Artificial Sight

Glen M. Sizemore gmsizemore at triad.rr.com
Thu Jul 26 16:54:18 EST 2001


>>The eye does not "send messages" and the brain
> >does not "interpret
> > anything."
> >
>
>
> MJ: Speak for yourself.
>
> -MY- eye sends messages, and -MY- brain
> interprets them just fine.
>
> If this didn't happen, I wouldn't be able to see.
> What's the
> alternative way of thinking about it? Magic?
>
>
> GS: The fact that you can ask this question in this
> way shows how pernicious is the philosophy that
> stimuli are transferred into the body (as "messages"
> no less! - how quaint!) where they are seen or heard
> or "interpreted." In my opinion (and, admittedly, the
> minority opinion) this philosophy is the worst thing
> that ever happened to psychology, philosophy,
> behavioral neurobiology, and many other fields
> concerned with behavior.


MJ: Glen,

I normally hate to say any argument is "semantic". In
this case,
however, I believe that the disagreement can be
shown to reside in how
we are using the word "message".

GS: Hi Matt,
Yes, my argument is "semantic," but the implication
is that that renders it trivial. It is certainly
commonplace to simply say "Well, this is how I'm
defining 'message' or 'representation'" etc. This is
the unfortunate legacy of "operationism" in
psychology and the fields that it has contaminated
(despite the fact that this is apposite the original
spirit of operationism in physics). What it shows is
that psychology has pushed forward a sneering
disdain for conceptual analyses and championed the
associated notion that the terms one uses don't
matter as long as you "define your terms" and "stick
to the scientific method." So, yes, it is "semantic"
but "semantic" is about 1/3 of what science is. So,
no, the fact that my argument is semantic does not
render it trivial. Science must be a balance of
conceptual analysis, theory, and data. See, for
example, Machado et al's "Facts, concepts and
theories: the shape of psychology's epistemic triangle."

MJ: Apparently, you use "message" to indicate
something like a "purposeful
communication". I assume that's why you make the statement:

>It never fails to amaze me
> that people are so willing, when they are discussing
> the reduction of behavior to neurobiological
> processes, to describe the brain in the same terms as
> is used to describe the behavior of the whole
> organism.

GS: *I* am not defining "message." I realize that I
don't have that luxury. Or rather, *I* realize that to
take such license in these circumstances is nonsense
(see my comment on operationism). Even at this
point, I knew what you were about to say, right
down to citing Shannon. The problem is - and
speaking somewhat colloquially - that you can not
escape the meanings of colloquial terms by simply
redefining them to meet your philosophical needs.
Specifically, the ordinary usage of "information" and
"message" implies a PERSON "receiving," if not
both "receiving and sending." Ironically, even
though this aspect of the colloquial meaning is what
Shannon sought to eliminate by defining
"information" in physical terms, it is just that aspect
that allows positions like yours. After all, what is on
the receiving end of a telephone? No, not the
"receiver".....it is the person. What comes out of a
telephone "receiver" is not "interpreted" by the
telephone receiver - it is interpreted by the person.
Even if we refer to the activity of sensory organs
and "the things they are connected to" as
transducing a message (which is itself nonsense),
there is nothing to "interpret it as such" unless one
wants to posit an homunculus, albeit implicitly. See?
You want to say your are considering only the
analog of a telephone (both transmitter and receiver)
but the physics of the telephone are sterile with
respect to the issues that should matter to
psychology and behavioral neurobiology. A
telephone receiver does not "behave" in any way
that raises psychological (I prefer "behavioral")
issues.You want it both ways. You want to eliminate
all that is psychological but you want your telephone
analog to address psychological issues.


MJ: If I interpret this correctly, you are opposed to
thinking of
information processing in the brain as a dialog
among various
homunculi, who follow the same principles and
actions that the whole
organism does. I would certainly be opposed to this
too, because it is
a non-explanation, leading to the usual infinite loop
of non-answers.

GS: Right. And I still hold that, despite your
definition, this is an accurate characterization of
your position.

MJ: However, I (and I think, the story covered in
the original post) was
using the word "message" to refer to -any- signal
passing over a
communication channel that carries information. The
signals passing
over the optic nerve to the thalamus and cortex are certainly
"messages" in the information theoretic sense. One
can take the
analytical machinery of Information Theory, point it
at these signals,
and "decode" what the initial visual stimulus was
(see for example, J
Neurosci 1999 19:8036-8042 Reconstruction of
natural scenes from
ensemble responses in the lateral geniculate nucleus.
Stanley GB, Li
FF, Dan Y.). This message can be quantified, and its
accuracy in
carrying information about the visual stimulus can be
evaluated.
Absolutely -no- purposefulness, teleological cause
or homunculus needs
to be invoked. Frankly, I think it is -useful- to anthropomorphize.
But that pernicious opinion is beside the point.

GS: This is all beside the point. First,
"communication channel" begs the same issue. So
does "information," despite the fact that
"'information' may be given a particular
[mathematical no less!] definition" as in Information
Theory. Since you have defined "information," how
could it not be true that "The signals passing over
the optic nerve to the thalamus and cortex are certainly
'messages' in the information theoretic sense." It is
ironic that you raise the Stanley et al paper since it is
Stanley et al that do the interpreting! Or are you
saying that something in the brain acts as Stanley et
al!

MJ: Next, we'll need to clarify what we each meant
by "interpret". I
haven't thought about this as much, but i guess i
would probably lean
toward a definition something like this:
"Interpretation" is that
response which brings about actions that are
appropriate to the
message in such a way as to maintain the function of
the organism.

