The senses do not guide (oh yes they do!); Topic 2: It's all perception

[From Bruce Abbott (2016.05.05.2145 EDT)]

Rick Marken (2016.05.1630)]

[From Bruce Abbott (2016.05.05.1615 EDT)]

Rick Marken (2016.05.05.0840)

BA: If I were writing a reply to Lisberger (2015), I would not challenge his (her?) use of the phrase “using visual inputs to guide movements.� It conveys the phenomenon under investigation well enough.

RM:… It looks like visual inputs guide (cause) movements but it is easy to show (using the Test for the Controlled Variable) that visual inputs are controlled by movements, not vice versa.

BA: Actually, it does. It doesn’t merely look like visually guided movements are visually guided, they actually are.

RM: If “visually” refers to “reference for perception of movement” and “movements” refers to “visual perception of movement” then I completely agree.

BA: The term “guidedâ€? implies control…visually guided movements are movements whose trajectories through space are guided by control systems that act against disturbances while moving the skeletal frame in the desired (reference) fashion.

RM: Vision doesn’t guide; it is guided.The goal of this guidance is the reference specification for what should be perceived.

BA: Draw a circle in the air with your fingertip. To the extent that you succeed, did you not guide your limbs in such a way as to trace out what you perceive as a circle?

RM: No, I varied my limbs in such a way that the result was a visual perception of finger movement that matched my reference for that perception. Vision – my perception of finger movement – was guided (controlled) by my limb movements – keeping it at my reference specification – circular movement. Vision is controlled (guided) by movements, not vice versa. Behavior (as you may have heard) is the control of perception, not output.

BA: If I pulled gently on your arm while you attempted to trace that circle, would you not have resisted those forces so as to draw the circle anyway (assuming the forces were not too sudden or strong)?

RM: You bet. This shows that the perception limb position is also a controlled perception. And it’s not the (kinesthetic) perception of limb position that guides the output forces that resist the disturbances to limb position. The perception of limb position is controlled by the force variations.

BA: Obviously, such movements are controlled.

RM: It’s perceptions that correspond to the movements that are controlled. Remember, PCT explains control from the point of view of the controlling system, not from that of the observer of that system.

BA: In this case such control might be achieved using kinesthetic input,

RM: It’s “achieved” by controlling kinesthetic inputs. To do PCT you’ve got to try to shift from a behaviorist to an empathetic perspective on behavior.

BA: but at a higher level the movements might be subject to visual guidance – visually guided movement.>

RM: My “What is Size” demo (http://www.mindreadings.com/ControlDemo/Size.html) shows that visual input does not guide movement, unless you believed that somehow the same inputs sometimes decide to guide the mouse movements in a linear pattern and at other times in a non-linear pattern. If that’s what you think is going on – that vision is guiding movements – then please explain why the visual pattern changes its mind sometimes and makes to move in a straight and then a curved line. I prefer to understand the controlling in that demo as as a person varying their movements to control the visual pattern rather than the visual pattern controlling the movements.

What you are advancing here is an argument based purely on semantics (i.e., what one understands the words to mean). I claim that the words “visual guidance of movement�  refer to the use of visual perception to guide (control) a movement toward a reference value, and you insist on claiming that they mean something else entirely. In my opinion it is this kind of argument that drives people away from PCT, and I want nothing further to do with it.

But you do raise an issue I wish to address. We frequently hear the PCT mantra, “it’s all perception.â€? While fully recognizing that perception is really all we have – that we cannot knoow reality directly – I believe nevertheless that there is a realityy out there beyond my perceptions, a reality that our perceptions give only a partial and distorted representation of. So, when I control my arm movements in what I visually perceive to be a circular motion, I believe that there is a real arm “out there,â€? and that it is moving in an approximate circle as best as I can judge from my perceptions of it. Our sensors and the perceptual systems linked to them provide a useful representation of this motion in the form of perceptual variables, useful in the sense that, by controlling them, I control with some accuracy the actual motion. Our perceptual systems have evolved under natural selection to produce such useful representations of reality; it is only because of strong correlations between physical reality and our perceptions of it that, by controlling our perceptions, we also control to a strong degree the reality behind them.

That correlation between perception and reality does sometimes break down – we are subject to illusions and delusions, affter all, and that is one reason to recognize that what is actually under our possible direct control are our perceptions of that reality. This is true even of mechanical devices. A defective thermostat that senses a temperature of 50 degrees Faherenheit  will switch on the furnace if the set point is 70, even though the actual room temperature is already 80. We control what we perceive, and what we perceive may be a rather imperfect representation of the reality beyond our senses. When my wife turns the thermostat down because “the room is hot,â€? and I want it turned back up because in my perception “the room is cold,â€? the conflict arises because we are experiencing somewhat different perceptions of  what is in reality the same actual room temperature.

Thus, the phrase “it’s all perception� should not be taken to mean that there is nothing beyond perception to be controlled. Rather, control of perception is the only means we have to control the reality to which our perceptions correspond, if and when they do. Furthermore, some individuals may perceive a reality that differs significantly from the one most of us do, as in the case of schizophrenia. They may perceive a version of reality that does not exist (e.g., hallucinations, delusions), but like all of us, it is their perceived reality that they attempt to control.

Bruce

I thought about your conversation when I got up in the middle of the night to get some water… in the dark. A blind person could also draw a circle in the air with their finger, and they have no visual perception or guide.

*barb

···

On Thu, May 5, 2016 at 7:46 PM, Bruce Abbott bbabbott@frontier.com wrote:

[From Bruce Abbott (2016.05.05.2145 EDT)]

Â

Rick Marken (2016.05.1630)]

[From Bruce Abbott (2016.05.05.1615 EDT)]Â

Rick Marken (2016.05.05.0840)

BA: If I were writing a reply to Lisberger (2015), I would not challenge his (her?) use of the phrase “using visual inputs to guide movements.â€? It conveys the phenomenon under investigation well enough.Â

RM:… It looks like visual inputs guide (cause) movements but it is easy to show (using the Test for the Controlled Variable) that visual inputs are controlled by movements, not vice versa. Â

BA: Actually, it does. It doesn’t merely look like visually guided movements are visually guided, they actually are.

