A/symmetry of control (was Re: Causality (was Re: Behavioural Illusion))

[EetuP]

[Eetu Pikkarainen 2017-10-13 2]

Wow Martin, that
[Martin Taylor 2017.10.10.13.31] was really impressive. I quote it wholly before my new text. I change again the title.

MT: Your mention of varying the reference value, whereas we have been talking about conditions in which only the disturbance changes, brings up another way to think of overt and masked causality.
The masked causality is the ring of causal connections the together form the loop, which is masked because he feedback tends to bring the whole ring back toward the state it was in before the external event (disturbance
or reference change). The overt causality is that between the reference value and the value of the CEV in the environment. A change in reference value changes the value of the CEV, mediated by the ring’s masked causality. The clearer the overt causality, which
is the way the controller “imposes its will on the universe”, the more strongly masked is the ring set of causal connections.
MT: If you look simply at a canonical loop diagram, the relation between the reference and the CEV is symmetric with the relation between the disturbance and the perception.
So why does there seem to be an overt causality between reference and CEV, whereas the causal relation between disturbance and perception is masked and not obvious? (If it were obvious, this discussion would never have
existed and the long-running “Rick against the unseeing world” saga would not have this chapter – in which Bill P was part of “the unseeing world” who insist that normal causality operates throughout the control of perception).
MT: The canonical diagram may look symmetrical, but it isn’t.
The gain on the output side is, and must be, much greater than that on the input (perceptual) side. Both dynamically and in the asymptotic equilibrium state that difference is the only reason why the reference-to-CEV
causality is more obvious than the disturbance-to-perception causality. As Bruce Abbott has pointed out, the causal effect of a step change in the disturbance is fully apparent at the perception until at least one loop transport delay later, and remains partly
effective for an appreciable time thereafter, forever if the output function is a leaky integrator.
MT: The idea of causality is itself a gross simplification of the very high-dimensional flow of state through an unimaginably large Universe, but so long as we use the word as a linguistic convenience, we
might as well try to use it somewhat consistently. In particular, so long as we are working on time and distance scales where relativistic effects are trivially small, then if A occurs before B we should not say B causes
A. Nor should we ever say that A is the only cause of B without specifying other conditions that surround the two events.

EP (from now on): I started to think about that symmetry / asymmetry question which has intrigued me also earlier. To make it more clear is draw this funny symmetric diagram which can turned around if you wish:

This is not very adequate and perfect diagram because the wire labels and functions are not differentiated. The boxes are rather just points in the diagram. (Label “C� has vanished in conversion.) I try next describe
what I mean with these points by starting randomly from A and assuming that subject is above and environment below the vague blue line.

signals but they have an average strength which depends (among others) on the strength of the original effect. The signal branches to B and C.

B: If the controller is an elementary control unit then the perceptual signal is sent at least to some other units above it in the control hierarchy. If the controller is a highest unit in the hierarchy or the diagram
depicts the whole subject as one control system then this branch is probably missing.

C: (Empty box in the picture.) This is the comparator function where the perceptual and reference signals are compared and the error signal produced as a difference (remainder) between perceptual and reference signals.

D: This box refers to some other control units which are higher in the hierarchy. They send their output as reference signals to C. The signals they send can have combined effects and in the case of internal conflict
they can more or less cancel each other (see Powers: MSB p.74-).

E: Here is the output function which is a kind of an amplifier. It converts the error signal to some kind of environmental force as an output. The strength of the output depends on the strength of the error but is amplified
or gained(?). It can typically also realize a time integration so that the force of the output grows from zero (or earlier output level) gradually and continues growing as long as the error remains.

F: This is usually called the environmental feedback function. I understand that it means the environmental causal chain through which the effects of the output is mediated forward inside the loop. I guess the nature
of this chain can increase or decrease the loop gain so that certain kind of chain can enable stronger consequences with less output. For example tools can be such mediators, or feedback links.

G: This box refers to (immediate) side-effects of the output. In a way these immediate side-effects lessen the efficacy of the output as a wasted energy. But there are also mediated side-effects: the output changes the
situations in the environment and thus the conditions of many (all?) environmental processes will change which can more or less turn the course of those processes away from what they had been if that output had not happened. (“Everything affects everything.�)

H: This is the CEV or the complex environmental variable which (presumably) corresponds to (and is responsible for) the environmental effect which is converted to perceptual signal in A. This variable is a (possibly complex)
feature of one object or of a complex of objects. The feedback chain consists of objects whose certain properties make them interact together and thus form the links of the chain and CEV is one of these links.

I: Here are the incoming branches of the feedback chain and they together form the disturbance. The value of CEV is determined by the combined effects of all these branches and the output. Here like with references these
disturbance effects can strengthen or weaken each other. They typically are thought to be opposite to the output but some effects can also be concurrent and thus strengthen the effect of output to the CEV.

J: This is not usually drawn in PCT diagrams. This is the end of the feedback chain which happens to be after the CEV. For example these links could be something like newspaper, mirror, microscope or any other mediators
or chains of mediators via which the effect of the CEV receives the controller. Sometimes there is perhaps none. F and J could be called the output part of the feedback chain and the input part of the feedback chain, respectively.

Now if we look at the seeming symmetry of the loop: C and H with incoming branches are very similar, only error is the (theoretical) sign conversion in C. Practically this sign conversion seems to happen more in the environmental
side. (?) A and F with outgoing branches are very similar. The biggest apparent difference is between E and J. For E it is important that it amplifies the signal strongly enough. Instead for J it is important that it does NOT change too much and distort the
original effect of the CEV.

This is the formal answer to my old problem what justifies that in the theory of action we look at the interaction between subject and environment from the point of view of the subject.

Eetu

Please, regard all my statements as questions,

no matter how they are formulated.

[EetuP]

[Eetu Pikkarainen 2018-10-14]

Oops, Sorry, an important mistake. I should have mentioned that while upper side of the loop consists on quite homogeneous nerve “wires” the lower side is made from very heterogeneous physical cause-effect chains. So for example there is an important difference
between perception branch and side effects branches. Earlier is a copy of the signal in the loop but latter is probably not similar with the output.

Good weekend!

Eetu
(Lähetetty kännykästä / Sent from mobile)

···

Eetu Pikkarainen eetu.pikkarainen@oulu.fi kirjoitti 13.10.2017 kello 22.03:

[Eetu Pikkarainen 2017-10-13 2]

Wow Martin, that
[Martin Taylor 2017.10.10.13.31] was really impressive. I quote it wholly before my new text. I change again the title.

