Technology as Loop Gain

[from Gary Cziko 920602.1500]

Rick Marken (920531) said:

So it seems that higher level systems can serve to increase
the loop gain of lower level systems without necessarily changing
the physical construction of the control system itself. This
might be a way of looking at the evolutionary advantage of having
higher level control systems; its a way to increase loop gain
without too much structural change in the organism. That is,
higher level systems let you increase K by increasing k.f rather
than k.o.

This post got me thinking about technological evolution and how it fits
into control theory thinking.

The development of technology might usefully be seen as ways of increasing
loop gain in the person-environment loop. Rick mentioned increasing the
environment feedback factor k.f. The most obvious examples of this are
machines that allow us to achieve very large environmental effects with
little output--an individual can dig a trench with a back hoe by just
twiddling some levers and pedals for an hour instead of breaking his back
with a pick and shovel for a week.

But there is also the perceptual side as well. We increase perceptual gain
by using instruments like microscopes, cloud chambers and Hubble

Put the two together and you get a tremendous increase in environmental
control because of the high total loop gain. And you don't need much k.o
at all. Indeed, k.o (muscular strength) probably tends to drop as
technology drives up k.f and k.i.--Gary


Gary A. Cziko Telephone: (217) 333-4382
Educational Psychology FAX: (217) 244-0538
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