RM: If  “visually” refers to “reference for perception of movement” and “movements” refers to “visual perception of movement” then I completely agree.

 BA: The term “guidedâ€? implies control…visually guided movements are movements whose trajectories through space are guided by control systems that act against disturbances while moving the skeletal frame in the desired (reference) fashion.

RM: Vision doesn’t guide; it is guided.The goal of this guidance is the reference specification for what should be perceived.

BA: Draw a circle in the air with your fingertip. To the extent that you succeed, did you not guide your limbs in such a way as to trace out what you perceive as a circle?Â

RM: No, I varied my limbs in such a way that the result was a visual perception of finger movement that matched my reference for that perception. Vision – my perception of finger movement – was guided (controlled) by my limb movements – keeping it at my reference specification – circular movement. Vision is controlled (guided) by movements, not vice versa. Behavior (as you may have heard) is the control of perception, not output.Â

BA: If I pulled gently on your arm while you attempted to trace that circle, would you not have resisted those forces so as to draw the circle anyway (assuming the forces were not too sudden or strong)?Â

RM: You bet. This shows that the perception limb position is also a controlled perception. And it’s not the (kinesthetic) perception of limb position that guides the output forces that resist the disturbances to limb position. The perception of limb position is controlled by the force variations.Â

BA: Obviously, such movements are controlled.Â

RM: It’s perceptions that correspond to the movements that are controlled. Remember, PCT explains control from the point of view of the controlling system, not from that of the observer of that system.Â

BA: In this case such control might be achieved using kinesthetic input,

RM: It’s “achieved” by controlling kinesthetic inputs. To do PCT you’ve got to try to shift from a behaviorist to an empathetic perspective on behavior.Â

BA: but at a higher level the movements might be subject to visual guidance – visually guided movement.

RM: My “What is Size” demo (http://www.mindreadings.com/ControlDemo/Size.html) shows that visual input does not guide movement, unless you believed that somehow the same inputs sometimes decide to guide the mouse movements in a linear pattern and at other times in a non-linear pattern. If that’s what you think is going on – that vision is guiding movements – then please explain why the visual pattern changes its mind sometimes and makes to move in a straight and then a curved line. I prefer to understand the controlling in that demo as as a person varying their movements to control the visual pattern rather than the visual pattern controlling the movements.Â

Â

What you are advancing here is an argument based purely on semantics (i.e., what one understands the words to mean). I claim that the words “visual guidance of movement�  refer to the use of visual perception to guide (control) a movement toward a reference value, and you insist on claiming that they mean something else entirely. In my opinion it is this kind of argument that drives people away from PCT, and I want nothing further to do with it.

Â

But you do raise an issue I wish to address. We frequently hear the PCT mantra, “it’s all perception.â€? While fully recognizing that perception is really all we have – that we cannot know reality directly – I believieve nevertheless that there is a reality out there beyond my perceptions, a reality that our perceptions give only a partial and distorted representation of. So, when I control my arm movements in what I visually perceive to be a circular motion, I believe that there is a real arm “out there,â€? and that it is moving in an approximate circle as best as I can judge from my perceptions of it. Our sensors and the perceptual systems linked to them provide a useful representation of this motion in the form of perceptual variables, useful in the sense that, by controlling them, I control with some accuracy the actual motion. Our perceptual systems have evolved under natural selection to produce such useful representations of reality; it is only because of strong correlations between physical reality and our perceptions of it that, by controlling our perceptions, we also control to a strong degree the reality behind them.

Â

That correlation between perception and reality does sometimes break down – we are subject to illusions and delusions, after all, and that is one reason to recognize that what is actually under our possible direct control are our perceptions of that reality. This is true even of mechanical devices. A defective thermostat that senses a temperature of 50 degrees Faherenheit  will switch on the furnace if the set point is 70, even though the actual room temperature is already 80. We control what we perceive, and what we perceive may be a rather imperfect representation of the reality beyond our senses. When my wife turns the thermostat down because “the room is hot,â€? and I want it turned back up because in my perception “the room is cold,â€? the conflict arises because we are experiencing somewhat different perceptions of  what is in reality the same actual room temperature.

Â

Thus, the phrase “it’s all perception� should not be taken to mean that there is nothing beyond perception to be controlled. Rather, control of perception is the only means we have to control the reality to which our perceptions correspond, if and when they do. Furthermore, some individuals may perceive a reality that differs significantly from the one most of us do, as in the case of schizophrenia. They may perceive a version of reality that does not exist (e.g., hallucinations, delusions), but like all of us, it is their perceived reality that they attempt to control.

Â

Bruce

[From Bruce Abbott (2016.05.06.1040 EDT)]

Don’t forget that we’re dealing with a hierarchical control system. In your dad’s Little Man demo, visual perceptions are used to guide his fingertip toward the target. The vision-based control systems do this by setting references for joint angles of the elbow and shoulder. Muscle tensions then vary to change the joint angles as necessary to bring them close to their dynamically changing reference values, and the fingertip moves toward the target as a result. This movement diminishes the difference between the visually determined positions of fingertip and target, bringing the difference between them to the visual reference value of zero.

Visual input can tell you whether your movements produce a circle and provide the feedback necessary to make corrections. While you are learning, you also memorize the changes in joint-angle reference levels (and their relative timing) that produces a circular motion. After that, you can draw a circle with your eyes closed.

The blind man, being deprived of the visual control system, relies on kinesthetic perceptions whose dynamically changing reference values are “played backâ€? from memory. He moves his arm in what to him “feels likeâ€? a circular motion. If blind from birth, he can learn without visual aid what drawing a circle feels like if the limbs are guided for him during the process. Then he, too, can draw a circle, using only proprioceptive feedback.Â

What the blind man can’t do (except by chance) is reach for and grab and object whose location relative to himself is unfamiliar to him. Similarly, walking in the dark, you are likely to run into objects in a room that is unfamiliar to you. To avoid those objects your movements need visual guidance.

