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Wolf Kirchmeir · Guest

On Sun, 31 Aug 2003 22:50:35 GMT, Lester Zick wrote:

[quote]Well as far as this goes the idea of a programmed machine implies a
programmer of necessity I would think. A universe on the other hand
would not imply anything except itself. What we seem to have here is
some suggestion of deism.
[/quote]
All living organisms are programmed machines.

--
Best Wishes,
Wolf Kirchmeir, Blind River ON
"Not that brains are everything --
you>ll also need a skull to put them in." (Nancy Franklin, 1997)
<just one w and plain ca for correct address>

Lester Zick · Guest

On 31 Aug 2003 09:41:26 -0700, dan@oricomtech.com (dan michaels)
wrote:

[quote]Joe Legris <jalegris@xympatico.ca> wrote in message news:<3F4FF727.4080605@xympatico.ca>...

If you define a model as a simplified representation of a system then it
is not a copy by definition. End of argument.

Models in the brain are distillations of the aspects of reality that are
relevant to the organism. For example, a brain may contain a ballistic
model that allows one to predict where a thrown rock will land. The
relevant aspect of such a model is the relationship between perceived
heft of an object and it>s expected trajectory when thrown with a
particular effort. It is conceivable that the brain actually solves the
differential equation of motion using a neural network that has been
tuned over years of practice.

Much of what you say above makes sense. However, one surmises that the
brain does not solve differential equations, per se, in the
computational or mathematical sense. Actions are too inaccurate. A
better proposition might be that the case of stone throwing involves a
big adaptive feedback loop - with an external loop [involving the
target] and a number of internal [to the brain and organism] loops.
The key is that feedback loops adjust their outputs by making
comparisons.

All together, the stone-throwing problem involves real-time visual
perception [of the target], tactile input [re stone weight, size,
etc], long-term memory [ie, remembrance of earlier and similar
experiences], short-term memory [ie, successive comparisons], and
requisite motor actions [ie, stone throwing]. Motor actions alone
involve several internal feedback loops, and the other aspects factor
into the larger feedback loop.

No one simply picks up a stone and throws it dead on-target. Even
professional baseball pitchers and football quarterbacks have to warm
up and get their systems essentially "calibrated" every time anew.
What happens is these guys throw the ball, and then use the results of
the toss to adapt their next throws. The major factor is feedback
comparisons stored in STM from one toss to the next. The loop and
motor actions are adapted each time, depending upon whether the
previous toss went long or short, etc. Even so, you never get perfect
repetitions, because the processes involve "estimation" rather than
hard calculation.

So, each stone toss involves real-time visual perception, comparison
to stored experiences, comparison to previous tosses, and active
adaptive adjustments of motor actions. This is not quite the same as
getting a solution using differential equations. Feedback and
comparisons in STM are the key factors.

You can probably make a case that each new action is almost an
open-loop or ballistic action, based upon "internal adjustments"
involving "comparisons" with the short-term memory of the previous
action [as stored in all relevant subsystems in the brain] - more so
than a direct calculation each time. The first throw is more or less a
guess, successive throws are mainly feedback adjustments. In addition,
each new throw is not quite an open-loop action, because you can also
sense how your muscles and joints are moving during the action [due to
the proprioceptive feedback loops, etc], and adjust the action even
while it>s proceeding - eg, finish strong, finish weak, twist, halt,
etc - because all actions take time to complete.

Feedback loops and real-time comparisons. What do you think?
[/quote]
This was exactly my point in suggesting analog computing versus
digital computing.

Regards - Lester

remove DEL in address for email

Gorne · Guest

Copy theory is inadequate because the brain does not produce copies of
external phenomena. It generate interpretations based on some
incomplete analysis of the phenomena>s measurement. It is a very poor
way to represent that phenomena, unfortunately it is the only one
available to date.

Joe Legris · Guest

dan michaels wrote:
[quote]Joe Legris <jalegris@xympatico.ca> wrote in message news:<3F4FF727.4080605@xympatico.ca>...

If you define a model as a simplified representation of a system then it
is not a copy by definition. End of argument.

Models in the brain are distillations of the aspects of reality that are
relevant to the organism. For example, a brain may contain a ballistic
model that allows one to predict where a thrown rock will land. The
relevant aspect of such a model is the relationship between perceived
heft of an object and it>s expected trajectory when thrown with a
particular effort. It is conceivable that the brain actually solves the
differential equation of motion using a neural network that has been
tuned over years of practice.

