[From Bill Powers (2003.05.30.0637 MDT)]
David Goldstein
(2003.06.30 EDT)
I
know that I am a Johnny-come-lately to the discussion. However, I think
that Bruce is bringing up some interesting issues. What is the role of
emotion when it comes to the question of what we pay attention
to?
The way I have it worked out, emotion is what we experience after an
error signal has led to preparing the somatic system for action. It might
enter shortly after you have looked up to see the car ahead only two car
lengths away and approaching at an accelerating rate, and are in the
process of jamming the brake through the floor. You may not actually feel
any emotion until well after you’ve saved yourself from a wreck.
Do you agree on this sequence, or do you, too, claim that the amygdala
can sense the visual image of the car ahead, interpret it correctly, and
respond to it by sending signals to the muscles that extend the leg
against the brake? Do you claim that the emotion arises directly from the
image of the car ahead and is the cause of the amygdala’s response? If
so, join the ranks of those who accuse me of arm-waving, while madly
flailing their own around.
I would agree that attention seems drawn to, or seeks out, systems in
which unusually large error exists. Also, reeorganization seems to be
focused where attention is. Causality is not clear in all this.
Bill,
you mention that you notice that your muscles become tense when the
traffic is heavy.
I proposed that they may become tense as a way of increasing loop gain,
since the stiffness of active muscle is greater than that of flaccid
muscle (the force-stretch curve is in fact exponential). I definitely
don’t think that heavy traffic causes my muscles to become tense.
Higher-level control systems do.
Isn
t this because you are afraid that the chances of an accident are higher
and that you don t want to be in an accident with all that
implies?
I doubt that cognitive reasoning comes into it except on a very slow time
scale prior to any emergencies and after the fact as we attempt to
explain our behavior when the emergency is over. I would guess that when
errors start to get larger as traffic density increases , higher systems
experience somewhat greater errors and raise the gain (perhaps by using
the amygdala if it is connected in a way that makes that feasible) to
limit the errors (proximity errors, in traffic). There are other ways of
increasing loop gain which are probably also used (see above). The gain
increase could simply be a consequence of an increased error signal
entering a nonlinear output function.
Might
not this be a case where the Observer enters the
picture?
I think the Observer is always in the picture except perhaps when you’re
unconscious. It’s not clear to me that the Observer and attention are
necessarily the same thing, especially when attention is measured by such
things as direction of gaze. Sitting in a movie with your girlfriend,
your eyes are on the screen but your attention may well be on the
girl.
Yes,
I want to get to the meeting on time. Yes, I want to advance my career.
But my life is more important
than all of that.
No conflict, I put my foot on
the brake.
I will be late, but I live to
fight another day.
By that time, your front bumper is embedded in the trunk of the car
ahead. I think all these considerations are better conceived of as
simultaneous control processes, not a series of steps in after-the-fact
verbal reasoning. You are proceeding toward the meeting, or work. You are
furthering your career. You are making a living. You are avoiding
dangers. These are all perceptual consequences of whatever varying mix of
actions you’re carrying out at the moment. Error signals of some size
exist in all these systems at the same time, and contribute to the
settings of reference signals at the next lower order, whatever that may
be for the system in question.
One of the lower systems, it stands to reason, is concerned with
collision avoidance. The reference level for minimum acceptable distance
may be set by a higher system, and may vary with traffic density (but
because of the resulting proximity errors, not because of the traffic
density “stimulus”). Given the reference setting, the actions
involved in collision avoidance depend only on the error in the system
controlling perceived distance. If the distance is too small, the
collision avoidance system will start applying the brakes, with a speed
depending on the amount of error. This will not cause any appreciable
change in the error signal at the level of “get to the meeting on
time,” because the higher variable (say, estimated time of arrival)
will not change much, percentagewise, on a time scale of a few seconds.
The speed at which you’re driving is already a compromise among several
different control systems. Neither a few seconds of braking or a few
seconds of accelerating will change it much on the time scale, and the
perceptual scale, of the higher system. So an episode of sudden braking
to avoid a collision will be followed by an acceleration back to an
acceptable speed, and perhaps by a higher-order decision to terminate the
cell-phone conversation to keep your gaze on the road and your free hand
on the steering wheel instead of gesturing to emphasize a point. This
episode will have only a minor effect on the perceived time of arrival,
and will be finished much too quickly for the ETA system to affect it
while it’s in progress.
That’s my story, and I maintain that it hangs together better, and
involves a whole lot LESS arm-waving, than the other story, though I will
admit to extending a hand once in a while – just to steady myself, you
understand.
You’re a clinical psychologist: see if you can guess what else I might be
restraining myself from saying.
Best,
Bill P.