MT: Your mention of varying the reference value, whereas we have been talking about conditions in which only the disturbance changes, brings up another way to think of overt and masked causality.
The masked causality is the ring of causal connections the together form the loop, which is masked because he feedback tends to bring the whole ring back toward the state it was in before the external event (disturbance
or reference change). The overt causality is that between the reference value and the value of the CEV in the environment. A change in reference value changes the value of the CEV, mediated by the ring’s masked causality. The clearer the overt causality, which
is the way the controller “imposes its will on the universe”, the more strongly masked is the ring set of causal connections.
MT: If you look simply at a canonical loop diagram, the relation between the reference and the CEV is symmetric with the relation between the disturbance and the perception.
So why does there seem to be an overt causality between reference and CEV, whereas the causal relation between disturbance and perception is masked and not obvious? (If it were obvious, this discussion would never have
existed and the long-running “Rick against the unseeing world” saga would not have this chapter – in which Bill P was part of “the unseeing world” who insist that normal causality operates throughout the control of perception).
MT: The canonical diagram may look symmetrical, but it isn’t.
The gain on the output side is, and must be, much greater than that on the input (perceptual) side. Both dynamically and in the asymptotic equilibrium state that difference is the only reason why the reference-to-CEV
causality is more obvious than the disturbance-to-perception causality. As Bruce Abbott has pointed out, the causal effect of a step change in the disturbance is fully apparent at the perception until at least one loop transport delay later, and remains partly
effective for an appreciable time thereafter, forever if the output function is a leaky integrator.
MT: The idea of causality is itself a gross simplification of the very high-dimensional flow of state through an unimaginably large Universe, but so long as we use the word as a linguistic convenience, we
might as well try to use it somewhat consistently. In particular, so long as we are working on time and distance scales where relativistic effects are trivially small, then if A occurs before B we should not say B causes
A. Nor should we ever say that A is the only cause of B without specifying other conditions that surround the two events.

EP (from now on): I started to think about that symmetry / asymmetry question which has intrigued me also earlier. To make it more clear is draw this funny symmetric diagram which can turned around if you wish:

<image003.png>

This is not very adequate and perfect diagram because the wire labels and functions are not differentiated. The boxes are rather just points in the diagram. (Label “C” has vanished in conversion.) I try next describe
what I mean with these points by starting randomly from A and assuming that subject is above and environment below the vague blue line.

A: Here is the perceptual function which converts some environmental effect (stimulus, irritation) to a perceptual nervous signal which is then sent forward via probably many nerves. The individual nerves can carry different
signals but they have an average strength which depends (among others) on the strength of the original effect. The signal branches to B and C.

B: If the controller is an elementary control unit then the perceptual signal is sent at least to some other units above it in the control hierarchy. If the controller is a highest unit in the hierarchy or the diagram
depicts the whole subject as one control system then this branch is probably missing.

C: (Empty box in the picture.) This is the comparator function where the perceptual and reference signals are compared and the error signal produced as a difference (remainder) between perceptual and reference signals.

D: This box refers to some other control units which are higher in the hierarchy. They send their output as reference signals to C. The signals they send can have combined effects and in the case of internal conflict
they can more or less cancel each other (see Powers: MSB p.74-).

E: Here is the output function which is a kind of an amplifier. It converts the error signal to some kind of environmental force as an output. The strength of the output depends on the strength of the error but is amplified
or gained(?). It can typically also realize a time integration so that the force of the output grows from zero (or earlier output level) gradually and continues growing as long as the error remains.

F: This is usually called the environmental feedback function. I understand that it means the environmental causal chain through which the effects of the output is mediated forward inside the loop. I guess the nature
of this chain can increase or decrease the loop gain so that certain kind of chain can enable stronger consequences with less output. For example tools can be such mediators, or feedback links.

G: This box refers to (immediate) side-effects of the output. In a way these immediate side-effects lessen the efficacy of the output as a wasted energy. But there are also mediated side-effects: the output changes the
situations in the environment and thus the conditions of many (all?) environmental processes will change which can more or less turn the course of those processes away from what they had been if that output had not happened. (“Everything affects everything.”)

H: This is the CEV or the complex environmental variable which (presumably) corresponds to (and is responsible for) the environmental effect which is converted to perceptual signal in A. This variable is a (possibly complex)
feature of one object or of a complex of objects. The feedback chain consists of objects whose certain properties make them interact together and thus form the links of the chain and CEV is one of these links.

I: Here are the incoming branches of the feedback chain and they together form the disturbance. The value of CEV is determined by the combined effects of all these branches and the output. Here like with references these
disturbance effects can strengthen or weaken each other. They typically are thought to be opposite to the output but some effects can also be concurrent and thus strengthen the effect of output to the CEV.

J: This is not usually drawn in PCT diagrams. This is the end of the feedback chain which happens to be after the CEV. For example these links could be something like newspaper, mirror, microscope or any other mediators
or chains of mediators via which the effect of the CEV receives the controller. Sometimes there is perhaps none. F and J could be called the output part of the feedback chain and the input part of the feedback chain, respectively.

Now if we look at the seeming symmetry of the loop: C and H with incoming branches are very similar, only error is the (theoretical) sign conversion in C. Practically this sign conversion seems to happen more in the environmental
side. (?) A and F with outgoing branches are very similar. The biggest apparent difference is between E and J. For E it is important that it amplifies the signal strongly enough. Instead for J it is important that it does NOT change too much and distort the
original effect of the CEV.

This is the formal answer to my old problem what justifies that in the theory of action we look at the interaction between subject and environment from the point of view of the subject.

Eetu

Please, regard all my statements as questions,

no matter how they are formulated.

[MartinT]

Martin Taylor 2017.10.14.07.48]

[Eetu Pikkarainen 2018-10-14]

    Oops, Sorry, an important mistake. I should have mentioned

that while upper side of the loop consists on quite homogeneous
nerve “wires” the lower side is made from very heterogeneous
physical cause-effect chains. So for example there is an
important difference between perception branch and side effects
branches. Earlier is a copy of the signal in the loop but latter
is probably not similar with the output.

It's not an important mistake. I don't think it was a mistake at all

to ignore the physical mechanism when one is trying to understand
function. The mechanism is relevant when you want to look at
specific control loops, but not when you are talking about
properties of control loops in general.

Here's a "Rube Goldberg" control loop -- Heath Robinson, for UK

readers. Both of them dreamed up ridiculously complicated (and
funny) mechanisms for performing very simple tasks.

![RubeGoldbergController.jpg|639x503](upload://736ev754WWYIiVPSsHx6TvGdk3U.jpeg)

This loop controls the angle of the scale arm. A pointer arm is

attached at right angles to it, so the position of the tip is
equivalent to a perception of the actual angle of the scale arm. It
has a reference value that is adjustable by moving the microswitch
(left and right in the picture). When the “Scale weight” is heavier
than the “Sand” weight, the arm angle changes, moving the pointer
tip (the perception), and
the switch (comparator) turns on the “Red Light” (beginning the
output side of the control loop). Continuing the output side, the
red light is sensed by a device that turns on a magnet that opens
doors on a water-gate. The water flow drives a water-wheel which is
connected to a belt that delivers sand. When the sand has piled up
enough, it will become heavier than the weight on the scale pan and
the microswitch will turn off the red light, stopping the
water-wheel and the flow of sand. Over time, the sand leaks through
holes in its pan, and at after a while the scale weight will again
be heavier than the sand pan.

