Emergent effects; Pointing demo

[From Bill Powers (940423.1205 MDST)]

Wayne Hershberger (940422.2020) --

and, I'll buy that (i.e., the control is not based on the

   even if they do, the information is travelling away from
   the control system,

But I'll not buy that. What you are calling physical effects
propagate one way around the control loop, but the informing I
am talking about goes the other direction.

Then this "informing" is a metaphorical process, not physically
mediated. I don't mind this usage as long as we both understand that
you're speaking poetically.

I am talking about the direction of the emergent cause-effect
relations found in control systems and not the direction of the
circuit of influence comprising the parts of the loop. These
emergent properties of control systems are counter intuitive--
as you well know.

This emergent effect exists in the interpretations of the beholder,
not in the control system. I introduced it to make a contrast with
another metaphorical or poetic interpretation of behavior, namely
that stimuli cause responses, or still another, that cognitions
direct actions. The truth of the matter (given PCT) is that a
control system represents a set of variables and functions in
dynamic equilibrium, which behave in a way not correctly described
by any of these metaphors. The idea that disturbances cause outputs
while reference signals cause inputs is a summary of _appearances_
put in layman's language. We use this language when speaking broadly
about behavior, particularly with people who we know are not likely
to understand the real analysis of control-system operation.

A matter of considerable interest to me is how a complex
control system such as an animal might not only monitor its own
output, but partition that output into components which
"represent" ( including misrepresent) different parts of the
net disturbance-- e.g., self and envirionment.

As long as you think of the whole organism as a single complex
control system, this is going to be hard to do. In HPCT, we have
many autonomous control systems working at once, side by side and at
different levels. This allows for one system to be concerned with
controlling one variable in an explainable way, while another system
is concerned with some other aspect of the experienced world,
independently of the first system, again controlling in an
understandable way.

As you present the problem -- "... partition that output into
components which 'represent' ( including misrepresent) different
parts of the net disturbance... " -- it can't be solved. A single
variable that has only one value at a time can't be "partitioned" at
all. If the components of a net disturbance are to be distinguished,
they must be individually represented in perception. Given only the
number 23, what are its components? The answer is that there is an
infinity of choices. Some _other_information must be provided.

Consider for instance the "magic swing." A room is suspended
from a horizontal axle which bisects the ceiling. The room
swings to and fro whereas a conventional rope swing, suspended
from the same axle, hangs down like a pedulum bob. If one sits
in the stationary swing, one perceives onself to be swinging.
Why? If one could null all retinal motion by fixating a point
on the wall, would one perceive onself to be stationary and the
room to be moving? Why? Why not?

I presume you're speaking of a real experiment. In the real
experiment, vestibular and bodily inertial information will
immediately inform you that you, not the room, are swinging. If you
are not swinging, you will experience no vestibular sensations and
no sensations caused by centrifugal force. The only valid hypothesis
then would be that the room is swinging. Whether one notices this
information and interprets it appropriately is, of course, the
crucial question.

In situations where there is no inertial information about whether
you or the scenery moves, then as Einstein pointed out there is
literally no way to distinguish between the two possibilities, and
both are equally valid interpretations. This would also be true if
the information were available but was not taken into account in
constructing the perception.

In this experiment, did _every single subject_ mistake the swinging
room for their own swinging? I don't think I would. I might at
first, but then I'd notice that the sensations were wrong.


Richard Thurman (940422.1600)--

By the way -- how would you feel about putting your arm
pointing demo into a VR? It might be an interesting demo at
some VR conferences. The VR community is just now getting
around to thinking about how to create virtual citizens.

Feel free to use it in any way you like. Version 1 is probably all
you need: source code available on request (I think it's in Turbo

I've thought that one way to make gobs of money for PCT would be to
convince the people at Industrial Light and Magic that the way to
create computer monsters and people is to simulate their behavior
instead of animating it. Even Little Man Version 1 behaves more
realistically than animations do. If someone would supply me with
the forward dynamical equations for an animal with a body and four
two-jointed legs, I would like to write the control systems for
walking, creeping, jumping, etc.. I'll bet that the result would be
very much like a real organism. The human eye is awfully good at
seeing the flaws in animations, even when they're traced from life.
But how do I convince IL&M that they should hire me a physicist-
mathematician for six months to develop the dynamical equations?
Would anybody in your outfit be interested?
Best to all,

Bill P.