Varieties of PCT

[Martin Taylor 2018.05.18.12.46]

Much, but not all, of the problem of long unresolved threads on

CSGnet comes from misunderstandings about the intentions of the
writers when using certain words and phrases. Other problems arise
because each of us, novice or self-appointed expert, has a personal
perception of what is and what is not “PCT”, and of what
consequences arise from that personal perception when it is applied
to the real world. I doubt that any taxonomy could incorporate all
the varieties that different CSGnet readers think of when they think
“PCT”, but it is possible to describe some variations that deserve
the name.

A long time ago, in a mailing list far away, we had three

classifications for variants of PCT. I forget the names we used, but
in principle they were: Generic PCT, Generic Hierarchic PCT, and
Bill Powers’s specific version of Hierarchic PCT (HPCT). Some
contributors to CSGnet now write assuming that Bill’s HPCT was
“PCT”, as though the road to enlightenment was only through studying
Bill’s writings, despite the unavoidable self-contradictions that
occur between his early and late writings. As should be the case for
any good scientist, Bill’s understanding of PCT developed, over the
half-century and more that he studied the control of perception. To
base discussions of PCT only on fine interpretations of Bill’s
writings, especially the earlier ones, is a sure way to create
disputes. Just as an exhaustive study of any ancient writings by
several people will do, the various Koranic, Biblical, or Talmudic
scholars come to different conclusions about the truth that is
hiding behind the Holy Writ of PCT.

My own preference is to work from the other end, to consider Nature,

using my own interpretation of Bill’s powerful insights as a
valuable but not infallible guide. I ask questions such as:
Supposing this or that variant form of PCT happened to be correct,
what would we observe? What limitations does Nature impose on
control, and is this or that version of PCT consistent with those
limits? How could we know whether what we perceive has a counterpart
in properties of the environment in which we live? Etc., etc… One
class of questions concerns whether observed effects depend on
Generic PCT, Generic hierarchic PCT, HPCT, or some other variant, of
which there may be many.

What did we mean by these three levels so long ago? Generic PCT

simply means a theory that organisms create internal variables that
correspond to some patterns of sensory data based on things and
events in the real environment, and act to influence those patterns
to conform to internal “reference variables”. Generic PCT specifies
nothing about the form of these control loops or how one relates to
another. They might all work independently, they might have all
sorts of cross influences or network structures of interaction.
Generic PCT allows almost anything that involves control of internal
variables by action on the environment outside the organism.

Generic Hierarchic PCT (GHPCT) is a specific refinement of Generic

PCT, one of many possible structures of interaction among control
loops. The specific refinement is that the internal (perceptual)
variables individually represent identifiable entities or structures
in the environment. Those that are controlled come in simple and
more complex forms, the more complex being built on the simpler to
form a kind of “tower of complexity” with very complex perceptual
forms at the top and raw sensory data at the base. GHPCT allows any
kind of relationship among the functional processes that lead to
control of these perceptions.

Powers's Hierarchic PCT (HPCT) is a specific refinement of GHPCT, in

which different levels of complexity and a specific form of
interconnections among the functional processes is defined. Although
Powers did not insist on it (at least at the lowest levels), one
might include as a necessary component of HPCT the eleven types of
increasingly complex perception Powers proposed. Of course, I am not
saying that Powers developed his version of PCT by refining GHPCT.
Far from it. The reverse, a generalization from Powers’s HPCT to
GHPCT, would be nearer the truth.

Another way one might categorize varieties of PCT is according to

how the PCT structures evolve over generations and within
individuals. Among other possibilities, we might include e-coli
reorganization, reinforcement learning, Hebbian cell-assembly and
random connection making and breaking, all globally, in modules, or
in hybrid form. Powers’s HPCT incorporates e-coli reorganization
generically, but not in any formal and specific way. Different
variants of Powers’s HPCT would depend on different understandings
of how reorganization functions to change the control hierarchy.