Bruce

···

From: bara0361@gmail.com [mailto:bara0361@gmail.com]
Sent: Friday, May 6, 2016 9:12 AM
To: csgnet@lists.illinois.edu
Subject: Re: The senses do not guide (oh yes they do!); Topic 2: It’s all perception

I thought about your conversation when I got up in the middle of the night to get some water… in the dark. A blind person could also draw a circle in the air with their finger, and they have no visual perception or guide.

*barb

On Thu, May 5, 2016 at 7:46 PM, Bruce Abbott bbabbott@frontier.com wrote:

[From Bruce Abbott (2016.05.05.2145 EDT)]

Rick Marken (2016.05.1630)]

[From Bruce Abbott (2016.05.05.1615 EDT)]

Rick Marken (2016.05.05.0840)

BA: If I were writing a reply to Lisberger (2015), I would not challenge his (her?) use of the phrase “using visual inputs to guide movements.� It conveys the phenomenon under investigation well enough.

RM:… It looks like visual inputs guide (cause) movements but it is easy to show (using the Test for the Controlled Variable) that visual inputs are controlled by movements, not vice versa.

BA: Actually, it does. It doesn’t merely look like visually guided movements are visually guided, they actually are.

RM: If “visually” refers to “reference for perception of movement” and “movements” refers to “visual perception of movement” then I completely agree.

BA: The term “guidedâ€? implies control…visually guided movements are movements whose trajectories through space are guided by control systems that act against disturbances while moving the skeletal frame in the desired (reference) fashion.

RM: Vision doesn’t guide; it is guided.The goal of this guidance is the reference specification for what should be perceived.

BA: Draw a circle in the air with your fingertip. To the extent that you succeed, did you not guide your limbs in such a way as to trace out what you perceive as a circle?

RM: No, I varied my limbs in such a way that the result was a visual perception of finger movement that matched my reference for that perception. Vision – my perception of finger movement – was guided (controlled) by my limb movements – keeping it at my reference specification – circular movement. Vision is controlled (guided) by movements, not vice versa. Behavior (as you may have heard) is the control of perception, not output.

BA: If I pulled gently on your arm while you attempted to trace that circle, would you not have resisted those forces so as to draw the circle anyway (assuming the forces were not too sudden or strong)?

RM: You bet. This shows that the perception limb position is also a controlled perception. And it’s not the (kinesthetic) perception of limb position that guides the output forces that resist the disturbances to limb position. The perception of limb position is controlled by the force variations.

BA: Obviously, such movements are controlled.

RM: It’s perceptions that correspond to the movements that are controlled. Remember, PCT explains control from the point of view of the controlling system, not from that of the observer of that system.

BA: In this case such control might be achieved using kinesthetic input,

RM: It’s “achieved” by controlling kinesthetic inputs. To do PCT you’ve got to try to shift from a behaviorist to an empathetic perspective on behavior.

BA: but at a higher level the movements might be subject to visual guidance – visually guided movement.

/div>

RM: My “What is Size” demo (http://www.mindreadings.com/ControlDemo/Size.html) shows that visual input does not guide movement, unless you believed that somehow the same inputs sometimes decide to guide the mouse movements in a linear pattern and at other times in a non-linear pattern. If that’s what you think is going on – that vision is guiding movements – then please explain why the visual pattern changes its mind sometimes and makes to move in a straight and then a curved line. I prefer to understand the controlling in that demo as as a person varying their movements to control the visual pattern rather than the visual pattern controlling the movements.

What you are advancing here is an argument based purely on semantics (i.e., what one understands the words to mean). I claim that the words “visual guidance of movement� refer to the use of visual perception to guide (control) a movement toward a reference value, and you insist on claiming that they mean something else entirely. In my opinion it is this kind of argument that drives people away from PCT, and I want nothing further to do with it.

But you do raise an issue I wish to address. We frequently hear the PCT mantra, “it’s all perception.â€? While fully recognizing that perception is really all we have – that we cannot know reality directtly – I believe nevertheless that there is a reality out there beyonnd my perceptions, a reality that our perceptions give only a partial and distorted representation of. So, when I control my arm movements in what I visually perceive to be a circular motion, I believe that there is a real arm “out there,â€? and that it is moving in an approximate circle as best as I can judge from my perceptions of it. Our sensors and the perceptual systems linked to them provide a useful representation of this motion in the form of perceptual variables, useful in the sense that, by controlling them, I control with some accuracy the actual motion. Our perceptual systems have evolved under natural selection to produce such useful representations of reality; it is only because of strong correlations between physical reality and our perceptions of it that, by controlling our perceptions, we also control to a strong degree the reality behind them.

That correlation between perception and reality does sometimes break down – we are subject tto illusions and delusions, after all, and that is one reason to recognize that what is actually under our possible direct control are our perceptions of that reality. This is true even of mechanical devices. A defective thermostat that senses a temperature of 50 degrees Faherenheit will switch on the furnace if the set point is 70, even though the actual room temperature is already 80. We control what we perceive, and what we perceive may be a rather imperfect representation of the reality beyond our senses. When my wife turns the thermostat down because “the room is hot,â€? and I want it turned back up because in my perception “the room is cold,â€? the conflict arises because we are experiencing somewhat different perceptions of what is in reality the same actual room temperature.

Thus, the phrase “it’s all perception� should not be taken to mean that there is nothing beyond perception to be controlled. Rather, control of perception is the only means we have to control the reality to which our perceptions correspond, if and when they do. Furthermore, some individuals may perceive a reality that differs significantly from the one most of us do, as in the case of schizophrenia. They may perceive a version of reality that does not exist (e.g., hallucinations, delusions), but like all of us, it is their perceived reality that they attempt to control.

