan at mailhost.neuroinformatik.ruhr-uni-bochum.de> wrote in
message news:y43dwwzaws.fsf at mailhost.neuroinformatik.ruhr-uni-bochum.de...
> Robert Herndon  <rmhj at rmi.net> writes:
>
> > To paraphrase a joke among doctors:  Yes, the brain has about 10^10
neurons.
> > And 10^11 of them are in the cerebellum.
>
> Cortex has about those 10^10 neurons. Cerebellum, for all its neurons,
seems
> a lot more like a specialised piece of hardware doing control of your
limbs.
>
> > I would presume that Vannevar Bush was familiar with the idea that
> > the brain had about 10^10 neurons, and was presuming equivalence
> > between neurons and tubes/gates.  This isn't a fair comparison,
> > however, as neurons often have up to ~1000 connections, and
> > these connections are neither simple, symmetric or equivalent to
> > each other, nor immutably fixed in character.
>
> Quite so. I'd say the three-dimensional character of the wiring and its
> plasticity is what makes otherwise inferior hardware that performant. And
> our estimate of the complexity of a single cortical neuron is still
growing.
>
> On the other hand, cortex runs at less than 100 Hz. The difference in
> operating frequency of about 10^7, currently, can make up for a lot.

Forgive me, please... 'inferior hardware'?

surely, you jest?

or, show me the 'chip' that can recreate itself, and its 'momentary'
topology, all in accord with what a system's other 'chips' are doing (in the
same way), on the fly, and retain the ability to do so for 50-100+ years,
despite an ever-changing input set.

'inferior hardware'?

check the landfills for old computer boards... i once helped in discarding
hundreds at one swoop... a whole network being changed from one architecture
to another.

there is an analogue within brain 'hardware'... the pruning of 'synaptic'
ramifications. but such 'pruning' just optimizes the genetic design of the
generalized processor that is the brain.

forgive me, 'inferior hardware'?

cheers, ken collins





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