The required asymmetry between input (perceptual) side and output

(action side) appears here. It doesn’t matter whether you consider
the environment to include the water gate and sand belt, or whether
you consider them to be internal parts of the controller. They are
part of the environmental feedback path from the comparator to the
CEV. You could take the shining of the red light to be the actual
output, or the opening of the water gate, or the delivery of the
sand. It doesn’t matter to the loop function. In the usual
hierarchy, very little energy is expended in passing reference
values from higher to lower levels down the output side, The main
energy use comes from the muscles and the machinery in the
environment. That’s where the power gain in the loop occurs, no
matter what values are passed between the levels.

The CEV is the angle of the scale arm. When the CEV changes, it

provides very little energy to move the scale pointer tip
(perception) relative to the microswitch location (comparator). In
contrast, it takes quite a lot of energy to move the water doors and
to move the sand (output stages). This controller is what is
sometimes called a “bang-bang” controller, like a thermostat,
because the comparator function has only two values “too heavy” or
“too light”, so you can’t measure numerical gains round the loop,
but the principles are the same. The controller even has an leaky
integrator output stage.

The point of this Rube Goldberg device is to illustrate the

independence of the control concept from the physical manifestation
of its functional components. It doesn’t incorporate your effects on
higher-level perceptions and other parts of the external
environment, but it does show the important thing. If the scale
pointer needed a lot of energy to move it when the sand had mostly
leaked away, the loop would not function well. It works best when
the pointer is very delicate and the microswitch needs only a
feather-touch to switch it on. But it also works best when the water
moves the wheel powerfully, delivering sand fast, and when the sand
also leaks fast but not as fast as it is delivered (the asymptotic
“gain” of a leaky integrator is the ratio of the gain rate and the
leak rate of the integrator).

Martin

···

Eetu Pikkarainen <eetu.pikkarainen@oulu.fi >
kirjoitti 13.10.2017 kello 22.03:

              [Eetu Pikkarainen

2017-10-13 2]

              Wow

Martin, that
[Martin Taylor
2017.10.10.13.31] was really impressive. I quote it
wholly before my new text. I change again the title.

              MT:                     Your mention of varying

the reference value, whereas we have been talking
about conditions in which only the disturbance
changes, brings up another way to think of overt and
masked causality.
The masked
causality is the ring of causal connections the
together form the loop, which is masked because he
feedback tends to bring the whole ring back toward the
state it was in before the external event (disturbance
or reference change). The overt causality is that
between the reference value and the value of the CEV
in the environment. A change in reference value
changes the value of the CEV, mediated by the ring’s
masked causality. The clearer the overt causality,
which is the way the controller “imposes its will on
the universe”, the more strongly masked is the ring
set of causal connections.

            MT:                     If

you look simply at a canonical loop diagram, the
relation between the reference and the CEV is
symmetric with the relation between the disturbance
and the perception.
So why does
there seem to be an overt causality between reference
and CEV, whereas the causal relation between
disturbance and perception is masked and not obvious?
(If it were obvious, this discussion would never have
existed and the long-running “Rick against the
unseeing world” saga would not have this chapter – in
which Bill P was part of “the unseeing world” who
insist that normal causality operates throughout the
control of perception).

            MT:                     The

canonical diagram may look symmetrical, but it
isn’t.
The gain on
the output side is, and must be, much greater than
that on the input (perceptual) side. Both dynamically
and in the asymptotic equilibrium state that
difference is the only reason why the reference-to-CEV
causality is more obvious than the
disturbance-to-perception causality. As Bruce Abbott
has pointed out, the causal effect of a step change in
the disturbance is fully apparent at the perception
until at least one loop transport delay later, and
remains partly effective for an appreciable time
thereafter, forever if the output function is a leaky
integrator.

            MT:                     The

idea of causality is itself a gross simplification
of the very high-dimensional flow of state through
an unimaginably large Universe, but so long as we
use the word as a linguistic convenience, we might
as well try to use it somewhat consistently. In particular, so long as we are
working on time and distance scales where relativistic
effects are trivially small, then if A occurs before B
we should not say B causes A. Nor should we ever say
that A is the only cause of B without
specifying other conditions that surround the two
events.

              EP (from now on):

I started to think about that symmetry / asymmetry
question which has intrigued me also earlier. To make
it more clear is draw this funny symmetric diagram
which can turned around if you wish:

<image003.png>

              This is not very

adequate and perfect diagram because the wire labels
and functions are not differentiated. The boxes are
rather just points in the diagram. (Label “C” has
vanished in conversion.) I try next describe what I
mean with these points by starting randomly from A and
assuming that subject is above and environment below
the vague blue line.

              A: Here is the

perceptual function which converts some environmental
effect (stimulus, irritation) to a perceptual nervous
signal which is then sent forward via probably many
nerves. The individual nerves can carry different
signals but they have an average strength which
depends (among others) on the strength of the original
effect. The signal branches to B and C.

              B: If the

controller is an elementary control unit then the
perceptual signal is sent at least to some other units
above it in the control hierarchy. If the controller
is a highest unit in the hierarchy or the diagram
depicts the whole subject as one control system then
this branch is probably missing.

              C: (Empty box in

the picture.) This is the comparator function where
the perceptual and reference signals are compared and
the error signal produced as a difference (remainder)
between perceptual and reference signals.

              D: This box refers

to some other control units which are higher in the
hierarchy. They send their output as reference signals
to C. The signals they send can have combined effects
and in the case of internal conflict they can more or
less cancel each other (see Powers: MSB p.74-).

              E: Here is the

output function which is a kind of an amplifier. It
converts the error signal to some kind of
environmental force as an output. The strength of the
output depends on the strength of the error but is
amplified or gained(?). It can typically also realize
a time integration so that the force of the output
grows from zero (or earlier output level) gradually
and continues growing as long as the error remains.

              F: This is usually

called the environmental feedback function. I
understand that it means the environmental causal
chain through which the effects of the output is
mediated forward inside the loop. I guess the nature
of this chain can increase or decrease the loop gain
so that certain kind of chain can enable stronger
consequences with less output. For example tools can
be such mediators, or feedback links.

              G: This box refers

to (immediate) side-effects of the output. In a way
these immediate side-effects lessen the efficacy of
the output as a wasted energy. But there are also
mediated side-effects: the output changes the
situations in the environment and thus the conditions
of many (all?) environmental processes will change
which can more or less turn the course of those
processes away from what they had been if that output
had not happened. (“Everything affects everything.”)

              H: This is the CEV

or the complex environmental variable which
(presumably) corresponds to (and is responsible for)
the environmental effect which is converted to
perceptual signal in A. This variable is a (possibly
complex) feature of one object or of a complex of
objects. The feedback chain consists of objects whose
certain properties make them interact together and
thus form the links of the chain and CEV is one of
these links.

              I: Here are the

incoming branches of the feedback chain and they
together form the disturbance. The value of CEV is
determined by the combined effects of all these
branches and the output. Here like with references
these disturbance effects can strengthen or weaken
each other. They typically are thought to be opposite
to the output but some effects can also be concurrent
and thus strengthen the effect of output to the CEV.