Bruce

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7596 / Virus Database: 4565/12174 - Release Date: 05/06/16

I “see” what you are saying. I understand that in a vision-based demo, vision would be necessary to complete the task, as there is no other way to perceive what is on that computer screen.Â

At the same time that we are perceiving by seeing, we are also observers of our own actions. At some point, it seems to me, we move from receiving the perception to watching what happens next, then perceiving if there is an error, then watching the result again, etc.

If you were to look away for a moment while you’re drawing that circle in the air, you’d probably finish drawing it fairly well. The visual aspect is not necessary to the drawing of the circle. So vision would be necessary to know whether you made a decent circle, but it doesn’t appear to me to control how or whether a circle is made.

···

On Fri, May 6, 2016 at 8:39 AM, Bruce Abbott bbabbott@frontier.com wrote:

[From Bruce Abbott (2016.05.06.1040 EDT)]

Â

Don’t forget that we’re dealing with a hierarchical control system. In your dad’s Little Man demo, visual perceptions are used to guide his fingertip toward the target. The vision-based control systems do this by setting references for joint angles of the elbow and shoulder. Muscle tensions then vary to change the joint angles as necessary to bring them close to their dynamically changing reference values, and the fingertip moves toward the target as a result. This movement diminishes the difference between the visually determined positions of fingertip and target, bringing the difference between them to the visual reference value of zero.

Â

Visual input can tell you whether your movements produce a circle and provide the feedback necessary to make corrections. While you are learning, you also memorize the changes in joint-angle reference levels (and their relative timing) that produces a circular motion. After that, you can draw a circle with your eyes closed.

Â

The blind man, being deprived of the visual control system, relies on kinesthetic perceptions whose dynamically changing reference values are “played backâ€? from memory. He moves his arm in what to him “feels likeâ€? a circular motion. If blind from birth, he can learn without visual aid what drawing a circle feels like if the limbs are guided for him during the process. Then he, too, can draw a circle, using only proprioceptive feedback.Â

Â

What the blind man can’t do (except by chance) is reach for and grab and object whose location relative to himself is unfamiliar to him. Similarly, walking in the dark, you are likely to run into objects in a room that is unfamiliar to you. To avoid those objects your movements need visual guidance.

Â

Bruce

Â

From: bara0361@gmail.com [mailto:bara0361@gmail.com]
Sent: Friday, May 6, 2016 9:12 AM
To: csgnet@lists.illinois.edu
Subject: Re: The senses do not guide (oh yes they do!); Topic 2: It’s all perception

Â

I thought about your conversation when I got up in the middle of the night to get some water… in the dark. A blind person could also draw a circle in the air with their finger, and they have no visual perception or guide.

Â

*barb

Â

On Thu, May 5, 2016 at 7:46 PM, Bruce Abbott bbabbott@frontier.com wrote:

[From Bruce Abbott (2016.05.05.2145 EDT)]

Â

Rick Marken (2016.05.1630)]

[From Bruce Abbott (2016.05.05.1615 EDT)]Â

Rick Marken (2016.05.05.0840)

BA: If I were writing a reply to Lisberger (2015), I would not challenge his (her?) use of the phrase “using visual inputs to guide movements.â€? It conveys the phenomenon under investigation well enough.Â

RM:… It looks like visual inputs guide (cause) movements but it is easy to show (using the Test for the Controlled Variable) that visual inputs are controlled by movements, not vice versa. Â

BA: Actually, it does. It doesn’t merely look like visually guided movements are visually guided, they actually are.

RM: If  “visually” refers to “reference for perception of movement” and “movements” refers to “visual perception of movement” then I completely agree.

 BA: The term “guidedâ€? implies control…visually guided movements are movements whose trajectories through space are guided by control systems that act against disturbances while moving the skeletal frame in the desired (reference) fashion.

RM: Vision doesn’t guide; it is guided.The goal of this guidance is the reference specification for what should be perceived.

BA: Draw a circle in the air with your fingertip. To the extent that you succeed, did you not guide your limbs in such a way as to trace out what you perceive as a circle?Â

RM: No, I varied my limbs in such a way that the result was a visual perception of finger movement that matched my reference for that perception. Vision – my perception of finger movement – was guided (controlled) by my limb movements – keeping it at my reference specification – circular movement. Vision is controlled (guided) by movements, not vice versa. Behavior (as you may have heard) is the control of perception, not output.Â

BA: If I pulled gently on your arm while you attempted to trace that circle, would you not have resisted those forces so as to draw the circle anyway (assuming the forces were not too sudden or strong)?Â

RM: You bet. This shows that the perception limb position is also a controlled perception. And it’s not the (kinesthetic) perception of limb position that guides the output forces that resist the disturbances to limb position. The perception of limb position is controlled by the force variations.Â

BA: Obviously, such movements are controlled.Â

RM: It’s perceptions that correspond to the movements that are controlled. Remember, PCT explains control from the point of view of the controlling system, not from that of the observer of that system.Â

BA: In this case such control might be achieved using kinesthetic input,

RM: It’s “achieved” by controlling kinesthetic inputs. To do PCT you’ve got to try to shift from a behaviorist to an empathetic perspective on behavior.Â

BA: but at a higher level the movements might be subject to visual guidance – visually guided moveement.

RM: My “What is Size” demo (http://www.mindreadings.com/ControlDemo/Size.html) shows that visual input does not guide movement, unless you believed that somehow the same inputs sometimes decide to guide the mouse movements in a linear pattern and at other times in a non-linear pattern. If that’s what you think is going on – that vision is guiding movements – then please explain why the visual pattern changes its mind sometimes and makes to move in a straight and then a curved line. I prefer to understand the controlling in that demo as as a person varying their movements to control the visual pattern rather than the visual pattern controlling the movements.Â

Â

What you are advancing here is an argument based purely on semantics (i.e., what one understands the words to mean). I claim that the words “visual guidance of movement�  refer to the use of visual perception to guide (control) a movement toward a reference value, and you insist on claiming that they mean something else entirely. In my opinion it is this kind of argument that drives people away from PCT, and I want nothing further to do with it.