GS: But this is transparently vacuous. All it does is
assert that somehow neurobiology is relevant to the
functioning of the organism. Oh yeah.....it also
asserts that part of what neurobiology does is to
make (and no doubt store) copies of the world. So,
the world is taken into the brain on the analogy of
the telephone. But once there, you cannot say how
this copied world "brings about actions." This is the
weakness of mainstream cognitive psychology; the
making of copies cannot contain anything of import
to behavior without something to turn copies into
behavior. But wherever and whatever the analog of
the telephone receiver is "in the brain" it can only be
connected up with more stuff which can also be
given the same physical description. So how is it that
a copy "comes out as behavior?"

MJ: So, why not come up with different terms that
are less likely to be
confused as implying some sort of conscious intent?
I think because
the quantitative tools for understanding information
transmission were
originally developed to describe human
communication channels (i.e.
telegraph and telephone signals) in which intent is definitely
present.

GS: But it is not present in the telephone or
telegraph, and this is precisely my point.

MJ: However, if one looks at the original papers by
Shannon, this
intent disappears. The signal source is treated as a
random sequence
generator throughout Information Theory, and the
information content
of the message is a purely statistical description of
what was sent
and what was received. The important point being
that it is
quantitative, has a fair degree of predictive utility,
and is based on
mathematically well-formulated principles.

GS: Again, the telephone receiver does not interpret.
Information Theory is of little or no use to
behavioral neurobiology because it has nothing to do
with behavior. I have already stated what I think are
the central problems.

MJ: So I stick to my original statements: My eyes
send messages which my
brain interprets. If this didn't happen, I wouldn't be
able to see.

GS: I have already pointed out that this notion is
silly and distracting.

MJ: What's the alternative? The only alternative is
that seeing takes
place -without- the transmission of information
between the eyes and
the brain.

GS: Yes, it takes place without "information" except
when "information" is defined in such a way as to be
devoid of import to the analysis of behavior or its
potential reduction to nuerobiological events. In
such a case, it is no explanation at all.

Warmly,

Glen
"Matt Jones" <jonesmat at physiology.wisc.edu> wrote in message
news:b86268d4.0107230957.71bf3714 at posting.google.com...
> "Glen M. Sizemore" <gmsizemore at triad.rr.com> wrote in message
news:<QqF67.129068$ih.25099455 at typhoon.southeast.rr.com>...
> > >The eye does not "send messages" and the brain
> >  does not "interpret
> > > anything."
> > >
> >
> >
> > MJ: Speak for yourself.
> >
> > -MY- eye sends messages, and -MY- brain
> > interprets them just fine.
> >
> > If this didn't happen, I wouldn't be able to see.
> > What's the
> > alternative way of thinking about it? Magic?
> >
> >
> > GS: The fact that you can ask this question in this
> > way shows how pernicious is the philosophy that
> > stimuli are transferred into the body (as "messages"
> > no less! - how quaint!) where they are seen or heard
> > or "interpreted." In my opinion (and, admittedly, the
> > minority opinion) this philosophy is the worst thing
> > that ever happened to psychology, philosophy,
> > behavioral neurobiology, and many other fields
> > concerned with behavior.
>
>
> Glen,
>
> I normally hate to say any argument is "semantic". In this case,
> however, I believe that the disagreement can be shown to reside in how
> we are using the word "message".
>
> Apparently, you use "message" to indicate something like a "purposeful
> communication". I assume that's why you make the statement:
>
> >It never fails to amaze me
> > that people are so willing, when they are discussing
> > the reduction of behavior to neurobiological
> > processes, to describe the brain in the same terms as
> > is used to describe the behavior of the whole
> > organism.
>
> If I interpret this correctly, you are opposed to thinking of
> information processing in the brain as a dialog among various
> homunculi, who follow the same principles and actions that the whole
> organism does. I would certainly be opposed to this too, because it is
> a non-explanation, leading to the usual infinite loop of non-answers.
>
> However, I (and I think, the story covered in the original post) was
> using the word "message" to refer to -any- signal passing over a
> communication channel that carries information. The signals passing
> over the optic nerve to the thalamus and cortex are certainly
> "messages" in the information theoretic sense. One can take the
> analytical machinery of Information Theory, point it at these signals,
> and "decode" what the initial visual stimulus was (see for example, J
> Neurosci 1999 19:8036-8042 Reconstruction of natural scenes from
> ensemble responses in the lateral geniculate nucleus. Stanley GB, Li
> FF, Dan Y.).  This message can be quantified, and its accuracy in
> carrying information about the visual stimulus can be evaluated.
> Absolutely -no- purposefulness, teleological cause or homunculus needs
> to be invoked. Frankly, I think it is -useful- to anthropomorphize.
> But that pernicious opinion is beside the point.
>
> Next, we'll need to clarify what we each meant by "interpret". I
> haven't thought about this as much, but i guess i would probably lean
> toward a definition something like this: "Interpretation" is that
> response which brings about actions that are appropriate to the
> message in such a way as to maintain the function of the organism.
>
> So, why not come up with different terms that are less likely to be
> confused as implying some sort of conscious intent? I think because
> the quantitative tools for understanding information transmission were
> originally developed to describe human communication channels (i.e.
> telegraph and telephone signals) in which intent is definitely
> present. However, if one looks at the original papers by Shannon, this
> intent disappears. The signal source is treated as a random sequence
> generator throughout Information Theory, and the information content
> of the message is a purely statistical description of what was sent
> and what was received. The important point being that it is
> quantitative, has a fair degree of predictive utility, and is based on
> mathematically well-formulated principles.
>
> So I stick to my original statements: My eyes send messages which my
> brain interprets. If this didn't happen, I wouldn't be able to see.
> What's the alternative? The only alternative is that seeing takes
> place -without- the transmission of information between the eyes and
> the brain.
>
> Cheers,
>
> Matt





More information about the Neur-sci mailing list