Already we have listed over a dozen possible varieties of PCT, and

these are far from exhaustive. For example, there are other species
of GHPCT, and forms of Generic PCT that are highly structured but
not hierarchic. I don’t know whether anyone has seriously proposed
the following as a PCT variety, but in the silico-acoustic world the
inverse Fourier transform of the log Fourier transform is a useful
tool. Imagine a model in which the controlled perceptions were
quasi-spectral relationships among vectors of logarithmic values.
Structurally, this kind of thing was proposed (a long time ago) for
the distributed character of perceptions to protect them against
focal brain damage, and maybe control of spectral representations
might be functional. Many years ago, when I visited the Swedish
Defence Research Institute I was shown how re-inverting the phase
spectrum of a spatial Fourier transform after losing the amplitude
information produced a good outline drawing of the original
picture. Neural systems seem well suited to doing this kind of
thing, but is it well suited to control in a dynamic environment?
One could actually consider the plethora of specific perceptual
functions of Powers’s HPCT at a given level of the hierarchy as a
kind of quasi-spectral transform, mathematically.

One specific variant of GHPCT that I do like is based on the

apparently different functional tendencies of the brain hemispheres.
This variant is like Powers’s HPCT except that there is no category
level as such. Instead, each of the other perceptual types may
interface with a category process that produces category values and
performs logical operations on them ( (left-brain function))
interacting with analogue values (right-brain function) at each
level. Again, there are probably many variations on this theme, all
producing different variant forms of PCT.

My main point is not to advocate for any changes to Powers's version

of HPCT, but to show how easily variant forms can be imagined. This
being the case, how many more subtly different varieties of PCT may
exist in the hidden assumptions each of us has when we discuss “PCT”
on CSGnet and get into unnecessary arguments. In most cases, so long
as the assumptions remain hidden, arguments are unresolvable about
what is or is not PCT and about what is or is not true of Nature
viewed through a PCT lens. Even if by some lucky chance the
conflicting assumptions are revealed, it is as like as not that no
experiment has been done that could distinguish between them, and
the only rationale for choosing one over the other would be Ockham’s
Razor – and that particular razor shaves differently for different
people (see for
the explanation).
My second point is simply to try to shake up a bit the idea that
some people seem to hold, that “PCT” means exclusively the
constellation of concepts about which Powers wrote. That happens to
be the version of PCT that is by far the most studied and tested,
but it is far from the only one that is possible, and many of the
others would automatically have provided identical results to any
tests that have as yet been applied to the Powers version, including
all studies such as the Test for the Controlled Variable, which
examine only a single isolated control loop.
Martin
“”

···

http://www.mmtaylor.net/Academic/ockham.html

  •  A good scientist always tries to find what might be wrong about
    

what s/he firmly believes*

[Rick Marken 2018-05-21_18:01:05]

[Martin Taylor 2018.05.18.12.46]

RM: An excellent treatise on the theory-only approach to PCT! Â >

···

Much, but not all, of the problem of long unresolved threads on CSGnet comes from misunderstandings about the intentions of the writers when using certain words and phrases. Other problems arise because each of us, novice or self-appointed expert, has a personal perception of what is and what is not "PCT", and of what consequences arise from that personal perception when it is applied to the real world. I doubt that any taxonomy could incorporate all the varieties that different CSGnet readers think of when they think "PCT", but it is possible to describe some variations that deserve the name.Â

A long time ago, in a mailing list far away, we had three classifications for variants of PCT. I forget the names we used, but in principle they were: Generic PCT, Generic Hierarchic PCT, and Bill Powers's specific version of Hierarchic PCT (HPCT). Some contributors to CSGnet now write assuming that Bill's HPCT was "PCT", as though the road to enlightenment was only through studying Bill's writings, despite the unavoidable self-contradictions that occur between his early and late writings. As should be the case for any good scientist, Bill's understanding of PCT developed, over the half-century and more that he studied the control of perception. To base discussions of PCT only on fine interpretations of Bill's writings, especially the earlier ones, is a sure way to create disputes. Just as an exhaustive study of any ancient writings by several people will do, the various Koranic, Biblical, or Talmudic scholars come to different conclusions about the truth that is hiding behind the Holy Writ of PCT.

My own preference is to work from the other end, to consider Nature, using my own interpretation of Bill's powerful insights as a valuable but not infallible guide. I ask questions such as: Supposing this or that variant form of PCT happened to be correct, what would we observe? What limitations does Nature impose on control, and is this or that version of PCT consistent with those limits? How could we know whether what we perceive has a counterpart in properties of the environment in which we live? Etc., etc... One class of questions concerns whether observed effects depend on Generic PCT, Generic hierarchic PCT, HPCT, or some other variant, of which there may be many.

