Insects;VI schedule functions; seeking conflict

[From Bill Powers (960220.2300 MST)]

Shannon Williams (960219.11:30 CST) --

Your assumption that the tracking models I referred to explain only the
behavior of insects is incorrect, unless Rick, Tom, I, and numerous
other people have, unbeknownst to us, been transformed into giant
cockroaches. The model predictions of which I spoke are for data from
human tracking experiments.

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Bruce Abbott (960220.2020 EST) --

RE: VI schedule feedback function(s)

When you measure behavior in VI schedules with a closed loop system, the
closed loop will modify the actual distribution induced by the irregular
schedule to produce a different apparent distribution. If you're just
trying to characterize the feedback function (which I think is the main
point), all you need to do is supply various steady rates of behavior
(variance of zero) and measure the mean rate and distribution of
reinforcement, for each VI schedule. That will give you the true
character of the feedback function itself.

If you set up the rat's behavior open-loop as an independent random
variable with a particular mean and distribution, and run that through
the schedule, you'll get the product of two stochastic variables. This
may be a good way to measure the effective feedback function, assuming
that the rat's variability in rate of pressing is due entirely to
irreducible noise in the rat's output. However, this is a shaky
hypothesis when you are using a variable schedule, because even with a
perfectly regular rat function (with no internal noise), the statistical
variations in the feedback function will lead to random-appearing
variations in the system output. Unless you can show that these same
variations would be present with a perfectly regular rate of
reinforcement, you can't assign them to behavior as if they were an
inherent part of the rat's actions. Nor is the resulting product
representative of the feedback function.

I kept meaning to bring this up way back in the battle over the E. coli
model, and kept forgetting. By generating behavior using a probabilistic
output function (constant probability of a press per unit time, etc.),
you are making a claim not only about observed mean rates, but about
observed variances in the behavior rate. If the actual behavior is not
as variable as the model's behavior, a different means of generating the
behavior has to be found. Your model of E. coli showed much too much
random variation in the measured dependence of tumbling delay on rate of
change of concentration, as measured by Koshland using perfusion of
tethered bacteria. The actual response was quite regular.

What news on prospects for getting the rat experiments started?
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Rick Marken (960220.1500) --
Martin Taylor (960220 16:50) --

RE: intentional conflicts

I think you're both right about people who choose conflict deliberately.
After all, the US is a great example of a culture that adores conflict
not only in sports, but in business and politics, between people and
animals, between animals and animals, and in just about any other form
you could name.

What people seem unaware of is the connection between this love of
conflict and all the side-effects which result from it: poverty, war,
crime, cruelty, injustice, and so forth. While doing the very things
that have these results, people bemoan the fact that somehow wars just
happen, somehow the rich get richer and the poor get poorer, somehow the
economy works in booms and busts, somehow crime just seems to get worse,
somehow children rebel against the values of their parents. It's like a
man hitting himself on the head with a hammer: "I wish you'd do
something about that guy with the hammer," he says.
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Best to all,

Bill P.