Â

But you do raise an issue I wish to address. We frequently hear the PCT mantra, “it’s all perception.â€? While fully recognizing that perception is really all we have – that we cannot know reality directly – I believe nevertheless tthat there is a reality out there beyond my perceptions, a reality that our perceptions give only a partial and distorted representation of. So, when I control my arm movements in what I visually perceive to be a circular motion, I believe that there is a real arm “out there,â€? and that it is moving in an approximate circle as best as I can judge from my perceptions of it. Our sensors and the perceptual systems linked to them provide a useful representation of this motion in the form of perceptual variables, useful in the sense that, by controlling them, I control with some accuracy the actual motion. Our perceptual systems have evolved under natural selection to produce such useful representations of reality; it is only because of strong correlations between physical reality and our perceptions of it that, by controlling our perceptions, we also control to a strong degree the reality behind them.

Â

That correlation between perception and reality does sometimes break down – we are subject to illusions and delusions, after all, and that is one reason to recognize that what is actually under our possible direct control are our perceptions of that reality. This is true even of mechanical devices. A defective thermostat that senses a temperature of 50 degrees Faherenheit  will switch on the furnace if the set point is 70, even though the actual room temperature is already 80. We control what we perceive, and what we perceive may be a rather imperfect representation of the reality beyond our senses. When my wife turns the thermostat down because “the room is hot,� and I want it turned back up because in my perception “the room is cold,� the conflict arises because we are experiencing somewhat different perceptions of  what is in reality the same actual room temperature.

Â

Thus, the phrase “it’s all perception� should not be taken to mean that there is nothing beyond perception to be controlled. Rather, control of perception is the only means we have to control the reality to which our perceptions correspond, if and when they do. Furthermore, some individuals may perceive a reality that differs significantly from the one most of us do, as in the case of schizophrenia. They may perceive a version of reality that does not exist (e.g., hallucinations, delusions), but like all of us, it is their perceived reality that they attempt to control.

Â

Bruce

Â

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7596 / Virus Database: 4565/12174 - Release Date: 05/06/16

[From Bruce Abbott (2016.05.06.1125 EDT)]

I agree with you entirely, except to note that perceiving and acting usually occur simultaneously and continuously in an active control loop, rather than sequentially. There are exceptions, of course. For example, if one were aiming a cannon, one would aim, fire, then note where the cannonball struck, then re-aim, fire again, etc., in order to home in on the target. Many ordinary tasks are accomplished in the same way.

Bruce

···

From: bara0361@gmail.com [mailto:bara0361@gmail.com]
Sent: Friday, May 6, 2016 10:56 AM
To: csgnet@lists.illinois.edu
Subject: Re: The senses do not guide (oh yes they do!); Topic 2: It’s all perception

I “see” what you are saying. I understand that in a vision-based demo, vision would be necessary to complete the task, as there is no other way to perceive what is on that computer screen.

At the same time that we are perceiving by seeing, we are also observers of our own actions. At some point, it seems to me, we move from receiving the perception to watching what happens next, then perceiving if there is an error, then watching the result again, etc.

If you were to look away for a moment while you’re drawing that circle in the air, you’d probably finish drawing it fairly well. The visual aspect is not necessary to the drawing of the circle. So vision would be necessary to know whether you made a decent circle, but it doesn’t appear to me to control how or whether a circle is made.

On Fri, May 6, 2016 at 8:39 AM, Bruce Abbott bbabbott@frontier.com wrote:

[From Bruce Abbott (2016.05.06.1040 EDT)]

Don’t forget that we’re dealing with a hierarchical control system. In your dad’s Little Man demo, visual perceptions are used to guide his fingertip toward the target. The vision-based control systems do this by setting references for joint angles of the elbow and shoulder. Muscle tensions then vary to change the joint angles as necessary to bring them close to their dynamically changing reference values, and the fingertip moves toward the target as a result. This movement diminishes the difference between the visually determined positions of fingertip and target, bringing the difference between them to the visual reference value of zero.

Visual input can tell you whether your movements produce a circle and provide the feedback necessary to make corrections. While you are learning, you also memorize the changes in joint-angle reference levels (and their relative timing) that produces a circular motion. After that, you can draw a circle with your eyes closed.

The blind man, being deprived of the visual control system, relies on kinesthetic perceptions whose dynamically changing reference values are “played back� from memory. He moves his arm in what to him “feels like� a circular motion. If blind from birth, he can learn without visual aid what drawing a circle feels like if the limbs are guided for him during the process. Then he, too, can draw a circle, using only proprioceptive feedback.

What the blind man can’t do (except by chance) is reach for and grab and object whose location relative to himself is unfamiliar to him. Similarly, walking in the dark, you are likely to run into objects in a room that is unfamiliar to you. To avoid those objects your movements need visual guidance.

Bruce

From: bara0361@gmail.com [mailto:bara0361@gmail.com]
Sent: Friday, May 6, 2016 9:12 AM
To: csgnet@lists.illinois.edu
Subject: Re: The senses do not guide (oh yes they do!); Topic 2: It’s all perception

I thought about your conversation when I got up in the middle of the night to get some water… in the dark. A blind person could also draw a circle in the air with their finger, and they have no visual perception or guide.

*barb

On Thu, May 5, 2016 at 7:46 PM, Bruce Abbott bbabbott@frontier.com wrote:

[From Bruce Abbott (2016.05.05.2145 EDT)]

Rick Marken (2016.05.1630)]

[From Bruce Abbott (2016.05.05.1615 EDT)]

Rick Marken (2016.05.05.0840)

BA: If I were writing a reply to Lisberger (2015), I would not challenge his (her?) use of the phrase “using visual inputs to guide movements.� It conveys the phenomenon under investigation well enough.

RM:… It looks like visual inputs guide (cause) movements but it is easy to show (using the Test for the Controlled Variable) that visual inputs are controlled by movements, not vice versa.

BA: Actually, it does. It doesn’t merely look like visually guided movements are visually guided, they actually are.

RM: If “visually” refers to “reference for perception of movement” and “movements” refers to “visual perception of movement” then I completely agree.