What did we mean by these three levels so long ago? Generic PCT simply means a theory that organisms create internal variables that correspond to some patterns of sensory data based on things and events in the real environment, and act to influence those patterns to conform to internal "reference variables". Generic PCT specifies nothing about the form of these control loops or how one relates to another. They might all work independently, they might have all sorts of cross influences or network structures of interaction. Generic PCT allows almost anything that involves control of internal variables by action on the environment outside the organism.

Generic Hierarchic PCT (GHPCT) is a specific refinement of Generic PCT, one of many possible structures of interaction among control loops. The specific refinement is that the internal (perceptual) variables individually represent identifiable entities or structures in the environment. Those that are controlled come in simple and more complex forms, the more complex being built on the simpler to form a kind of "tower of complexity" with very complex perceptual forms at the top and raw sensory data at the base. GHPCT allows any kind of relationship among the functional processes that lead to control of these perceptions.

Powers's Hierarchic PCT (HPCT) is a specific refinement of GHPCT, in which different levels of complexity and a specific form of interconnections among the functional processes is defined. Although Powers did not insist on it (at least at the lowest levels), one might include as a necessary component of HPCT the eleven types of increasingly complex perception Powers proposed. Of course, I am not saying that Powers developed his version of PCT by refining GHPCT. Far from it. The reverse, a generalization from Powers's HPCT to GHPCT, would be nearer the truth.

Another way one might categorize varieties of PCT is according to how the PCT structures evolve over generations and within individuals. Among other possibilities, we might include e-coli reorganization, reinforcement learning, Hebbian cell-assembly and random connection making and breaking, all globally, in modules, or in hybrid form. Powers's HPCT incorporates e-coli reorganization generically, but not in any formal and specific way. Different variants of Powers's HPCT would depend on different understandings of how reorganization functions to change the control hierarchy.

Already we have listed over a dozen possible varieties of PCT, and these are far from exhaustive. For example, there are other species of GHPCT, and forms of Generic PCT that are highly structured but not hierarchic. I don't know whether anyone has seriously proposed the following as a PCT variety, but in the silico-acoustic world the inverse Fourier transform of the log Fourier transform is a useful tool. Imagine a model in which the controlled perceptions were quasi-spectral relationships among vectors of logarithmic values. Structurally, this kind of thing was proposed (a long time ago) for the distributed character of perceptions to protect them against focal brain damage, and maybe control of spectral representations might be functional. Many years ago, when I visited the Swedish Defence Research Institute I was shown how re-inverting the phase spectrum of a spatial Fourier transform after losing the amplitude information produced a good outline drawing of the original picture. Neural systems seem well suited to doing this kind of thing, but is it well suited to control in a dynamic environment? One could actually consider the plethora of specific perceptual functions of Powers's HPCT at a given level of the hierarchy as a kind of quasi-spectral transform, mathematically.

One specific variant of GHPCT that I do like is based on the apparently different functional tendencies of the brain hemispheres. This variant is like Powers's HPCT except that there is no category level as such. Instead, each of the other perceptual types may interface with a category process that produces category values and performs logical operations on them ( (left-brain function)) interacting with analogue values (right-brain function) at each level. Again, there are probably many variations on this theme, all producing different variant forms of PCT.

My main point is not to advocate for any changes to Powers's version of HPCT, but to show how easily variant forms can be imagined. This being the case, how many more subtly different varieties of PCT may exist in the hidden assumptions each of us has when we discuss "PCT" on CSGnet and get into unnecessary arguments. In most cases, so long as the assumptions remain hidden, arguments are unresolvable about what is or is not PCT and about what is or is not true of Nature viewed through a PCT lens. Even if by some lucky chance the conflicting assumptions are revealed, it is as like as not that no experiment has been done that could distinguish between them, and the only rationale for choosing one over the other would be Ockham's Razor -- and that particular razor shaves differently for different people (see <http://www.mmtaylor.net/Academic/ockham.html><http://www.mmtaylor.net/Academic/ockham.html> for the explanation).

My second point is simply to try to shake up a bit the idea that some people seem to hold, that "PCT" means exclusively the constellation of concepts about which Powers wrote. That happens to be the version of PCT that is by far the most studied and tested, but it is far from the only one that is possible, and many of the others would automatically have provided identical results to any tests that have as yet been applied to the Powers version, including all studies such as the Test for the Controlled Variable, which examine only a single isolated control loop.