              J: This is not

usually drawn in PCT diagrams. This is the end of the
feedback chain which happens to be after the CEV. For
example these links could be something like newspaper,
mirror, microscope or any other mediators or chains of
mediators via which the effect of the CEV receives the
controller. Sometimes there is perhaps none. F and J
could be called the output part of the feedback chain
and the input part of the feedback chain,
respectively.

              Now if we look at

the seeming symmetry of the loop: C and H with
incoming branches are very similar, only error is the
(theoretical) sign conversion in C. Practically this
sign conversion seems to happen more in the
environmental side. (?) A and F with outgoing branches
are very similar. The biggest apparent difference is
between E and J. For E it is important that it
amplifies the signal strongly enough. Instead for J it
is important that it does NOT change too much and
distort the original effect of the CEV.

              This is the formal

answer to my old problem what justifies that in the
theory of action we look at the interaction between
subject and environment from the point of view of the
subject.

Eetu

Please, regard all my statements as questions,

              no

matter how they are formulated.

[EetuP]

[Eetu Pikkarainen 2017-10-14 2]

I got it. The most important asymmetry is not between upper subject side and lower environment side but between left low energy side and right higher energy side. Right?

Eetu
(Lähetetty kännykästä / Sent from mobile)

···

Martin Taylor mmt-csg@mmtaylor.net kirjoitti 14.10.2017 kello 15.58:

Martin Taylor 2017.10.14.07.48]

[Eetu Pikkarainen 2018-10-14]

Oops, Sorry, an important mistake. I should have mentioned that while upper side of the loop consists on quite homogeneous nerve “wires� the lower side is made from very heterogeneous physical cause-effect chains. So for example there is an important difference
between perception branch and side effects branches. Earlier is a copy of the signal in the loop but latter is probably not similar with the output.

It’s not an important mistake. I don’t think it was a mistake at all to ignore the physical mechanism when one is trying to understand function. The mechanism is relevant when you want to look at specific control loops, but not when you are talking about properties
of control loops in general.

Here’s a “Rube Goldberg” control loop – Heath Robinson, for UK readers. Both of them dreamed up ridiculously complicated (and funny) mechanisms for performing very simple tasks.

<RubeGoldbergController.jpg>

This loop controls the angle of the scale arm. A pointer arm is attached at right angles to it, so the position of the tip is equivalent to a perception of the actual angle of the scale arm. It has a reference value that is adjustable by moving the microswitch
(left and right in the picture). When the “Scale weight” is heavier than the “Sand” weight, the arm angle changes, moving the pointer tip (the perception), and the switch (comparator) turns on the “Red Light” (beginning the output side of the control loop).
Continuing the output side, the red light is sensed by a device that turns on a magnet that opens doors on a water-gate. The water flow drives a water-wheel which is connected to a belt that delivers sand. When the sand has piled up enough, it will become
heavier than the weight on the scale pan and the microswitch will turn off the red light, stopping the water-wheel and the flow of sand. Over time, the sand leaks through holes in its pan, and at after a while the scale weight will again be heavier than the
sand pan.

The required asymmetry between input (perceptual) side and output (action side) appears here. It doesn’t matter whether you consider the environment to include the water gate and sand belt, or whether you consider them to be internal parts of the controller.
They are part of the environmental feedback path from the comparator to the CEV. You could take the shining of the red light to be the actual output, or the opening of the water gate, or the delivery of the sand. It doesn’t matter to the loop function. In
the usual hierarchy, very little energy is expended in passing reference values from higher to lower levels down the output side, The main energy use comes from the muscles and the machinery in the environment. That’s where the power gain in the loop occurs,
no matter what values are passed between the levels.

The CEV is the angle of the scale arm. When the CEV changes, it provides very little energy to move the scale pointer tip (perception) relative to the microswitch location (comparator). In contrast, it takes quite a lot of energy to move the water doors and
to move the sand (output stages). This controller is what is sometimes called a “bang-bang” controller, like a thermostat, because the comparator function has only two values “too heavy” or “too light”, so you can’t measure numerical gains round the loop,
but the principles are the same. The controller even has an leaky integrator output stage.

The point of this Rube Goldberg device is to illustrate the independence of the control concept from the physical manifestation of its functional components. It doesn’t incorporate your effects on higher-level perceptions and other parts of the external environment,
but it does show the important thing. If the scale pointer needed a lot of energy to move it when the sand had mostly leaked away, the loop would not function well. It works best when the pointer is very delicate and the microswitch needs only a feather-touch
to switch it on. But it also works best when the water moves the wheel powerfully, delivering sand fast, and when the sand also leaks fast but not as fast as it is delivered (the asymptotic “gain” of a leaky integrator is the ratio of the gain rate and the
leak rate of the integrator).

Martin

Good weekend!

Eetu
(Lähetetty kännykästä / Sent from mobile)

Eetu Pikkarainen eetu.pikkarainen@oulu.fi kirjoitti 13.10.2017 kello 22.03:

[Eetu Pikkarainen 2017-10-13 2]

Wow Martin, that
[Martin Taylor 2017.10.10.13.31] was really impressive. I quote it wholly before my new text. I change again the title.

MT: Your mention of varying the reference value, whereas we have been talking about conditions in which only the disturbance changes, brings up another way to think of overt and masked causality.
The masked causality is the ring of causal connections the together form the loop, which is masked because he feedback tends to bring the whole ring back toward the state it was in before the external event (disturbance
or reference change). The overt causality is that between the reference value and the value of the CEV in the environment. A change in reference value changes the value of the CEV, mediated by the ring’s masked causality. The clearer the overt causality, which
is the way the controller “imposes its will on the universe”, the more strongly masked is the ring set of causal connections.
MT: If you look simply at a canonical loop diagram, the relation between the reference and the CEV is symmetric with the relation between the disturbance and the perception.
So why does there seem to be an overt causality between reference and CEV, whereas the causal relation between disturbance and perception is masked and not obvious? (If it were obvious, this discussion would never have
existed and the long-running “Rick against the unseeing world” saga would not have this chapter – in which Bill P was part of “the unseeing world” who insist that normal causality operates throughout the control of perception).
MT: The canonical diagram may look symmetrical, but it isn’t.
The gain on the output side is, and must be, much greater than that on the input (perceptual) side. Both dynamically and in the asymptotic equilibrium state that difference is the only reason why the reference-to-CEV
causality is more obvious than the disturbance-to-perception causality. As Bruce Abbott has pointed out, the causal effect of a step change in the disturbance is fully apparent at the perception until at least one loop transport delay later, and remains partly
effective for an appreciable time thereafter, forever if the output function is a leaky integrator.
MT: The idea of causality is itself a gross simplification of the very high-dimensional flow of state through an unimaginably large Universe, but so long as we use the word as a linguistic convenience, we
might as well try to use it somewhat consistently. In particular, so long as we are working on time and distance scales where relativistic effects are trivially small, then if A occurs before B we should not say B causes
A. Nor should we ever say that A is the only cause of B without specifying other conditions that surround the two events.