BA: The term “guidedâ€? implies control…visually guided movements are movements whose trajectories through space are guided by control systems that act against disturbances while moving the skeletal frame in the desired (reference) fashion.

RM: Vision doesn’t guide; it is guided.The goal of this guidance is the reference specification for what should be perceived.

BA: Draw a circle in the air with your fingertip. To the extent that you succeed, did you not guide your limbs in such a way as to trace out what you perceive as a circle?

RM: No, I varied my limbs in such a way that the result was a visual perception of finger movement that matched my reference for that perception. Vision – my perception of finger movement – was guided (controlled) by my limb movements – keeping it at my reference specification – circular movement. Vision is controlled (guided) by movements, not vice versa. Behavior (as you may have heard) is the control of perception, not output.

BA: If I pulled gently on your arm while you attempted to trace that circle, would you not have resisted those forces so as to draw the circle anyway (assuming the forces were not too sudden or strong)?

RM: You bet. This shows that the perception limb position is also a controlled perception. And it’s not the (kinesthetic) perception of limb position that guides the output forces that resist the disturbances to limb position. The perception of limb position is controlled by the force variations.

BA: Obviously, such movements are controlled.

RM: It’s perceptions that correspond to the movements that are controlled. Remember, PCT explains control from the point of view of the controlling system, not from that of the observer of that system.

BA: In this case such control might be achieved using kinesthetic input,

RM: It’s “achieved” by controlling kinesthetic inputs. To do PCT you’ve got to try to shift from a behaviorist to an empathetic perspective on behavior.

BA: but at a higher level the movements might be subject to visual guidance – visually guided movement.<

RM: My “What is Size” demo (http://www.mindreadings.com/ControlDemo/Size.html) shows that visual input does not guide movement, unless you believed that somehow the same inputs sometimes decide to guide the mouse movements in a linear pattern and at other times in a non-linear pattern. If that’s what you think is going on – that vision is guiding movements – then please explain why the visual pattern changes its mind sometimes and makes to move in a straight and then a curved line. I prefer to understand the controlling in that demo as as a person varying their movements to control the visual pattern rather than the visual pattern controlling the movements.

What you are advancing here is an argument based purely on semantics (i.e., what one understands the words to mean). I claim that the words “visual guidance of movement� refer to the use of visual perception to guide (control) a movement toward a reference value, and you insist on claiming that they mean something else entirely. In my opinion it is this kind of argument that drives people away from PCT, and I want nothing further to do with it.

But you do raise an issue I wish to address. We frequently hear the PCT mantra, “it’s all perception.â€? While fully recognizing that perception is really all we have – that we cannot know reality directly – I believe nevertheless that there iss a reality out there beyond my perceptions, a reality that our perceptions give only a partial and distorted representation of. So, when I control my arm movements in what I visually perceive to be a circular motion, I believe that there is a real arm “out there,â€? and that it is moving in an approximate circle as best as I can judge from my perceptions of it. Our sensors and the perceptual systems linked to them provide a useful representation of this motion in the form of perceptual variables, useful in the sense that, by controlling them, I control with some accuracy the actual motion. Our perceptual systems have evolved under natural selection to produce such useful representations of reality; it is only because of strong correlations between physical reality and our perceptions of it that, by controlling our perceptions, we also control to a strong degree the reality behind them.

That correlation between perception and reality does sometimes break down – we are subject to illusions and delusions, after all, and that iss one reason to recognize that what is actually under our possible direct control are our perceptions of that reality. This is true even of mechanical devices. A defective thermostat that senses a temperature of 50 degrees Faherenheit will switch on the furnace if the set point is 70, even though the actual room temperature is already 80. We control what we perceive, and what we perceive may be a rather imperfect representation of the reality beyond our senses. When my wife turns the thermostat down because “the room is hot,â€? and I want it turned back up because in my perception “the room is cold,â€? the conflict arises because we are experiencing somewhat different perceptions of what is in reality the same actual room temperature.

Thus, the phrase “it’s all perception� should not be taken to mean that there is nothing beyond perception to be controlled. Rather, control of perception is the only means we have to control the reality to which our perceptions correspond, if and when they do. Furthermore, some individuals may perceive a reality that differs significantly from the one most of us do, as in the case of schizophrenia. They may perceive a version of reality that does not exist (e.g., hallucinations, delusions), but like all of us, it is their perceived reality that they attempt to control.

Bruce

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Yep, agreed!
*barb

···

On Fri, May 6, 2016 at 9:26 AM, Bruce Abbott bbabbott@frontier.com wrote:

[From Bruce Abbott (2016.05.06.1125 EDT)]

Â

I agree with you entirely, except to note that perceiving and acting usually occur simultaneously and continuously in an active control loop, rather than sequentially. There are exceptions, of course. For example, if one were aiming a cannon, one would aim, fire, then note where the cannonball struck, then re-aim, fire again, etc., in order to home in on the target. Many ordinary tasks are accomplished in the same way.

Â

Bruce

Â

From: bara0361@gmail.com [mailto:bara0361@gmail.com]
Sent: Friday, May 6, 2016 10:56 AM

To: csgnet@lists.illinois.edu
Subject: Re: The senses do not guide (oh yes they do!); Topic 2: It’s all perception

Â

I “see” what you are saying. I understand that in a vision-based demo, vision would be necessary to complete the task, as there is no other way to perceive what is on that computer screen.Â

Â

At the same time that we are perceiving by seeing, we are also observers of our own actions. At some point, it seems to me, we move from receiving the perception to watching what happens next, then perceiving if there is an error, then watching the result again, etc.

Â

If you were to look away for a moment while you’re drawing that circle in the air, you’d probably finish drawing it fairly well. The visual aspect is not necessary to the drawing of the circle. So vision would be necessary to know whether you made a decent circle, but it doesn’t appear to me to control how or whether a circle is made.

