Voluntary vs emotional control

[From Bruce Abbott (961016.1250 EST)]

Bill Powers (961016.0800 MDT) --


Did you know that the pattern of facial muscle-contraction that appears
under emotional control (e.g., smiling when happy) differs from that which
is produced when you try to simulate the expression? Did you know that
certain brain lesions will abolish the latter (voluntary control over the
facial muscles) but leave the emotional control untouched and functional?
If this is true (and I haven't seen the support for it yet), this would seem
very difficult to reconcile with HPCT, but fits perfectly with my >suggestion.

Speaking of this observation, I note that Bill Powers has been rather mute
about it. Perhaps he will yet grant us the favor of a comment.


I was sort of hoping to hear an HPCT explanation of it from you. It's not
hard to come up with, although like any guess it's hypothetical. Remember
that this is a _hierarchical_ model, with many levels above the level of
facial configuration control, and many systems at each level (as many as you
need). In my emotion model, there must be some level where the downgoing
reference signals branch into the behavioral and the somatic branches (or
perhaps this happens at several lower levels). "Voluntary" control is
generally associated with higher systems, although all control is in one
sense voluntary. With that kit of parts, can't you put together a plausible
explanation for the effects of "certain brain lesions" by postulating which
paths in the model they interrupt and which they leave intact?

The hierarchical model suggests that the opposite is also possible; that a
lesion could abolish "emotional" control of somatic concomitants of facial
expression while leaving "voluntary" (high-level) control intact. It also
suggests that both could be abolished (deadpan expression syndrome).

Certainly both possibilities are inherent in the model I propose -- there
are dual systems through which high-level perceptual elements can command
(set references of) lower-level motor systems; selectively knock one out and
the other remains functional. (This is no surprise as the model was
developed partly to handle data such as these.) As to the HPCT model, it
seems to me that interrupting the neural pathway linking the output of one
level to the references of the next should produce (at best) a fixed
reference for the latter system, so that it becomes capable of responding
only to disturbances of its CV. The only alternative is to assume multiple
inputs from different control systems operating at the same level in the
hierarchy and controlling different variables, and that the interruption has
affected only those inputs which we experience as under conscious
("voluntary") control, so I will assume that this is what you have in mind.

One could imagine a high-level system whose output sets references for, say,
two sets of next-level-under control systems, both of which set the same
references for facial muscle contractile patterns, I suppose. This leads to
a NASA-like redundancy in which cutting the fibers leading along one path
leaves control intact via the other path. However, it seems to me that such
a case leads you to adopt exactly my position, for the two alternate
pathways through which control over facial muscle tensions is orchestrated
correlate experientially with different perceptions of control, which we
label "voluntary" and "involuntary" and which I would identify with the
cognitive and emotional systems, respectively. The latter produces a
distinct, recognizable pattern of contractions (reference settings) that is
automatic, unconscious, and at least during early development, unlearned.
The former can produce a semblance of that pattern (the "fake" smile,
although some learn to make a convincing show of it) by assembling an
appropriate pattern of reference levels. If we're going to have at least
two parallel sources of control merging onto the same final common pathways,
my proposal at least recognizes that fact explicitly and also explains why
the basic facial patterns displayed involuntarily under different emotional
states are present even in blind infants, who certainly could not have
learned them by observation.

You're assuming that certain signals with certain meanings get into the
emotion control system because you need them to be there and to be
recognized, in order to make the emotion control system work as you want it
to. But why do you want it to work that way? Are you working out of some
principle that says that emotions HAVE to have a separate origin and
separate control over behavior? It's clearly too early in the development of
your model for that arrangement to come as a conclusion to your reasoning;
it's already being accepted as the goal which the model has to attain, or as
a premise which is taken for granted. Is there some underlying reason for
preferring this model, regardless of the difficulties in working it out?

Emotion control system_s_. And even that is misleading (could be
interpreted as control of emotions, which is not my intention), I _mean_
innately-organized control systems whose actions give rise to the
perceptions we interpret as manifestations of emotion.

The reason I want to specify such systems, which receive "just the right
signals" (doesn't every control system?) required to control their CVs, is
that there is, in my judgment, overwhelming evidence for their existence
independent of what we are calling the "voluntary" control systems (and I
admit that the term "voluntary" can be problematic in some cases, but I
think the distinction will do for the present discussion). [I also believe
that these emotion systems both influence and are influenced by the
cognitive perceptual elements of the brain (e.g., biasing the perceptual
systems and acting on references at high levels in the "voluntary" systems),
although I have yet to flesh out that aspect in any detail.] Unfortunately,
the system I am beginning to envision (dimly) is complex, partly redundant,
and from an analytic point of view, messy. Biological systems, being the
products of undirected evolution, are not constructed the way an engineer
might design such a system, beginning with a fresh sheet of paper, and we
who wish to understand how such systems operate must cope with the systems
as we find them, not as our best logical thinking and esthetic sense would
suggest they should be.