EP (from now on): I started to think about that symmetry / asymmetry question which has intrigued me also earlier. To make it more clear is draw this funny symmetric diagram which can turned around if you wish:

<image003.png>

This is not very adequate and perfect diagram because the wire labels and functions are not differentiated. The boxes are rather just points in the diagram. (Label “C� has vanished in conversion.) I try next describe
what I mean with these points by starting randomly from A and assuming that subject is above and environment below the vague blue line.

A: Here is the perceptual function which converts some environmental effect (stimulus, irritation) to a perceptual nervous signal which is then sent forward via probably many nerves. The individual nerves can carry different
signals but they have an average strength which depends (among others) on the strength of the original effect. The signal branches to B and C.

B: If the controller is an elementary control unit then the perceptual signal is sent at least to some other units above it in the control hierarchy. If the controller is a highest unit in the hierarchy or the diagram
depicts the whole subject as one control system then this branch is probably missing.

C: (Empty box in the picture.) This is the comparator function where the perceptual and reference signals are compared and the error signal produced as a difference (remainder) between perceptual and reference signals.

D: This box refers to some other control units which are higher in the hierarchy. They send their output as reference signals to C. The signals they send can have combined effects and in the case of internal conflict
they can more or less cancel each other (see Powers: MSB p.74-).

E: Here is the output function which is a kind of an amplifier. It converts the error signal to some kind of environmental force as an output. The strength of the output depends on the strength of the error but is amplified
or gained(?). It can typically also realize a time integration so that the force of the output grows from zero (or earlier output level) gradually and continues growing as long as the error remains.

F: This is usually called the environmental feedback function. I understand that it means the environmental causal chain through which the effects of the output is mediated forward inside the loop. I guess the nature
of this chain can increase or decrease the loop gain so that certain kind of chain can enable stronger consequences with less output. For example tools can be such mediators, or feedback links.

G: This box refers to (immediate) side-effects of the output. In a way these immediate side-effects lessen the efficacy of the output as a wasted energy. But there are also mediated side-effects: the output changes the
situations in the environment and thus the conditions of many (all?) environmental processes will change which can more or less turn the course of those processes away from what they had been if that output had not happened. (“Everything affects everything.�)

H: This is the CEV or the complex environmental variable which (presumably) corresponds to (and is responsible for) the environmental effect which is converted to perceptual signal in A. This variable is a (possibly complex)
feature of one object or of a complex of objects. The feedback chain consists of objects whose certain properties make them interact together and thus form the links of the chain and CEV is one of these links.

I: Here are the incoming branches of the feedback chain and they together form the disturbance. The value of CEV is determined by the combined effects of all these branches and the output. Here like with references these
disturbance effects can strengthen or weaken each other. They typically are thought to be opposite to the output but some effects can also be concurrent and thus strengthen the effect of output to the CEV.

J: This is not usually drawn in PCT diagrams. This is the end of the feedback chain which happens to be after the CEV. For example these links could be something like newspaper, mirror, microscope or any other mediators
or chains of mediators via which the effect of the CEV receives the controller. Sometimes there is perhaps none. F and J could be called the output part of the feedback chain and the input part of the feedback chain, respectively.

Now if we look at the seeming symmetry of the loop: C and H with incoming branches are very similar, only error is the (theoretical) sign conversion in C. Practically this sign conversion seems to happen more in the environmental
side. (?) A and F with outgoing branches are very similar. The biggest apparent difference is between E and J. For E it is important that it amplifies the signal strongly enough. Instead for J it is important that it does NOT change too much and distort the
original effect of the CEV.

This is the formal answer to my old problem what justifies that in the theory of action we look at the interaction between subject and environment from the point of view of the subject.

Eetu

Please, regard all my statements as questions,

no matter how they are formulated.

[MartinT]

[Martin Taylor 2017.10.14.14.56]

[Eetu Pikkarainen 2017-10-14 2]

    I got it. The most important asymmetry is not between upper

subject side and lower environment side but between left low
energy side and right higher energy side. Right?

Yes, if you are concerned with how the loop functions.

Martin

···

Martin Taylor <mmt-csg@mmtaylor.net >
kirjoitti 14.10.2017 kello 15.58:

Martin Taylor 2017.10.14.07.48]

          [Eetu

Pikkarainen 2018-10-14]

            Oops, Sorry, an important mistake. I should have

mentioned that while upper side of the loop consists on
quite homogeneous nerve “wires� the lower side is made
from very heterogeneous physical cause-effect chains. So
for example there is an important difference between
perception branch and side effects branches. Earlier is
a copy of the signal in the loop but latter is probably
not similar with the output.

        It's not an important mistake. I don't think it was a

mistake at all to ignore the physical mechanism when one is
trying to understand function. The mechanism is relevant
when you want to look at specific control loops, but not
when you are talking about properties of control loops in
general.

        Here's a "Rube Goldberg" control loop -- Heath Robinson, for

UK readers. Both of them dreamed up ridiculously complicated
(and funny) mechanisms for performing very simple tasks.

        <RubeGoldbergController.jpg>



        This loop controls the angle of the scale arm. A pointer arm

is attached at right angles to it, so the position of the
tip is equivalent to a perception of the actual angle of the
scale arm. It has a reference value that is adjustable by
moving the microswitch (left and right in the picture). When
the “Scale weight” is heavier than the “Sand” weight, the
arm angle changes, moving the pointer tip (the perception),
and the switch (comparator) turns on the “Red Light”
(beginning the output side of the control loop). Continuing
the output side, the red light is sensed by a device that
turns on a magnet that opens doors on a water-gate. The
water flow drives a water-wheel which is connected to a belt
that delivers sand. When the sand has piled up enough, it
will become heavier than the weight on the scale pan and the
microswitch will turn off the red light, stopping the
water-wheel and the flow of sand. Over time, the sand leaks
through holes in its pan, and at after a while the scale
weight will again be heavier than the sand pan. Â

        The required asymmetry between input (perceptual) side and

output (action side) appears here. It doesn’t matter whether
you consider the environment to include the water gate and
sand belt, or whether you consider them to be internal parts
of the controller. They are part of the environmental
feedback path from the comparator to the CEV. You could take
the shining of the red light to be the actual output, or the
opening of the water gate, or the delivery of the sand. It
doesn’t matter to the loop function. In the usual hierarchy,
very little energy is expended in passing reference values
from higher to lower levels down the output side, The main
energy use comes from the muscles and the machinery in the
environment. That’s where the power gain in the loop occurs,
no matter what values are passed between the levels.

        The CEV is the angle of the scale arm. When the CEV changes,

it provides very little energy to move the scale pointer tip
(perception) relative to the microswitch location
(comparator). In contrast, it takes quite a lot of energy to
move the water doors and to move the sand (output stages).
This controller is what is sometimes called a “bang-bang”
controller, like a thermostat, because the comparator
function has only two values “too heavy” or “too light”, so
you can’t measure numerical gains round the loop, but the
principles are the same. The controller even has an leaky
integrator output stage.