Â

Â

Â

On Fri, May 6, 2016 at 8:39 AM, Bruce Abbott bbabbott@frontier.com wrote:

[From Bruce Abbott (2016.05.06.1040 EDT)]

Â

Don’t forget that we’re dealing with a hierarchical control system. In your dad’s Little Man demo, visual perceptions are used to guide his fingertip toward the target. The vision-based control systems do this by setting references for joint angles of the elbow and shoulder. Muscle tensions then vary to change the joint angles as necessary to bring them close to their dynamically changing reference values, and the fingertip moves toward the target as a result. This movement diminishes the difference between the visually determined positions of fingertip and target, bringing the difference between them to the visual reference value of zero.

Â

Visual input can tell you whether your movements produce a circle and provide the feedback necessary to make corrections. While you are learning, you also memorize the changes in joint-angle reference levels (and their relative timing) that produces a circular motion. After that, you can draw a circle with your eyes closed.

Â

The blind man, being deprived of the visual control system, relies on kinesthetic perceptions whose dynamically changing reference values are “played backâ€? from memory. He moves his arm in what to him “feels likeâ€? a circular motion. If blind from birth, he can learn without visual aid what drawing a circle feels like if the limbs are guided for him during the process. Then he, too, can draw a circle, using only proprioceptive feedback.Â

Â

What the blind man can’t do (except by chance) is reach for and grab and object whose location relative to himself is unfamiliar to him. Similarly, walking in the dark, you are likely to run into objects in a room that is unfamiliar to you. To avoid those objects your movements need visual guidance.

Â

Bruce

Â

From: bara0361@gmail.com [mailto:bara0361@gmail.com]
Sent: Friday, May 6, 2016 9:12 AM
To: csgnet@lists.illinois.edu
Subject: Re: The senses do not guide (oh yes they do!); Topic 2: It’s all perception

Â

I thought about your conversation when I got up in the middle of the night to get some water… in the dark. A blind person could also draw a circle in the air with their finger, and they have no visual perception or guide.

Â

*barb

Â

On Thu, May 5, 2016 at 7:46 PM, Bruce Abbott bbabbott@frontier.com wrote:

[From Bruce Abbott (2016.05.05.2145 EDT)]

Â

Rick Marken (2016.05.1630)]

[From Bruce Abbott (2016.05.05.1615 EDT)]Â

Rick Marken (2016.05.05.0840)

BA: If I were writing a reply to Lisberger (2015), I would not challenge his (her?) use of the phrase “using visual inputs to guide movements.â€? It conveys the phenomenon under investigation well enough.Â

RM:… It looks like visual inputs guide (cause) movements but it is easy to show (using the Test for the Controlled Variable) that visual inputs are controlled by movements, not vice versa. Â

BA: Actually, it does. It doesn’t merely look like visually guided movements are visually guided, they actually are.

RM: If  “visually” refers to “reference for perception of movement” and “movements” refers to “visual perception of movement” then I completely agree.

 BA: The term “guidedâ€? implies control…visually guided movements are movements whose trajectories through space are guided by control systems that act against disturbances while moving the skeletal frame in the desired (reference) fashion.

RM: Vision doesn’t guide; it is guided.The goal of this guidance is the reference specification for what should be perceived.

BA: Draw a circle in the air with your fingertip. To the extent that you succeed, did you not guide your limbs in such a way as to trace out what you perceive as a circle?Â

RM: No, I varied my limbs in such a way that the result was a visual perception of finger movement that matched my reference for that perception. Vision – my perception of finger movement – was guided (controlled) by my limb movements – keeping it at my reference specification – circular movement. Vision is controlled (guided) by movements, not vice versa. Behavior (as you may have heard) is the control of perception, not output.Â

BA: If I pulled gently on your arm while you attempted to trace that circle, would you not have resisted those forces so as to draw the circle anyway (assuming the forces were not too sudden or strong)?Â

RM: You bet. This shows that the perception limb position is also a controlled perception. And it’s not the (kinesthetic) perception of limb position that guides the output forces that resist the disturbances to limb position. The perception of limb position is controlled by the force variations.Â

BA: Obviously, such movements are controlled.Â

RM: It’s perceptions that correspond to the movements that are controlled. Remember, PCT explains control from the point of view of the controlling system, not from that of the observer of that system.Â

BA: In this case such control might be achieved using kinesthetic input,

RM: It’s “achieved” by controlling kinesthetic inputs. To do PCT you’ve got to try to shift from a behaviorist to an empathetic perspective on behavior.Â

BA: but at a higher level the movements might be subject to visual guidance – visually guided movement.

<

RM: My “What is Size” demo (http://www.mindreadings.com/ControlDemo/Size.html) shows that visual input does not guide movement, unless you believed that somehow the same inputs sometimes decide to guide the mouse movements in a linear pattern and at other times in a non-linear pattern. If that’s what you think is going on – that vision is guiding movements – then please explain why the visual pattern changes its mind sometimes and makes to move in a straight and then a curved line. I prefer to understand the controlling in that demo as as a person varying their movements to control the visual pattern rather than the visual pattern controlling the movements.Â

Â

What you are advancing here is an argument based purely on semantics (i.e., what one understands the words to mean). I claim that the words “visual guidance of movement�  refer to the use of visual perception to guide (control) a movement toward a reference value, and you insist on claiming that they mean something else entirely. In my opinion it is this kind of argument that drives people away from PCT, and I want nothing further to do with it.

Â

But you do raise an issue I wish to address. We frequently hear the PCT mantra, “it’s all perception.â€? While fully recognizing that perception is really all we have – that we cannot know reality directly – €“ I believe nevertheless that there is a reality out there beyond my perceptions, a reality that our perceptions give only a partial and distorted representation of. So, when I control my arm movements in what I visually perceive to be a circular motion, I believe that there is a real arm “out there,â€? and that it is moving in an approximate circle as best as I can judge from my perceptions of it. Our sensors and the perceptual systems linked to them provide a useful representation of this motion in the form of perceptual variables, useful in the sense that, by controlling them, I control with some accuracy the actual motion. Our perceptual systems have evolved under natural selection to produce such useful representations of reality; it is only because of strong correlations between physical reality and our perceptions of it that, by controlling our perceptions, we also control to a strong degree the reality behind them.

