[From Bill Powers (951202.2350 MST)]
Bruce Abbott (951201.2105 EST)--
I would suggest that most theorists in EAB would be perfectly
comfortable with the idea of innate, target-directed pecking and
have no problem with the notion that directed pecking includes an
error-correction mechanism that keeps the peck aimed toward the
target through corrective action.
That is only because, having little understanding of mechanisms in
general, they don't realize what is entailed in accepting "an error-
correcting mechanism." The situation you describe is a bit like an
amateur inventor having no problem with accepting the principle of
conservation of energy or the second law of thermodynamics, and then
saying "Now, back to my perpetual-motion machine...".
For an error-correcting mechanism to work it must contain a
specification for some sensed state of affairs; it must be able to
compare the sensed state with a real, physical reference state. The
reference state must be physically embodied and it must be located where
it can be directly compared, through a physical operation, with the
sensed state. This means that the reference state must be specified
inside the system, not in its environment. The environment contains
nothing capable of performing such a comparison.
So, once you have accepted an error-correcting mechanism you have,
whether you realize it or not, accepted that the environment does NOT
determine where the bird will peck, or even if it will peck at all. At
that point you have to stop talking about an "unconditional stimulus,"
because you have just denied that it is the stimulus that directs the
pecking toward itself. The only way you can go on speaking as if there
is an S-R connection is to have missed the point of agreeing that there
is an error-correcting mechanism involved.
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if a peck is required, then the illuminated key (CS) by itself is
not a reliable signal for food; only CS+peck is. CS alone then
will not elicit a classically conditioned peck.
What does "signalling food" have to do with classical conditioning? As I
understood it, you begin with a US -> UR connection, an S-R connection
that links an environmental stimulus to a response that it always
produces. In the present case, the US is (correct me if I'm wrong) the
sight of something that might be edible, and the UR is pecking at the
thing. So before conditioning, the bird simply wanders around pecking at
things that might be edible. These pecks are not aimed anywhere in
particular; that is, any object that appears edible might be pecked at.
The key would not be particularly favored; indeed, according to what you
have said, it is difficult to get the bird to peck at the key to get
operant conditioning started.
The CS, now, is the illumination of the key. As I understand classical
conditioning, the CS by itself would not stimulate any behavior; its
role appears only when it is presented just before the US a sufficient
number of times. So if the CS is presented just before a peck at
something that might be edible, the bird will gradually come to peck at
the edible object when the CS appears, without waiting to see the object
(a neat trick). In order for this edible object to be the key, the CS
must be presented just before the key is pecked. Then the key will be
pecked when the CS appears, without waiting to see the key.
I confess that I'm already completely confused. What exactly are the US,
the CS, the UR, and the CR? And what is the role of the food delivered
when the key is illuminated, with or without a peck?
In Pavlov's experiment, the US was the puff of meat powder into the
mouth, and the UR was salivation which dissolved the dry powder and made
it ingestible. The CS was a bell rung just before the puff of meat
powder. If we use a parallel construction, the US in the autoshaping
experiment ought to be the delivery of food, and the UR the act of
pecking at the food and eating it. The CS should be the combination of
illumination of the key and a peck at the key (the peck being considered
not only an action but a stimulus), since these events immediately
precede the food stimulus. But that doesn't seem to be how you're
interpreting the elements of the experiment.
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It seems to me that the success of autoshaping depends on just one
factor: a bird is much more likely to peck at an illuminated key than at
anything else. This, if anything, is the US-UR pair. Since this
unconditional response by itself would be sufficient to get operant
conditioning going, I don't see why any reference to classical
conditioning has to be made.
-------------------------------------
What happens during the time that the key is
illuminated but before the noncontingent delivery of food occurs?
Nothing is _programmed_ to occur.
But isn't the apparatus programmed so that if a keypeck occurs while the
key is illuminated, the food will immediately be delivered? I asked
Does the food appear immediately upon a keypeck when the key is
illuminated?
And you said Yes. I guess I don't know what you mean by saying that
nothing is programmed to occur. Just to make sure, I asked
is not
the delivery of food contingent on the keypeck just as in operant
conditioning?
And you said Yes.
However, it is possible to program the experiment so that food
delivery would _not_ be contingent on a keypeck; the pigeon need do
nothing but await the delivery of grain at the end of CS
presentation. Here there is no operant procedure in effect (no
immediate reinforcement of the keypeck response), yet what is
observed is that the pigeon begins to peck at the key anyway,
although it is a total waste of the pigeon's effort. But if
keypecking is an innate response sequence released by certain
perceptions (under the right conditions), then the procedure meets
the specification for a classical conditioning procedure.
Is it part of operant or classical conditioning theory to assume that
pigeons do not like to waste their efforts? If that's true, why do we
observe superstitious behavior?
Doesn't all this sound a bit ad-hoc even to you? If keypecking is an
innate response sequence (pretty hard to imagine; pecking, sure, but
KEYpecking?) then why is it so hard to get the pigeon to peck the key in
ordinary operant conditioning? If pecking is released by certain
perceptions under the right conditions, then sure, what happens would
happen. Obviously the perceptions are the right ones and the conditions
are right; you just said they are. But aren't those assumptions being
made out of thin air specifically to explain what happens? Isn't that
what "ad hoc" means? What's this "releasing" business? Is that different
from "causing?" From "triggering?" From "eliciting?" From "setting the
conditions for?"
Bruce, this is a horrible, sloppy, shifty way of constructing an
explanation. Why do I have to ask all these questions? Can't you just
lay out the definitions and the logic of the explanation and show how it
works? Every time I raise a new question, you seem to have a new answer.
I feel like John Cleese being sold a parrot by Michael Palin.
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If you introduce disturbances in an operant conditioning experiment,
you will no longer be able to define a reinforcer, because no state of
the variable in question will increase the probability of any
particular response. In fact, the responses can be made independent of
the state of the reinforcer, yet control will continue.I have repeatedly brought this point up, without a comment from you.
Ah, you cut me to the quick! I have indeed commented: check your
archive. I don't remember which post, but my reply was given the
last time you brought up the topic. As I recall, you asked me
about it in the form of a test. After reading my reply, you said I
passed. Remember?
I didn't ask you about the implications for the reinforcement
explanation. You accept that actions vary as disturbances are applied to
the controlled variable; you definitely passed that question. But if
that's true, and if reinforcers are controlled variables, what does this
imply about the statement that reinforcement increases the probability
of the response that produces the reinforcement? With a varying
independent disturbance acting directly on the controlled variable, the
"responses" of the system will be varying over the whole possible range,
yet the system will continue to produce essentially the same amount of
"reinforcer." When no disturbances are present, as in almost all op-cond
experiments, a false impression is created that a particular response
always goes with a particular reinforcer. So a false generalization is
created: the idea that a particular consequence of a response is what is
bringing the response into being and maintaining it. Applying a
disturbance reveals the general case, and in the general case that
generalization is wrong. In the general case, there is no particular
relationship between reinforcement and a change in the probability of
any particular response. This can be experimentally demonstrated.
I hope you're not going to be like that amateur inventor. Sure, the same
value of the controlled variable can go with completely different
directions and amounts of response. Now back to the maintenance of
responses by their reinforcing consequences ...
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Best,
Bill P.