[From Bruce Abbott (990404.1935 EST)]
Bill Powers (990404.1334 MDT) --
Bruce Abbott (990404.1335 EST)
I wrote a long reply and trashed it. Arguing with you about these
experiments is just as pointless now as it was the first time I gave up
doing it. The experiments you describe are so poorly conceived, the data
taken so badly analyzed, and your conclusions derived by such mysterious
processes, that I despair of explaining to you what is wrong with them. If
you could understand any explanation I would give, you wouldn't have done
the experiments that way in the first place, or admired whoever did them.
Ah, yes. Now the experiments are "poorly conceived," the data "badly
analyzed," the conclusions derived by "mysterious processes." A flurry of
unsupported assertions designed to pooh-pooh the results and the conclusions
I derive from them. Furthermore, I am now judged to be too stupid to
understand your explanations. Well, be that as it may, how about rendering
the explanation just for the benefit of any (if such exist) who may have the
intellectual horsepower to follow you. After all, I've taken the trouble to
lay out a coherent position, and all you have to do is explain why, from
your perspective, it falls short. Shouldn't be all that difficult.
I'll just give one example, the problem of measuring "rate of lever
pressing," a measure of a repetitive behavior. I thought you had understood
my original critique of the practice of using session averages for this
measure: total presses per session divided by session duration. If pressing
behavior were one simple kind of behavior that simply speeded up and slowed
down, a session average might (at a stretch) be a useful measure. But when
the animal's behavior changes _qualitatively_ during a session, so it
spends time away from the lever engaged in other activities, session
averages become completely invalid, giving true measures neither of
lever-pressing rates nor of any other actions that occur in the same session.
Apparently you are only on "send." I've already indicated that these
within-session changes do not occur on the schedule in question.
Nevertheless, you bring them up as an "example," as if they actually had
anything to do with the results I reported. Magnificent!
Now I do the same thing with another pendulum, but this time I notice, just
after the 50th swing, that the pendulum is squeaking. So I stop it, go get
an oil-can, oil it, go put the oil-can away, return to the pendulum, and
start it up again, resuming the swing count at 51. Then, after the 100th
swing I read the timer as before and compute the period in seconds per swing.
Do you understand why the measure of the second pendulum's period is
invalid? And if that measure is invalid how can it be valid to use a
session average to measure bar-pressing rate when the rat spends part of
the session sleeping?
How about if the pendulum's stopping is not an artifact imposed from outside
its system but a characteristic of its overall, unimpeded behavior? What if
it's one of those fancy "chaotic" pendulums that shows no regular period but
does manifest a long-term quasi-stability in the sense of giving evidence of
a strange attractor? The average period, taken over a run of sufficient
length, might be reasonably stable under given conditions, and change in a
regular way with changes in conditions. Perhaps this would provide a closer
analogy, as the tendency for the rat to do things other than lever-press
varies systematically with such parameters as the average schedule interval.
Do you understand why the measure of this pendulum's period is NOT invalid
as one measure of such a pendulum's performance?
Of course, the notion that the rat is sleeping during part of the session
assumes facts not in evidence. The rat does not spend time sleeping on VI
schedules. You are still confusing the VI results with those on CRF, where
the rat rapidly fills up on pellets and loses interest in earning them.
I thought we had reached agreement about this. But today, your post
indicates that you don't see why a session average doesn't give a true
measure of repetition rate. You haven't budged a millimeter.
It isn't that I haven't "budged." It's that the problem to which you refer
is not relevant to the data at hand.
Let's just drop the whole thing, Bruce. There are too many more problems
just like this, and you won't admit that any of them is a problem. Color me
fed up.
Or in other words, when you can't stand the heat, you get out of the kitchen.
Bill, your whole reply is nothing but a cheap cop-out. I wager that you
have no really convincing rational argument to make. These vague
hand-wavings are nothing but an obvious attempt to dismiss the observations,
and the conclusions based on them, without having to actually present any
argument. I call your bluff.
Regards,
Bruce