Uploading the wet stuff

John K Clark (johnkc@well.com)
Mon, 20 Jul 1998 12:48:29 -0700 (PDT)


"Jonathan Colvin" <jcolvin@ican.net> On Mon, 20 Jul 1998 Wrote:


>It [Uploading] seems to rest on a very narrow model of consciousness
>that regards neurons as discrete computational elements that can be

Unless a neuron has a soul it can be simulated. One neuron sees another neuron as a black box, it doesn't matter how it does what it does as long as it gets the job done.

>I think this model seriously de-emphasizes the chemical elements of
>consciousness...the enormously complicated stew of neurochemicals
>the washes thorugh our brains, [ ...] I am of the opinion that much
>of consciousness is dependent on very complicated chemistry. You
>might say I am of the "wet" school of consciousness. And how can
>you upload norepinephrine?

I don't see the slightest reason why norepinephrine or any other neurotransmitter would be especially difficult to simulate, 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 it's 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 minute. 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.

                                              John K Clark    johnkc@well.com

Version: 2.6.i

iQCzAgUBNbOJ4303wfSpid95AQH6ggTuMv9zMKMFs1HkbTJDvR/tO/rxeE1tUIZr 21Y7eX2V6Y9OI8jesobk0SD6xPru/3J0x170sz3OpTNQnjkhf6XZ2VTVVyBXlrUJ HCgfvdDLnO58QBvwl9CQBFxOa8yLJ1qbWhtmNAFRNIAMNPhZd70i0La0/m+CkRjD stgQnoX18gmjNsYoEsqanz3JIH1NhFwSLPngQ9vtM33nAzQKKd0= =7Qmh