From: Lee Corbin (lcorbin@tsoft.com)
Date: Tue Oct 08 2002 - 18:27:21 MDT
gts writes
> > I'll wager that a lot of people besides Rafal
> > and me find [your axiom] problematic, and
> > you should be interested (if I'm right) in why.
>
> I think a lot of people would consider it simple common
> sense. People do not do things for no reason, which is
> to say that every behavior has a motivation.
But, alas, we have argued at length about what such
a statement *means*. People often have no idea why
they do something. Also, even *if* one concedes that
every behavior has a motivation [sic], then there is
still the sticky problem of *whose* motivation it is.
We've been all through that.
Your notions/speculations about addiction are very
well taken.
> > Now I would most pressingly like to know if such increased
> > activity is seen when an organism merely avoids unpleasant
> > stimuli. For example, a pigeon is conditioned to walk back
> > and forth between two compartments to obtain enough to eat,
> > and this behavior settles into a long term routine. We
> > monitor the activity in the nucleus accumbens and the levels
> > of drugs in its brain. Presumably when first discovering that
> > he can obtain more food by checking out both rooms at the
> > end of the corridor, the novelty of the discovery raises
> > levels. So I am speaking of months later when a "normal"
> > level of all this has been reached.
>
> > We now cause the right 25% of the corridor to be electrically
> > charged so that when the pigeon wanders towards the right side
> > on his path, he receives a painful shock. The pigeon learns to
> > keep towards the left. Does this motivation to avoid the pain
> > result in increased activity in the nucleus accumbens, or in
> > increased drug levels? If it does, then your theory is
> > bolstered (though not, perhaps, disproved if that's not the
> > case).
>
> Any behavior that serves to avoid expected pain can also be seen as a
> behavior that serves to increase expected pleasure. The expectation of
> increased pleasure is certainly an expectation of reward, and thus
> should activate the same circuitry.
But my guess is that the pigeon would just gradually keep
to the left part of the corridor. We cannot say simply
"in order to avoid pain" (in this discussion) because of
the possible implications of consciousness (which you wisely
point out became problematical when discussing alligators),
nor can we simply say anything else without being *very*
careful.
My guess is that as the pigeon gradually began to avoid the
electrical shocks one would *not* see any particular rise
in nucleus accumbens activity, *nor* any enhanced dopamine
levels. One would simply see less neurological activity
that was linked to pain or painful stimuli.
Lee
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