Anastasio on HPCT

[from Gary Cziko 930505.1925 UTC]

Tom Anastasio is a neurophysiologist at this university studying the
vestibular-ocular reflex (I prefer to call it the retinal image stabilizing
system). His wife works with my wife as healers and we often wind up at
the same social gatherings. So how could I resist talking to him about PCT
and bugging him incessantly to read Powers 1973?

He finally gave in (most smart people would learn to avoid me, but our
respective wives keep dragging us to the same places, so avoidance is
hard). Here is his preliminary report on Powers 1973. I have already
responded to part of Tom's reaction, but I wanted to share it with the net
in the hope that some PCT veterans like Bill Powers, Rick Marken, Tom
Bourbon, Greg Williams and Wayne Hershberger could also respond (Tom has
given me permission to post this).

Tom is not on CSGnet (yet?) and so I will act as the link between the net
and him until he either signs on we chase him away (let's try for the


[from Tom Anastasio <>]


I'm really enjoying Powers' book. I'm into chapter 15 (on memory) so I'm
almost finished. So far, I've found lots of ideas which are central to my
area of research, such as vectorized quantities and integration by closed
loops, in addition to control by negative feedback. These ideas are fairly
well accepted by us and have been and continue to be elaborated and
tested by investigators in our field. I would be extremely impressed (and
quite surprised) if Powers himself is the originator of these ideas as they
have been applied to oculomotor neurophysiology. I would be surprised
because I've never seen a reference to Powers in all the papers I've read in
my field concerned with these topics.

What's new to me is the idea of hierarchical control in the sense of nested
control loops. This has very interesting implications for the organization
of the brain as a whole. In my opinion, HPCT is a very elegant theory. If
I do move on to higher level parts of the brain in my research, HPCT is an
idea I may well fall back on in trying to evaluate my findings.

What I continue to be puzzled by, however, is the apparent persecution
that HPCT adherents seem to suffer. This is brought out in the paper you
sent to which I am responding. Can it be true that scientists who want to
test HPCT are actively restrained from doing so? It cannot be disputed that
science is resistant to change. I think all of us who are subject to peer
review have felt this inertia. I have even spoken out in favor of
reforming the peer review process, to make it more democratic. But good
ideas always manage to generate some support and this allows them to grow.
I've got to beleive that in 40 years, HPCT has generated some scientific
results of real merit. In my opinion, the case for HPCT could be made much
more strongly by citing evidence in its favor. This could invlove the use
of HPCT to explain previously mysterious data, or the results of actual
tests designed to directly test the theory. I'm assuming this data is out
there. My suggestion is to heavily incorporate this into Powers' paper.
Include citations and detailed explanations of how HPCT, more than being an
elegant idea, has led to a deeper understanding of SPECIFIC brain processes.

No one will argue against the idea that a driver uses negative feedback to
steer a car down the road. What will really convince scientists is hard
data, the more neurophysiological the better, that begins to flesh out HPCT.