Â

That correlation between perception and reality does sometimes break down – we are subject to illusions and delusions, aftter all, and that is one reason to recognize that what is actually under our possible direct control are our perceptions of that reality. This is true even of mechanical devices. A defective thermostat that senses a temperature of 50 degrees Faherenheit  will switch on the furnace if the set point is 70, even though the actual room temperature is already 80. We control what we perceive, and what we perceive may be a rather imperfect representation of the reality beyond our senses. When my wife turns the thermostat down because “the room is hot,â€? and I want it turned back up because in my perception “the room is cold,â€? the conflict arises because we are experiencing somewhat different perceptions of  what is in reality the same actual room temperature.

Â

Thus, the phrase “it’s all perception� should not be taken to mean that there is nothing beyond perception to be controlled. Rather, control of perception is the only means we have to control the reality to which our perceptions correspond, if and when they do. Furthermore, some individuals may perceive a reality that differs significantly from the one most of us do, as in the case of schizophrenia. They may perceive a version of reality that does not exist (e.g., hallucinations, delusions), but like all of us, it is their perceived reality that they attempt to control.

Â

Bruce

Â

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Checked by AVG - www.avg.com
Version: 2016.0.7596 / Virus Database: 4565/12174 - Release Date: 05/06/16

Â

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2016.0.7596 / Virus Database: 4565/12174 - Release Date: 05/06/16

[From Rick Marken (2016.05.07.1000)]

···

Bruce Abbott (2016.05.05.2145 EDT)

Â

RM: My “What is Size” demo (http://www.mindreadings.com/ControlDemo/Size.html) shows that visual input does not guide movement…

Â

BA: What you are advancing here is an argument based purely on semantics (i.e., what one understands the words to mean).Â

RM: Yes, admit it. I try to use meaning when I say things;-)

BA: I claim that the words “visual guidance of movementâ€?  refer to the use of visual perception to guide (control) a movement toward a reference value, and you insist on claiming that they mean something else entirely.Â

RM: Really? What is the entirely different meaning that I am claiming?Â

RM: I understood you to be referring to exactly what you say you are referring to when you say “visual guidance of movement”: the use of visual perception to guide (control) movement toward a reference value. It’s the word “guide” (or control) in that statement to which I object.Â

RM: Both the dictionary and I define guide as “to direct the course of action”. So I took you to be saying that visual perception is used to direct the course of a movement. It is this meaning of the phrase “visual guidance of movement” that is wrong. In a control loop visual perception is not used to direct the movements that affect the state of that visual perception.Â

RM: This is one of the most surprising things that Powers demonstrated about the behavior of a control loop. It is demonstrated in the basic tracking task by the lack of correlation between visual perception (variations in the position of the cursor relative to the target – the controlled variable) and mouse movements that affect that perception (http://www.mindreadings.com/ControlDemo/BasicTrack.html). In my very first piece of research based on PCT I showed that there is no aspect of the visual perception that can be seen as directing the movements that affect the controlled variable (http://www.mindreadings.com/ControlDemo/Cause.html). Â

RM: The fact is that, in a closed loop, when control is good, visual perception is guided (controlled) by the movements that affect this perception, it does not guide these movements. PCT shows that the senses do not guide; rather they are guided (controlled).Â

RM:Â Besides the fact that it is factually wrong, the problem with thinking of the senses as guiding movements is that it misdirects research aimed at understanding the behavior of living control systems. It leads you to do research aimed at discovering the sensory/perceptual variables that guide (cause) Â behavior rather then the sensory/perceptual variables that are under control. In other words, the persistent belief in the “common sense” idea that sensory/perceptual variables guide movement (behavior) is the main obstacle to the development of a science of living systems based on PCT.

Â

BA: In my opinion it is this kind of argument that drives people away from PCT, and I want nothing further to do with it.

RM: I agree with you on this. My experience is that people get very upset when I have demonstrated this fact to them. It is very counter intuitive and it certainly goes against the fundamental assumptions that scientific psychologists make about behavior.Â

Â

 BA: But you do raise an issue I wish to address. We frequently hear the PCT mantra, “it’s all perception.â€? While fully recognizing that perception is really all we have – that we cannot know reality directly – I believe nevertheless that there is a reality out theree beyond my perceptions, a reality that our perceptions give only a partial and distorted representation of.Â

RM: I also agree that there is a reality out there. But I think our perceptions are representations of the aspects of that reality that we have to be able to control in order to survive. I think of perception as an adaptive representation of reality – reality being what is described by the models of physics and chemistry and eventually the life sciences – rather than as a picture of reality as seen through a glass darkly.Â

BA: So, when I control my arm movements in what I visually perceive to be a circular motion, I believe that there is a real arm “out there,â€? and that it is moving in an approximate circle as best as I can judge from my perceptions of it. Our sensors and the perceptual systems linked to them provide a useful representation of this motion in the form of perceptual variables, useful in the sense that, by controlling them, I control with some accuracy the actual motion.

RM: I pretty much agree. Though it’s really only the perceptions that matter to the behaving system; perception is reality for the behaving system.Â

Â

BA: Thus, the phrase “it’s all perceptionâ€? should not be taken to mean that there is nothing beyond perception to be controlled.Â

RM: Absolutely. PCT is not solipsism! There is an environment (reality) side of the PCT model! The phase “it’s all perception” simply describes the situation from the point of view of the behaving system. One of the main goals of PCT research is to determine what aspects (functions) of the environment – what perceptions – are controlled by the organism.

Best

Rick

Â

Rather, control of perception is the only means we have to control the reality to which our perceptions correspond, if and when they do. Furthermore, some individuals may perceive a reality that differs significantly from the one most of us do, as in the case of schizophrenia. They may perceive a version of reality that does not exist (e.g., hallucinations, delusions), but like all of us, it is their perceived reality that they attempt to control.


Richard S. MarkenÂ

Author, with Timothy A. Carey, of  Controlling People: The Paradoxical Nature of Being Human