Martin
"A good scientist always tries to find what might be wrong about what s/he firmly believes"

--
Richard S. MarkenÂ
"Perfection is achieved not when you have nothing more to add, but when you
have nothing left to take away.�
                --Antoine de Saint-Exupery

[Martin Taylor 2018.05.21.23.23]

Thank you. I will accept "excellent treatise" but I do not think it

is or was an approach to PCT of any kind, theory-only or scientific.

It is just a reminder of the wide scope of Perceptual Control

Theories, nothing more Such a reminder from time to time seems to be
needed, because people write as though they forget that the
fundamental claim that behaviour is the control of perception can be
the basis of many theories, and that no experiment of which I am
aware has yet distinguished among even some major classes of them.
The Test for the Controlled Variable, for example, works equally
well with all of them, as does any analysis that is concerned with
only a single control loop. The proper study of PCT is the
discrimination of the correct theory among the great range of
possible theories (assuming as I do that the correct theory is a
Perceptual Control Theory).

To make that discrimination requires either experiments that would

give results predicted differently by different theories, or
analyses of the theories that shows one or other of them to predict
results that are not in accordance with the body of science. Your
“hierarchies of perception” is such an experiment, since it argues
quite strongly against a “flat” version of PCT in which all
controlled perceptions are at the same level as each other. But
there aren’t many such experiments.

Martin
···

[Rick Marken 2018-05-21_18:01:05]

            [Martin Taylor

2018.05.18.12.46]

            RM:

An excellent treatise on the theory-only approach to
PCT! Â

            Much, but not all, of the problem of long unresolved

threads on CSGnet comes from misunderstandings about the
intentions of the writers when using certain words and
phrases. Other problems arise because each of us, novice
or self-appointed expert, has a personal perception of
what is and what is not “PCT”, and of what consequences
arise from that personal perception when it is applied
to the real world. I doubt that any taxonomy could
incorporate all the varieties that different CSGnet
readers think of when they think “PCT”, but it is
possible to describe some variations that deserve the
name.Â

            A long time ago, in a mailing list far away, we had

three classifications for variants of PCT. I forget the
names we used, but in principle they were: Generic PCT,
Generic Hierarchic PCT, and Bill Powers’s specific
version of Hierarchic PCT (HPCT). Some contributors to
CSGnet now write assuming that Bill’s HPCT was “PCT”, as
though the road to enlightenment was only through
studying Bill’s writings, despite the unavoidable
self-contradictions that occur between his early and
late writings. As should be the case for any good
scientist, Bill’s understanding of PCT developed, over
the half-century and more that he studied the control of
perception. To base discussions of PCT only on fine
interpretations of Bill’s writings, especially the
earlier ones, is a sure way to create disputes. Just as
an exhaustive study of any ancient writings by several
people will do, the various Koranic, Biblical, or
Talmudic scholars come to different conclusions about
the truth that is hiding behind the Holy Writ of PCT.

            My own preference is to work from the other end, to

consider Nature, using my own interpretation of Bill’s
powerful insights as a valuable but not infallible
guide. I ask questions such as: Supposing this or that
variant form of PCT happened to be correct, what would
we observe? What limitations does Nature impose on
control, and is this or that version of PCT consistent
with those limits? How could we know whether what we
perceive has a counterpart in properties of the
environment in which we live? Etc., etc… One class of
questions concerns whether observed effects depend on
Generic PCT, Generic hierarchic PCT, HPCT, or some other
variant, of which there may be many.

            What did we mean by these three levels so long ago?

Generic PCT simply means a theory that organisms create
internal variables that correspond to some patterns of
sensory data based on things and events in the real
environment, and act to influence those patterns to
conform to internal “reference variables”. Generic PCT
specifies nothing about the form of these control loops
or how one relates to another. They might all work
independently, they might have all sorts of cross
influences or network structures of interaction. Generic
PCT allows almost anything that involves control of
internal variables by action on the environment outside
the organism.

