From: John K Clark (johnkclark@fastmail.fm)
Date: Mon Nov 30 2009 - 15:05:37 MST
On Mon, 30 Nov 2009 15:49:40 -0500, "Luke" <wlgriffiths@gmail.com> said:
> If hormones have a "very small informational content" then so do motor
> neuron impulses coming from the brain.
I see nothing sacred in hormones, I don't see the slightest reason why
they or any neurotransmitter would be especially difficult to simulate
through computation, because chemical
messengers are not a sign of sophisticated design on nature's part,
rather it's an example of Evolution's bungling. If you need to inhibit a
nearby neuron there are better ways of sending that signal then
launching a GABA molecule like a message in a bottle thrown into the sea
and waiting ages for it to diffuse to its random target.
I'm not interested in chemicals only the information they contain, I
want the information to get transmitted from cell to cell by best method
and few would send smoke signals if they had a fiber optic cable. The
information content in each molecular message must be tiny, just a few
bits because only about 60 neurotransmitters such as acetylcholine,
norepinephrine and GABA are known, even if the true number is 100 times
greater (or a million times for that matter) the information content of
each signal must be tiny. Also, for the long range stuff, exactly
which neuron receives the signal can not be specified because it relies
on a random process, diffusion. The fact that it's slow as molasses in
February does not add to its charm.
If your job is delivering packages and all the packages are very small
and your boss doesn't care who you give them to as long as it's on the
correct continent and you have until the next ice age to get the work
done, then you don't have a very difficult profession. I see no reason
why simulating that anachronism would present the slightest difficulty.
Artificial neurons could be made to release neurotransmitters as
inefficiently
as natural ones if anybody really wanted to, but it would be pointless
when
there are much faster ways.
Electronics is inherently fast because its electrical signals are sent
by fast light electrons. The brain also uses some electrical signals,
but it doesn't use electrons, it uses ions to send signals, the most
important are chlorine and potassium. A chlorine ion is 65 thousand
times as heavy as an electron, a potassium ion is even heavier, if you
want to talk about gap junctions, the ions they use are millions of
times more massive than
electrons. There is no way to get around it, according to the
fundamental laws of physics, something that has a large mass will be
slow,
very, very, slow.
The great strength biology has over present day electronics is in the
ability of one neuron to make thousands of connections of various
strengths with other neurons. However, I see absolutely nothing in the
fundamental laws of physics that prevents nano machines from doing the
same thing, or better and MUCH faster.
> What's your opinion on "gut feelings"?
It's a subroutine that makes use of Stochastic and Heuristic ideas, at
least that's my gut feeling.
John K Clark
-- John K Clark johnkclark@fastmail.fm -- http://www.fastmail.fm - One of many happy users: http://www.fastmail.fm/docs/quotes.html
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