Much of what you say above makes sense. However, one surmises that the
brain does not solve differential equations, per se, in the
computational or mathematical sense. Actions are too inaccurate. A
better proposition might be that the case of stone throwing involves a
big adaptive feedback loop - with an external loop [involving the
target] and a number of internal [to the brain and organism] loops.
The key is that feedback loops adjust their outputs by making
comparisons.

All together, the stone-throwing problem involves real-time visual
perception [of the target], tactile input [re stone weight, size,
etc], long-term memory [ie, remembrance of earlier and similar
experiences], short-term memory [ie, successive comparisons], and
requisite motor actions [ie, stone throwing]. Motor actions alone
involve several internal feedback loops, and the other aspects factor
into the larger feedback loop.

No one simply picks up a stone and throws it dead on-target. Even
professional baseball pitchers and football quarterbacks have to warm
up and get their systems essentially "calibrated" every time anew.
What happens is these guys throw the ball, and then use the results of
the toss to adapt their next throws. The major factor is feedback
comparisons stored in STM from one toss to the next. The loop and
motor actions are adapted each time, depending upon whether the
previous toss went long or short, etc. Even so, you never get perfect
repetitions, because the processes involve "estimation" rather than
hard calculation.

So, each stone toss involves real-time visual perception, comparison
to stored experiences, comparison to previous tosses, and active
adaptive adjustments of motor actions. This is not quite the same as
getting a solution using differential equations. Feedback and
comparisons in STM are the key factors.

You can probably make a case that each new action is almost an
open-loop or ballistic action, based upon "internal adjustments"
involving "comparisons" with the short-term memory of the previous
action [as stored in all relevant subsystems in the brain] - more so
than a direct calculation each time. The first throw is more or less a
guess, successive throws are mainly feedback adjustments. In addition,
each new throw is not quite an open-loop action, because you can also
sense how your muscles and joints are moving during the action [due to
the proprioceptive feedback loops, etc], and adjust the action even
while it>s proceeding - eg, finish strong, finish weak, twist, halt,
etc - because all actions take time to complete.

Feedback loops and real-time comparisons. What do you think?
[/quote]
Sure, that sounds reasonable. I never meant to imply that there is a
little digital calculator or logic unit churning out precise
preprogrammed results. But the feedback loop and internal comparisons
you mention may be a neural network that is tuned, through practice, to
arrive at a result that approximates the solution of a differential
equation, given "boundary conditions" in the form of cortical and
sensory signals.

--
Joe Legris

Lester Zick · Guest

On 31 Aug 2003 12:30:20 -0700, boa4@optonline.net (Gorne) wrote:

[quote]Copy theory is inadequate because the brain does not produce copies of
external phenomena. It generate interpretations based on some
incomplete analysis of the phenomena>s measurement. It is a very poor
way to represent that phenomena, unfortunately it is the only one
available to date.
[/quote]
No one I know seriously suggests that copy theory is a viable
description of cognitive processes. The only question is whether
particular ideas are variations on copy theory or represent some
categorically different approach to interpretation of external
phenomena such that the results can be interpreted as a mind and
mental processes as distinct from brain processes.

Regards - Lester

remove DEL in address for email

Glen M. Sizemore · Guest

What we call visual stimuli "turns on" behavior. It no more represents the
world than the electricity that turns on the light is a representation of
the battery or the light.

"Wolf Kirchmeir" <wwolfkir@sympatico.can> wrote in message
news:jbysxveflzcngvpbpna.hkgwcg2.pminews@news1.sympatico.ca...
[quote]On Sat, 30 Aug 2003 20:42:45 GMT, Glen M. Sizemore wrote:

GS: I just don>t have the taste for metaphor and tautology that you do
Wolf.

That suggests that you believe that some sort of non-metaphorical
description
is possible.

Well, do you?

--
Best Wishes,
Wolf Kirchmeir, Blind River ON
"Not that brains are everything --
you>ll also need a skull to put them in." (Nancy Franklin, 1997)
just one w and plain ca for correct address

[/quote]

Lester Zick · Guest

On Sun, 31 Aug 2003 19:10:50 -0400 (EDT), "Wolf Kirchmeir"
<wwolfkir@sympatico.can> wrote:

[quote]On Sun, 31 Aug 2003 22:50:35 GMT, Lester Zick wrote:

Well as far as this goes the idea of a programmed machine implies a
programmer of necessity I would think. A universe on the other hand
would not imply anything except itself. What we seem to have here is
some suggestion of deism.

