Statistics, perception

[From Rick Marken (921020.0930)]

Bill Powers (921013.0930) --

It strikes me that one problem with "residuals" and all that is simply
that the wrong model is used (as you say). Is there anything to
prevent you from doing statistical manipulations using a closed-loop
model instead of an open-loop one? In fact, isn't that pretty much
what we do, although informally? We're trying to fit a linear model to
the data to obtain the minimum least-squares error of prediction,
aren't we? The only difference is that our linear model embodies a
closed loop.

Yes. As I said to Martin, I think it would be great if he could show
HOW he would go from observation of the data to modification of the
model. My impression (which Martin has yet to dispel) is that Martin
was suggesting that you COULD improve the control model by analyzing
the data in terms of an open loop model (and Martin's statistical
model IS an open loop model). If Martin had something else in mind,
then I wish he would clear it up for me. As I said, I think it would
be an enormous (and, I think feasible) contribution to PCT if he
could develop an analytic technique for going from discrepencies between
model and actual behavior to revision of the parameters of the closed
loop model to improve the fit.

Wayne Hershberger (921010) --

Perception is NOT simply a process of
transporting a representation of some putative conceptual reality
comprising one end of the dipole (the environmental pole) into the
other end (the organism pole). Such a conceptualization
(representationalism) begs the fundamental question of perception,
which is the realization of the perceptual world in the first

What is your model of perception, Wayne?

Here is my model:

EV --->S--->PF--->PS

where EV is an evironmental variable, S is a sensor, PF is a perceptual
function and PS is a perceptual signal. The EV is known only in terms of
our models of physics. But whatever EVs REALLY are, they impinge on S (based
on our models of physiology) which transforms the EV into neural signals
(the physiological model again) that enter a neural netork that acts as
a computation device (PF) that converts the input neural signals into
an output neural signal, the perceptual signal (PS) -- all this is based
on the physiological model. I imagine that it is PS that IS the experienced
perception (this is the PCT mind model). In your example of "diagonal
movement", PS IS the perception of diagonal movement -- constructed
from the sensory inputs that are ultimately caused by the horizontal
and vertical EV movements. What else is needed here -- other than
the delineation of how PS results from EV -- ie. other than the model
of PF and S? What is your model of perception? How does it work?

Gary Cziko --

Thanks for sending the note to Ari. It was very clear and helpful
as usual.

By the way, I have not heard a peep from Psycholoquy about my Blindmen
paper. Better start thinking about the next place to send it.

Best regards




Richard S. Marken USMail: 10459 Holman Ave
The Aerospace Corporation Los Angeles, CA 90024
(310) 336-6214 (day)
(310) 474-0313 (evening)