            Generic Hierarchic PCT (GHPCT) is a specific refinement

of Generic PCT, one of many possible structures of
interaction among control loops. The specific refinement
is that the internal (perceptual) variables individually
represent identifiable entities or structures in the
environment. Those that are controlled come in simple
and more complex forms, the more complex being built on
the simpler to form a kind of “tower of complexity” with
very complex perceptual forms at the top and raw sensory
data at the base. GHPCT allows any kind of relationship
among the functional processes that lead to control of
these perceptions.

            Powers's Hierarchic PCT (HPCT) is a specific refinement

of GHPCT, in which different levels of complexity and a
specific form of interconnections among the functional
processes is defined. Although Powers did not insist on
it (at least at the lowest levels), one might include as
a necessary component of HPCT the eleven types of
increasingly complex perception Powers proposed. Of
course, I am not saying that Powers developed his
version of PCT by refining GHPCT. Far from it. The
reverse, a generalization from Powers’s HPCT to GHPCT,
would be nearer the truth.

            Another way one might categorize varieties of PCT is

according to how the PCT structures evolve over
generations and within individuals. Among other
possibilities, we might include e-coli reorganization,
reinforcement learning, Hebbian cell-assembly and random
connection making and breaking, all globally, in
modules, or in hybrid form. Powers’s HPCT incorporates
e-coli reorganization generically, but not in any formal
and specific way. Different variants of Powers’s HPCT
would depend on different understandings of how
reorganization functions to change the control
hierarchy.

            Already we have listed over a dozen possible varieties

of PCT, and these are far from exhaustive. For example,
there are other species of GHPCT, and forms of Generic
PCT that are highly structured but not hierarchic. I
don’t know whether anyone has seriously proposed the
following as a PCT variety, but in the silico-acoustic
world the inverse Fourier transform of the log Fourier
transform is a useful tool. Imagine a model in which the
controlled perceptions were quasi-spectral relationships
among vectors of logarithmic values. Structurally, this
kind of thing was proposed (a long time ago) for the
distributed character of perceptions to protect them
against focal brain damage, and maybe control of
spectral representations might be functional. Many years
ago, when I visited the Swedish Defence Research
Institute I was shown how re-inverting the phase
spectrum of a spatial Fourier transform after losing the
amplitude information produced a good outline drawing
of the original picture. Neural systems seem well
suited to doing this kind of thing, but is it well
suited to control in a dynamic environment? One could
actually consider the plethora of specific perceptual
functions of Powers’s HPCT at a given level of the
hierarchy as a kind of quasi-spectral transform,
mathematically.

            One specific variant of GHPCT that I do like is based on

the apparently different functional tendencies of the
brain hemispheres. This variant is like Powers’s HPCT
except that there is no category level as such. Instead,
each of the other perceptual types may interface with a
category process that produces category values and
performs logical operations on them ( (left-brain
function)) interacting with analogue values (right-brain
function) at each level. Again, there are probably many
variations on this theme, all producing different
variant forms of PCT.

            My main point is not to advocate for any changes to

Powers’s version of HPCT, but to show how easily variant
forms can be imagined. This being the case, how many
more subtly different varieties of PCT may exist in the
hidden assumptions each of us has when we discuss “PCT”
on CSGnet and get into unnecessary arguments. In most
cases, so long as the assumptions remain hidden,
arguments are unresolvable about what is or is not PCT
and about what is or is not true of Nature viewed
through a PCT lens. Even if by some lucky chance the
conflicting assumptions are revealed, it is as like as
not that no experiment has been done that could
distinguish between them, and the only rationale for
choosing one over the other would be Ockham’s Razor –
and that particular razor shaves differently for
different people (see http://www.mmtaylor.net/Academic/ockham.html
for the explanation).

            My second point is simply to try to shake up a bit the

idea that some people seem to hold, that “PCT” means
exclusively the constellation of concepts about which
Powers wrote. That happens to be the version of PCT that
is by far the most studied and tested, but it is far
from the only one that is possible, and many of the
others would automatically have provided identical
results to any tests that have as yet been applied to
the Powers version, including all studies such as the
Test for the Controlled Variable, which examine only a
single isolated control loop.

            Martin
            "*                  A good scientist always tries to find what might be

wrong about what s/he firmly believes*"

Richard S. MarkenÂ

                                  "Perfection

is achieved not when you have
nothing more to add, but when you
have
nothing left to take away.�
  Â
            Â
–Antoine de Saint-Exupery