All living organisms are programmed machines.
[/quote]
Well that seems to be the issue. Or if so the extent and manner in
which they are machines and are programmed.

If you choose to define them as programmed then there is obviously an
issue with respect to how they are programmed. And if they are
machines the kind of machine they are. I don>t think the answer can be
assumed or simply defined.

And if we choose to think of them as programmed machines in the same
sense as digital computers it would be interesting to speculate on the
nature of the microcode involved.

Regards - Lester

remove DEL in address for email

Lester Zick · Guest

On 1 Sep 2003 07:37:22 -0700, dan@oricomtech.com (dan michaels) wrote:

[quote]Joe Legris <jalegris@xympatico.ca> wrote in message news:<3F52657B.1020309@xympatico.ca>...

..............
You can probably make a case that each new action is almost an
open-loop or ballistic action, based upon "internal adjustments"
involving "comparisons" with the short-term memory of the previous
action [as stored in all relevant subsystems in the brain] - more so
than a direct calculation each time. The first throw is more or less a
guess, successive throws are mainly feedback adjustments. In addition,
each new throw is not quite an open-loop action, because you can also
sense how your muscles and joints are moving during the action [due to
the proprioceptive feedback loops, etc], and adjust the action even
while it>s proceeding - eg, finish strong, finish weak, twist, halt,
etc - because all actions take time to complete.

Feedback loops and real-time comparisons. What do you think?

Sure, that sounds reasonable. I never meant to imply that there is a
little digital calculator or logic unit churning out precise
preprogrammed results. But the feedback loop and internal comparisons
you mention may be a neural network that is tuned, through practice, to
arrive at a result that approximates the solution of a differential
equation, given "boundary conditions" in the form of cortical and
sensory signals.

I>ve been reading about cortico-cortical interconnection pathways in
the brain recently - esp Edelman>s stuff. It>s quite interesting. The
white matter is composed of billions of fibers, most of which
represent feedforward and feedback connections within the cortex
itself. Feedback activity on a truly massive scale - far beyond
anything that engineering or mathematics can currently deal with.
Edelman shows a diagram of a cat brain with about 60 areas and over
1100 [large] pathways interconnecting these areas. Just a single 1-D
feedback loop in an engineering system can produce seemingly marvelous
effects - so one can imagine that billions of feedback pathways might
produce something akin to "magic" [to use a nonscientific word].

Regards analog-vs-digital, as Lester mentioned ... in engineering,
there are both analog and digital feedback systems, so theoretically
either can work. The mathematics of digital feedback is fairly recent
- arising largely with the advent of small digital computers. In the
brain, you could conceivably have both types in operation. OTOH, I
happen to be under the opinion that the spikes are there mainly as a
means for high-speed communications between neurons over distance, and
that the real key is in the postsynaptic integration - after the spike
activity is converted at the synapses. IOW, digital is there mainly to
support the analog - just my opinion.
[/quote]
Just as regards analog computing sophistication: I actually seen and
used an analog computer that solved 4D gunfire problems in real time.
Its design was WWII.

Regards - Lester

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Wolf Kirchmeir · Guest

On 1 Sep 2003 07:37:22 -0700, dan michaels wrote:

[quote]Regards analog-vs-digital,
[/quote]
Anything a digital computer can do, an analog computer can do, but not vice
versa.

--
Best Wishes,
Wolf Kirchmeir, Blind River ON
"Not that brains are everything --
you>ll also need a skull to put them in." (Nancy Franklin, 1997)
<just one w and plain ca for correct address>

John · Guest

Yes, feedbacks and loops, ubiquitous throughout brains. At the other end of
the spectrum, consider that of tracking a fast moving target. Research last
year showed that the eye does not "watch the ball" but rather anticipates
its trajectory and looks ahead, adjusting its targeting accordingly. Makes a
lot of sense when you consider how much training is required to throw
something or catch something. If it were simply a matter of finding the
right equation why the inaccuracy and why the error rate? Additionally, some
studies I have read on animal orientation suggest that various attempts to
find mathematical models to fit the observations just don>t work. They come
close but not close enough.