        The point of this Rube Goldberg device is to illustrate the

independence of the control concept from the physical
manifestation of its functional components. It doesn’t
incorporate your effects on higher-level perceptions and
other parts of the external environment, but it does show
the important thing. If the scale pointer needed a lot of
energy to move it when the sand had mostly leaked away, the
loop would not function well. It works best when the pointer
is very delicate and the microswitch needs only a
feather-touch to switch it on. But it also works best when
the water moves the wheel powerfully, delivering sand fast,
and when the sand also leaks fast but not as fast as it is
delivered (the asymptotic “gain” of a leaky integrator is
the ratio of the gain rate and the leak rate of the
integrator).

        Martin

Good weekend!

Eetu
(Lähetetty kännykästä / Sent from mobile)

              Eetu Pikkarainen <eetu.pikkarainen@oulu.fi                  >

kirjoitti 13.10.2017 kello 22.03:

                      [Eetu

Pikkarainen  2017-10-13 2]

Â

                    Wow Martin, that
                      [Martin Taylor

2017.10.10.13.31] was really impressive. I
quote it wholly before my new text. I change
again the title.

                      MT:                             Your mention of

varying the reference value, whereas we have
been talking about conditions in which only
the disturbance changes, brings up another
way to think of overt and masked causality.
The
masked causality is the ring of causal
connections the together form the loop, which
is masked because he feedback tends to bring
the whole ring back toward the state it was in
before the external event (disturbance or
reference change). The overt causality is that
between the reference value and the value of
the CEV in the environment. A change in
reference value changes the value of the CEV,
mediated by the ring’s masked causality. The
clearer the overt causality, which is the way
the controller “imposes its will on the
universe”, the more strongly masked is the
ring set of causal connections.

                    MT:                             If you look simply at a

canonical loop diagram, the relation between
the reference and the CEV is symmetric with
the relation between the disturbance and the
perception.
So why
does there seem to be an overt causality
between reference and CEV, whereas the causal
relation between disturbance and perception is
masked and not obvious? (If it were obvious,
this discussion would never have existed and
the long-running “Rick against the unseeing
world” saga would not have this chapter – in
which Bill P was part of “the unseeing world”
who insist that normal causality operates
throughout the control of perception).

                    MT:                             The canonical diagram

may look symmetrical, but it isn’t.
The
gain on the output side is, and must be, much
greater than that on the input (perceptual)
side. Both dynamically and in the asymptotic
equilibrium state that difference is the only
reason why the reference-to-CEV causality is
more obvious than the
disturbance-to-perception causality. As Bruce
Abbott has pointed out, the causal effect of a
step change in the disturbance is fully
apparent at the perception until at least one
loop transport delay later, and remains partly
effective for an appreciable time thereafter,
forever if the output function is a leaky
integrator.

                    MT:                             The idea of causality is

itself a gross simplification of the very
high-dimensional flow of state through an
unimaginably large Universe, but so long as
we use the word as a linguistic convenience,
we might as well try to use it somewhat
consistently. In particular, so long as
we are working on time and distance scales
where relativistic effects are trivially
small, then if A occurs before B we should not
say B causes A. Nor should we ever say that A
is the only cause of B without
specifying other conditions that surround the
two events.

Â

                      EP (from

now on): I started to think about that
symmetry / asymmetry question which has
intrigued me also earlier. To make it more
clear is draw this funny symmetric diagram
which can turned around if you wish:

Â

<image003.png>

Â

                      This is

not very adequate and perfect diagram because
the wire labels and functions are not
differentiated. The boxes are rather just
points in the diagram. (Label “C� has vanished
in conversion.) I try next describe what I
mean with these points by starting randomly
from A and assuming that subject is above and
environment below the vague blue line.

Â

                      A: Here is

the perceptual function which converts some
environmental effect (stimulus, irritation) to
a perceptual nervous signal which is then sent
forward via probably many nerves. The
individual nerves can carry different signals
but they have an average strength which
depends (among others) on the strength of the
original effect. The signal branches to B and
C.

Â

                      B: If the

controller is an elementary control unit then
the perceptual signal is sent at least to some
other units above it in the control hierarchy.
If the controller is a highest unit in the
hierarchy or the diagram depicts the whole
subject as one control system then this branch
is probably missing.

Â

                      C: (Empty

box in the picture.) This is the comparator
function where the perceptual and reference
signals are compared and the error signal
produced as a difference (remainder) between
perceptual and reference signals.

Â

                      D: This

box refers to some other control units which
are higher in the hierarchy. They send their
output as reference signals to C. The signals
they send can have combined effects and in the
case of internal conflict they can more or
less cancel each other (see Powers: MSB
p.74-).

Â

                      E: Here is

the output function which is a kind of an
amplifier. It converts the error signal to
some kind of environmental force as an output.
The strength of the output depends on the
strength of the error but is amplified or
gained(?). It can typically also realize a
time integration so that the force of the
output grows from zero (or earlier output
level) gradually and continues growing as long
as the error remains.

Â

                      F: This is

usually called the environmental feedback
function. I understand that it means the
environmental causal chain through which the
effects of the output is mediated forward
inside the loop. I guess the nature of this
chain can increase or decrease the loop gain
so that certain kind of chain can enable
stronger consequences with less output. For
example tools can be such mediators, or
feedback links.

Â

                      G: This

box refers to (immediate) side-effects of the
output. In a way these immediate side-effects
lessen the efficacy of the output as a wasted
energy. But there are also mediated
side-effects: the output changes the
situations in the environment and thus the
conditions of many (all?) environmental
processes will change which can more or less
turn the course of those processes away from
what they had been if that output had not
happened. (“Everything affects everything.�)

Â

                      H: This is

the CEV or the complex environmental variable
which (presumably) corresponds to (and is
responsible for) the environmental effect
which is converted to perceptual signal in A.
This variable is a (possibly complex) feature
of one object or of a complex of objects. The
feedback chain consists of objects whose
certain properties make them interact together
and thus form the links of the chain and CEV
is one of these links.

Â

                      I: Here

are the incoming branches of the feedback
chain and they together form the disturbance.
The value of CEV is determined by the combined
effects of all these branches and the output.
Here like with references these disturbance
effects can strengthen or weaken each other.
They typically are thought to be opposite to
the output but some effects can also be
concurrent and thus strengthen the effect of
output to the CEV.

Â

                      J: This is

not usually drawn in PCT diagrams. This is the
end of the feedback chain which happens to be
after the CEV. For example these links could
be something like newspaper, mirror,
microscope or any other mediators or chains of
mediators via which the effect of the CEV
receives the controller. Sometimes there is
perhaps none. F and J could be called the
output part of the feedback chain and the
input part of the feedback chain,
respectively.

