Re: "analog computer" = useless hypothesis?

From: Anders Sandberg (asa@nada.kth.se)
Date: Sun Apr 01 2001 - 16:02:04 MDT


"J. R. Molloy" <jr@shasta.com> writes:

> From: "Anders Sandberg" <asa@nada.kth.se>
> > There is currently a big debate among us neuroscience people about
> > rate coding vs. spike coding. Neurons in mammals usually send signals
> > by action potentials, quick voltage spikes that cause synapses to
> > transmit the signal to the recipient neurons. This is highly digital
> > in itself, although various nonlinearities in the system make it
> > possible that the interval between spikes might matter for some
> > processes.
>
> Then time may act as an analog influence on human (mammalian) cognition?

Well, remember that timing of neural processes is limited by the speed
of neural interactions (roughly ~1 millisecond). It is doubtful that
precision greater than that is possible without employing many neurons
doing clever things.
 
> It sounds to me like the brain forms its operating modus from
> utility/opportunity rather than from prescription. IOW, whatever
> gets the job done, works well enough.

Exactly. Very useful for creating living beings, but the result is a
mess if you are trying to figure it out. We are looking for general
principles, but evolution has nothing against contingency.
 
> These analog components sound like they're related to senses, yes?

As far as I know, yes. But that could be experimental bias - it is
easy to measure the flow of sensory information.

> Does the sense of time (that humans experience subjectively)
> constitute an analog function?

Not necessarily. Some people make a lot of brain rhythms, especially
claiming theta, gamma or 40 Hz oscilliations correspond to "moments"
in subjective time. I'm not entirely convinced about that.

-- 
-----------------------------------------------------------------------
Anders Sandberg                                      Towards Ascension!
asa@nada.kth.se                            http://www.nada.kth.se/~asa/
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