--
johnYYYcoe@tpg.com.au

remove YYY in reply
"dan michaels" <dan@oricomtech.com> wrote in message
news:4b4b6093.0308310841.3cce83e9@posting.google.com...
[quote]Joe Legris <jalegris@xympatico.ca> wrote in message
news:<3F4FF727.4080605@xympatico.ca>...

If you define a model as a simplified representation of a system then it
is not a copy by definition. End of argument.

Models in the brain are distillations of the aspects of reality that are
relevant to the organism. For example, a brain may contain a ballistic
model that allows one to predict where a thrown rock will land. The
relevant aspect of such a model is the relationship between perceived
heft of an object and it>s expected trajectory when thrown with a
particular effort. It is conceivable that the brain actually solves the
differential equation of motion using a neural network that has been
tuned over years of practice.

Much of what you say above makes sense. However, one surmises that the
brain does not solve differential equations, per se, in the
computational or mathematical sense. Actions are too inaccurate. A
better proposition might be that the case of stone throwing involves a
big adaptive feedback loop - with an external loop [involving the
target] and a number of internal [to the brain and organism] loops.
The key is that feedback loops adjust their outputs by making
comparisons.

All together, the stone-throwing problem involves real-time visual
perception [of the target], tactile input [re stone weight, size,
etc], long-term memory [ie, remembrance of earlier and similar
experiences], short-term memory [ie, successive comparisons], and
requisite motor actions [ie, stone throwing]. Motor actions alone
involve several internal feedback loops, and the other aspects factor
into the larger feedback loop.

No one simply picks up a stone and throws it dead on-target. Even
professional baseball pitchers and football quarterbacks have to warm
up and get their systems essentially "calibrated" every time anew.
What happens is these guys throw the ball, and then use the results of
the toss to adapt their next throws. The major factor is feedback
comparisons stored in STM from one toss to the next. The loop and
motor actions are adapted each time, depending upon whether the
previous toss went long or short, etc. Even so, you never get perfect
repetitions, because the processes involve "estimation" rather than
hard calculation.

So, each stone toss involves real-time visual perception, comparison
to stored experiences, comparison to previous tosses, and active
adaptive adjustments of motor actions. This is not quite the same as
getting a solution using differential equations. Feedback and
comparisons in STM are the key factors.

You can probably make a case that each new action is almost an
open-loop or ballistic action, based upon "internal adjustments"
involving "comparisons" with the short-term memory of the previous
action [as stored in all relevant subsystems in the brain] - more so
than a direct calculation each time. The first throw is more or less a
guess, successive throws are mainly feedback adjustments. In addition,
each new throw is not quite an open-loop action, because you can also
sense how your muscles and joints are moving during the action [due to
the proprioceptive feedback loops, etc], and adjust the action even
while it>s proceeding - eg, finish strong, finish weak, twist, halt,
etc - because all actions take time to complete.

Feedback loops and real-time comparisons. What do you think?[/quote]

dan michaels · Guest

"John" <John@overhere.com.au> wrote in message news:<3f53e5b5@dnews.tpgi.com.au>...
[quote]Yes, feedbacks and loops, ubiquitous throughout brains. At the other end of
the spectrum, consider that of tracking a fast moving target. Research last
year showed that the eye does not "watch the ball" but rather anticipates
its trajectory and looks ahead, adjusting its targeting accordingly. Makes a
lot of sense when you consider how much training is required to throw
something or catch something. If it were simply a matter of finding the
right equation why the inaccuracy and why the error rate? Additionally, some
studies I have read on animal orientation suggest that various attempts to
find mathematical models to fit the observations just don>t work. They come
close but not close enough.

--
johnYYYcoe@tpg.com.au

[/quote]

BTW, I thought I>d mention ... Berthoz starts out his book on The
Brain>s Sense of Movement in a way I find rather intriquing:

"This book is a reflection on how the brain works, based on the idea
that the brain is used to predict the future, to anticipate the
consequences of action (its own or that of others), and to save time.
To this end, very diverse biological mechanisms developed over the
course of evolution ... these mechanisms endowed the brain with
internal models of the world and of the body - not just any models,
but models that reflect the laws of nature, the Umwelt of each species
.... The brain is not a reactive machine; it is a proactive machine
that investigates the world ..."

This should tell you if the book might be of interest, or not.


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