Â

                      Now if we

look at the seeming symmetry of the loop: C
and H with incoming branches are very similar,
only error is the (theoretical) sign
conversion in C. Practically this sign
conversion seems to happen more in the
environmental side. (?) A and F with outgoing
branches are very similar. The biggest
apparent difference is between E and J. For E
it is important that it amplifies the signal
strongly enough. Instead for J it is important
that it does NOT change too much and distort
the original effect of the CEV.

Â

                      This is

the formal answer to my old problem what
justifies that in the theory of action we look
at the interaction between subject and
environment from the point of view of the
subject.

Â

Â

Eetu

Â

                      Â  Please, regard all my

statements as questions,

                      Â  no matter how they are

formulated.

Â

Â

Â

[_Boris_Hartman]

Dear Eetu…

···

From: Eetu Pikkarainen [mailto:eetu.pikkarainen@oulu.fi]
Sent: Friday, October 13, 2017 9:03 PM
To: csgnet@lists.illinois.edu
Subject: A/symmetry of control (was Re: Causality (was Re: Behavioural Illusion))

[Eetu Pikkarainen 2017-10-13 2]

EP (from now on): I started to think about that symmetry / asymmetry question which has intrigued me also earlier. To make it more clear is draw this funny symmetric diagram which can turned around if you wish:

EP : This is not very adequate and perfect diagram because the wire labels and functions are not differentiated. The boxes are rather just points in the diagram. (Label “C� has vanished in conversion.) I try next describe what I mean with these points by starting randomly from A and assuming that subject is above and environment below the vague blue line.

HB : Diagram is different from Bills (LCS III) and it’s not general. It can’t serve for interpretation of all possible behaviors. ‘H’ is not in Bills’ diagram. It’s ‘H’ or ‘I’ that is affecting ‘J’. ‘J’ in Bills’ diagram represent IQ or “input quantity� as added effects of disturbances and output. And there is just “feedback function� in environment of “control unit�. I think that “IQ� is imagined.

Bill P : FEED-BACK FUNCTION : The box represents the set of physical laws, properties, arrangements, linkages, by which the action of this system feeds-back to affect its own input, the controlled variable. That’s what feed-back means : it’s an effect of a system’s output on it’s own input.

HB : The best way to test any diagram is to think of an example of behavior. If you are sunshining the sun light will fall on your skin (perceptual input) and muscles (behavior) will be used to affect input quantity (the amount of sunlight or electromagnetic waves on the input, skin). So outside is only feedback function : effects of output on input as Bill assumed and disturbances. The same is with sleeping. So with this two examples you solved the problem how organism function (and thus your diagram) for at least 10 hours a day if you are on vacation. So think of all other examples of behavior and match them to Bills’ diagram, so that you’ll fill the whole day 24/7. And I’m sure on the end you’ll be convinced that Bill was right.

PCT diagram is general. It should explain any behavior. You don’t need to invent any other diagram. So the best way to test whether PCT diagram is right or not is to test any “real� behavior through its’ control loop (LCS III) and if anybody proves any deviations, Powers ladies should be asked for changes in diagram. I have no problem in explaining any behavior through existing PCT control loop (LCS III). Why inventing new control loop in every séance ?

Best,

Boris

A: Here is the perceptual function which converts some environmental effect (stimulus, irritation) to a perceptual nervous signal which is then sent forward via probably many nerves. The individual nerves can carry different signals but they have an average strength which depends (among others) on the strength of the original effect. The signal branches to B and C.

B: If the controller is an elementary control unit then the perceptual signal is sent at least to some other units above it in the control hierarchy. If the controller is a highest unit in the hierarchy or the diagram depicts the whole subject as one control system then this branch is probably missing.

C: (Empty box in the picture.) This is the comparator function where the perceptual and reference signals are compared and the error signal produced as a difference (remainder) between perceptual and reference signals.

D: This box refers to some other control units which are higher in the hierarchy. They send their output as reference signals to C. The signals they send can have combined effects and in the case of internal conflict they can more or less cancel each other (see Powers: MSB p.74-).

E: Here is the output function which is a kind of an amplifier. It converts the error signal to some kind of environmental force as an output. The strength of the output depends on the strength of the error but is amplified or gained(?). It can typically also realize a time integration so that the force of the output grows from zero (or earlier output level) gradually and continues growing as long as the error remains.

F: This is usually called the environmental feedback function. I understand that it means the environmental causal chain through which the effects of the output is mediated forward inside the loop. I guess the nature of this chain can increase or decrease the loop gain so that certain kind of chain can enable stronger consequences with less output. For example tools can be such mediators, or feedback links.

G: This box refers to (immediate) side-effects of the output. In a way these immediate side-effects lessen the efficacy of the output as a wasted energy. But there are also mediated side-effects: the output changes the situations in the environment and thus the conditions of many (all?) environmental processes will change which can more or less turn the course of those processes away from what they had been if that output had not happened. (“Everything affects everything.�)

H: This is the CEV or the complex environmental variable which (presumably) corresponds to (and is responsible for) the environmental effect which is converted to perceptual signal in A. This variable is a (possibly complex) feature of one object or of a complex of objects. The feedback chain consists of objects whose certain properties make them interact together and thus form the links of the chain and CEV is one of these links.

I: Here are the incoming branches of the feedback chain and they together form the disturbance. The value of CEV is determined by the combined effects of all these branches and the output. Here like with references these disturbance effects can strengthen or weaken each other. They typically are thought to be opposite to the output but some effects can also be concurrent and thus strengthen the effect of output to the CEV.

J: This is not usually drawn in PCT diagrams. This is the end of the feedback chain which happens to be after the CEV. For example these links could be something like newspaper, mirror, microscope or any other mediators or chains of mediators via which the effect of the CEV receives the controller. Sometimes there is perhaps none. F and J could be called the output part of the feedback chain and the input part of the feedback chain, respectively.

Now if we look at the seeming symmetry of the loop: C and H with incoming branches are very similar, only error is the (theoretical) sign conversion in C. Practically this sign conversion seems to happen more in the environmental side. (?) A and F with outgoing branches are very similar. The biggest apparent difference is between E and J. For E it is important that it amplifies the signal strongly enough. Instead for J it is important that it does NOT change too much and distort the original effect of the CEV.

This is the formal answer to my old problem what justifies that in the theory of action we look at the interaction between subject and environment from the point of view of the subject.

Eetu

Please, regard all my statements as questions,

no matter how they are formulated.

[_Boris_Hartman]

Dear Eetu,

···

From: Eetu Pikkarainen [mailto:eetu.pikkarainen@oulu.fi]
Sent: Monday, October 16, 2017 7:52 PM
To: csgnet@lists.illinois.edu
Subject: VS: A/symmetry of control (was Re: Causality (was Re: Behavioural Illusion))

[Eetu Pikkarainen 2017-10-16]

Dear Boris,

thank you for commenting!

I really didn’t mean that diagram as any general replacement of classical Powers diagram but rather as a temporal practice to consider the symmetry / asymmetry question of the control loop.

