[From Wayne Hershberger]
Bill, I am delighted with your argument (Powers, 921220)--relating
perceptual and conceptual EVs. Some of your remarks I found
particularly refreshing; for instance:
All we see is the combination of the natural law and the law
represented by the form of the perceptual function.
And,
The...problem is to find organizations of the input
functions that will yield controllable variables
As for your comment:
Some added thoughts about this were in my head when I woke
up (921221).
I can not help observing that it must have been a long night.
More later, Bill.
Gary Cziko:
The VOR is not perfect; nor is the optokinetic reflex. I think
the gain (eye-velocity/head-velocity) of these two reflexes
combined is only about .9, meaning that during active head
rotation of 50 deg/s, images slip across the retina at 5 deg/s.
David Robinson claims that the VOR involves the control of eye
position as well as eye velocity. He also claims that the
saccadic system CONTROLS EYE POSITION VIA CLOSED LOOP CONTROL, and
argues that this phylogenetically late system commandeered aspects
of the earlier VOR system in its development.
I believe Tom Bourbon's recent post regarding the control of error
is really an essay concerning feedforward. Feedforward can be
thought of as endogenous disturbances to reference signals, error
signals, or output (as I argued in my ABS article in the special
issue edited by Rick). You might want to reread Tom's posts with
that in mind.
Tom Bourbon:
Your post regarding the disturbance of error signals is germane to
the discussion Andy and I were having in Durango about Pavlovian
conditioning. Has he read your post?
Warm regards, Wayne
Wayne A. Hershberger Work: (815) 753-7097
Professor of Psychology
Department of Psychology Home: (815) 758-3747
Northern Illinois University
DeKalb IL 60115 Bitnet: tj0wah1@niu