[From Bruce Abbott (950605.1210 EST)]
Rick Marken (950604.1450)]
Bruce Abbott (950604.1510 EST) --
When the rats entered the condition in which they could not control
the shock, the lever they had used for this purpose in the controllable-
shock condition was retracted into the chamber wall.
Then the study is quite different than the one I mentioned from "Mind
Readings" (though you should read the book anyway). Apparently, the
rats in your study had a choice between working to keep the shock rate
at some level versus not working to keep the shock rate at the same
level. I'm not surprised that they were indifferent to the two
situations. Indeed, I would have expected a preference for the second
(no control) condition.
In the absence of other information, yes, so would I. But what if just
HAVING control is itself a controlled perception? Maintaining that
perception might have been "worth" a little extra effort. My study was
designed to find out.
So why did I think rats might _prefer_ having control? Earlier research had
shown that, in rats at least, shock that was controllable was less aversive
and had milder physiological effects than otherwise equivalent shock that
was uncontrollable. Given this, a logical inference would be that rats
given the choice between controllable and uncontrollable shock would prefer
the former. My study showed quite conclusively that they don't, at least
under the conditions I tested. There remains, of course, the possibility
that they might prefer control under other circumstances.
Why do you think the rats were indifferent? As I said above, one might
actually expect them to prefer the "no control" situation. The rat is
getting the same perception (number and distribution of shocks) in two
situations; in one situation the rat has to work to get this perception, in
the other it doesn't.
I suspect that any preference that might have existed for the "no control"
situation was weak and fell below the limits of experimental error.
There is an apparently common-sensical idea that people who are experiencing
stress in their lives should be given more control over the sorts of things
that cause the stress, and that this control (even if illusory) will
diminish the impact of those events. My research (and a little thought)
suggests that this idea is not necessarily true. Having the perception of
control will probably reduce the stressfulness of the situation if your
experience suggests that this control will generally lead to an objectively
better outcome than if you lacked control. For example, you may feel more
relaxed when YOU drive the car than when your teenage son, who has had two
weeks of driving experience, is behind the wheel. However, having the
perception of control will probably _increase_ the stressfulness of the
situation if your experience suggests that this control will generally lead
to an objectively _worse_ outcome. For example, you might feel much more
comfortable allowing the pilot to land the 737 you are flying in than taking
the wheel yourself. In my study the rats were able to compare the objective
outcome under controllable- and uncontrollable-shock conditions and
determine that they were the same. Given that determination, there was no
basis for choosing one condition over the other and the rats remained
indifferent (within the limits of experimental sensitivity).
If the "reinforcer" is having the picture in focus, and the picture is
already in focus, then the response does not _produce_ the reinforcer
and thus should not be maintained. Rather than being "disabused of
this notion" by the results of your suggested demonstration,
reinforcement theorists would have found support in them.
I think you're right. I've found it impossible to disabuse a
reinforcement theorist of the notion that reinforcement strengthens
behavior. Demonstrations (like E. coli) don't work; modelling doesn't
work.
Do you think there is any way to convince a reinforcement theorist
that there is no such thing as reinforcement?
Yes, but I think it's going to take a whole series of demonstrations to
drive the point home. I've already driven the stake through the heart of
more than one theoretical vampire only to find, much to my surprise, that I
hadn't killed it after all, so I'm not surprised that you've had the same
result. Winning this argument is going to be more like piling blocks on the
lighter of the pan balance until it finally tips. The other guys are
keeping their hands pressed firmly down on the other pan, and you're going
to have to overcome that force and not just the weight of the theory itself.
One difficulty is that there _is_ such a thing as reinforcement--by
definition. So when you tell a reinforcement theorist that there "ain't no
such thing," you're bound to be met with a bit of skepticism. I'll try to
clarify this point with an example. Let's say you meet some people who
believe that lightning bolts are weapons thrown by Thor, the god of thunder.
You try to explain that their belief is wrong, because there are no such
things as thunder bolts. Thor's followers might be forgiven for dismissing
you out of hand--after all, lightning bolts are empirical facts! Of course,
what you MEAN is that lightning bolts, DEFINED AS WEAPONS THROWN BY THOR, do
not exist, but that subtle distinction gets missed.
If I food-deprive a rat for a few hours and then give the rat the
opportunity to earn a bit of food by pressing a lever, the rat learns to
press the lever. The frequency of lever-pressing will increase over time
and will be maintained at some higher level so long as the rat remains
hungry and the contingency between lever-pressing and pellet delivery
remains in effect. The observed increase in responding is _by definition_
reinforcement. Thus the argument is not whether there is or is not a
phenomenon which has been labeled "reinforcement," but how this phenomenon
is to be explained.
Reinforcement theory holds that certain sensory consequences of responding
cause changes to occur in the nervous system that make it more likely that
the response will occur again. PCT holds that responding increases because
error between a controlled perception and its reference level generates
output that tends to reduce the error; given the environmental feedback
function, reduction of error requires an increase in (lever-pressing)
output. Reinforcement theory makes reinforcement the central explanatory
principle for behavior change; PCT makes it a side-effect of control. The
argument is not about the objective phenomenon of reinforcement but its
theoretical significance.
Regards,
Bruce