HB : I think that even in the case you want to practice is good to test the diagram with as many real-life behaviors you can. That will give you the answer whether the diagram (theory) is right matching the reality or not.

EP : For that it worked well at least for me and perhaps it can have other uses too. I don’t think that it is in any way contradictory with the classical diagram.

HB : As I see it is. There are too many boxes in one of them.

EP : I would like to hear what kind of feed-back function there is in sleeping?

HB : Feedback in sleeping is just keeping control in organism. It’s pure effect of output on input like definition of PCT feedback function is saying. In this case Rick was right about what is happening with organisms control in sleeping.

RM (earlier) : Sleeping is a tough one but I think it is controlling done by the autonomic nervous system that has the aim of keeping some intrinsic physiological variables in genetically determined reference states.

There is no “CV� in environment when you are sleeping as in any case in PCT. As we say we need a general theory and general diagram that can explain any behavior. Sleeping is explaining at least 6-8 hours a day what people are controlling. And PCT diagram is right explanation. So it’s confirming generality of PCT diagram.

Best,

Boris

Best

Eetu

Lähettäjä: Boris Hartman [mailto:boris.hartman@masicom.net]
Lähetetty: 15. lokakuutata 2017 11:26
Vastaanottaja: csgnet@lists.illinois.edu
Aihe: RE: A/symmetry of control (was Re: Causality (was Re: Behavioural Illusion))

Dear Eetu…

From: Eetu Pikkarainen [mailto:eetu.pikkarainen@oulu.fi]
Sent: Friday, October 13, 2017 9:03 PM
To: csgnet@lists.illinois.edu
Subject: A/symmetry of control (was Re: Causality (was Re: Behavioural Illusion))

[Eetu Pikkarainen 2017-10-13 2]

EP (from now on): I started to think about that symmetry / asymmetry question which has intrigued me also earlier. To make it more clear is draw this funny symmetric diagram which can turned around if you wish:

EP : This is not very adequate and perfect diagram because the wire labels and functions are not differentiated. The boxes are rather just points in the diagram. (Label “C� has vanished in conversion.) I try next describe what I mean with these points by starting randomly from A and assuming that subject is above and environment below the vague blue line.

HB : Diagram is different from Bills (LCS III) and it’s not general. It can’t serve for interpretation of all possible behaviors. ‘H’ is not in Bills’ diagram. It’s ‘H’ or ‘I’ that is affecting ‘J’. ‘J’ in Bills’ diagram represent IQ or “input quantity� as added effects of disturbances and output. And there is just “feedback function� in environment of “control unit�. I think that “IQ� is imagined.

Bill P : FEED-BACK FUNCTION : The box represents the set of physical laws, properties, arrangements, linkages, by which the action of this system feeds-back to affect its own input, the controlled variable. That’s what feed-back means : it’s an effect of a system’s output on it’s own input.

HB : The best way to test any diagram is to think of an example of behavior. If you are sunshining the sun light will fall on your skin (perceptual input) and muscles (behavior) will be used to affect input quantity (the amount of sunlight or electromagnetic waves on the input, skin). So outside is only feedback function : effects of output on input as Bill assumed and disturbances. The same is with sleeping. So with this two examples you solved the problem how organism function (and thus your diagram) for at least 10 hours a day if you are on vacation. So think of all other examples of behavior and match them to Bills’ diagram, so that you’ll fill the whole day 24/7. And I’m sure on the end you’ll be convinced that Bill was right.

PCT diagram is general. It should explain any behavior. You don’t need to invent any other diagram. So the best way to test whether PCT diagram is right or not is to test any “real� behavior through its’ control loop (LCS III) and if anybody proves any deviations, Powers ladies should be asked for changes in diagram. I have no problem in explaining any behavior through existing PCT control loop (LCS III). Why inventing new control loop in every séance ?

Best,

Boris

A: Here is the perceptual function which converts some environmental effect (stimulus, irritation) to a perceptual nervous signal which is then sent forward via probably many nerves. The individual nerves can carry different signals but they have an average strength which depends (among others) on the strength of the original effect. The signal branches to B and C.

B: If the controller is an elementary control unit then the perceptual signal is sent at least to some other units above it in the control hierarchy. If the controller is a highest unit in the hierarchy or the diagram depicts the whole subject as one control system then this branch is probably missing.

C: (Empty box in the picture.) This is the comparator function where the perceptual and reference signals are compared and the error signal produced as a difference (remainder) between perceptual and reference signals.

D: This box refers to some other control units which are higher in the hierarchy. They send their output as reference signals to C. The signals they send can have combined effects and in the case of internal conflict they can more or less cancel each other (see Powers: MSB p.74-).

E: Here is the output function which is a kind of an amplifier. It converts the error signal to some kind of environmental force as an output. The strength of the output depends on the strength of the error but is amplified or gained(?). It can typically also realize a time integration so that the force of the output grows from zero (or earlier output level) gradually and continues growing as long as the error remains.

F: This is usually called the environmental feedback function. I understand that it means the environmental causal chain through which the effects of the output is mediated forward inside the loop. I guess the nature of this chain can increase or decrease the loop gain so that certain kind of chain can enable stronger consequences with less output. For example tools can be such mediators, or feedback links.

G: This box refers to (immediate) side-effects of the output. In a way these immediate side-effects lessen the efficacy of the output as a wasted energy. But there are also mediated side-effects: the output changes the situations in the environment and thus the conditions of many (all?) environmental processes will change which can more or less turn the course of those processes away from what they had been if that output had not happened. (“Everything affects everything.�)

H: This is the CEV or the complex environmental variable which (presumably) corresponds to (and is responsible for) the environmental effect which is converted to perceptual signal in A. This variable is a (possibly complex) feature of one object or of a complex of objects. The feedback chain consists of objects whose certain properties make them interact together and thus form the links of the chain and CEV is one of these links.

I: Here are the incoming branches of the feedback chain and they together form the disturbance. The value of CEV is determined by the combined effects of all these branches and the output. Here like with references these disturbance effects can strengthen or weaken each other. They typically are thought to be opposite to the output but some effects can also be concurrent and thus strengthen the effect of output to the CEV.

J: This is not usually drawn in PCT diagrams. This is the end of the feedback chain which happens to be after the CEV. For example these links could be something like newspaper, mirror, microscope or any other mediators or chains of mediators via which the effect of the CEV receives the controller. Sometimes there is perhaps none. F and J could be called the output part of the feedback chain and the input part of the feedback chain, respectively.

Now if we look at the seeming symmetry of the loop: C and H with incoming branches are very similar, only error is the (theoretical) sign conversion in C. Practically this sign conversion seems to happen more in the environmental side. (?) A and F with outgoing branches are very similar. The biggest apparent difference is between E and J. For E it is important that it amplifies the signal strongly enough. Instead for J it is important that it does NOT change too much and distort the original effect of the CEV.

This is the formal answer to my old problem what justifies that in the theory of action we look at the interaction between subject and environment from the point of view of the subject.

Eetu

Please, regard all my statements as questions,

no matter how they are formulated.