Re: Ontology of Experience
Steven Lehar
Rickert >
The image on a photodiode array is not a representation. As you said, in a
different message, "Whether or not something is a representation depends on
whether somebody or something uses it as a representation." But the image
on the photodiode array is not normally being used.
< Rickert
Oh come now, let us not get entangled in terminology. A photodiode array is
manufactured for the express purpose of turning a light image into a video
signal. It is a representation by design, whether it is currently turned
on, or being read by a process further downstream, or not. But even if we
acknowledge your contention that it ceases to be a representation when
turned off, you cannot deny that it is a representation when it is turned
on and passing its image on to a computer for processing. And the retina
is a representation for the same reason.
You are attempting to deny the very clear and obvious parallel between the
[eye, optic nerve, and the brain], and the [video camera, cable, and
computer] by a play of words that defines neither of them a representation.
But the video image is certainly a representation. There is no denying that
without perverting the definition of representation.
And the definition of representation is perfectly clear. Webster: "to serve
to stand for or denote, as a word or symbol does", for example like an
electrical voltage that represents the brightness of light at some point in
a light image. And like the electrical state of a retinal cone that
represents the brightness of a color component of a point in a light image.
Steve
Neil W Rickert
>Neil Rickert wrote:
>Rickert >
NR>The image on a photodiode array is not a representation. As you said, in a
NR>different message, "Whether or not something is a representation depends on
NR>whether somebody or something uses it as a representation." But the image
NR>on the photodiode array is not normally being used.
>< Rickert
SL>Oh come now, let us not get entangled in terminology.
Like it or not, we are already entangled in terminology. Steven's
argument for representationalism is partly a terminological dispute.
SL> A photodiode array is
SL>manufactured for the express purpose of turning a light image into a video
SL>signal.
That's a somewhat metaphorical description. The photodiode array is
quite ignorant of whether there is a light image. It is, more
accurately, generating a video signal from the state of excitation of
the diodes that make up the array. Any imagistic qualities are quite
irrelevant to the operation of the array. The individual diodes are
detecting only the light signal that strikes them, and not any
imagistic qualities.
The ordinary term "representation" has to do with the semantics (what
is represented). The operation of the photo-diode has to do only
with syntactic details (which photo cells are excited).
The output of the photo-diode array might be transmitted to a video
display, and there used to generate a varying light pattern on the
video display. That image of the video display is a representation,
for we use that image to determine semantic properties. But any
image that can be said to be on the photo-diode array is merely part
of the mechanism and is not a representation. We are not looking at
the image on the photo-diode array. Nor is the video camera. No
component is considering the semantic aspect, or the imagistic
qualities. There is simply a transduction of light signals into
electrical signals.
SL>You are attempting to deny the very clear and obvious parallel between the
SL>[eye, optic nerve, and the brain], and the [video camera, cable, and
SL>computer] by a play of words that defines neither of them a representation.
There is no obvious parallel. The evidence suggests that neurons in
the retina and optic nerve are already extracting semantic
information. This is quite different from what happens with a video
camera.
SL>And the definition of representation is perfectly clear. Webster: "to serve
SL>to stand for or denote, as a word or symbol does", for example like an
SL>electrical voltage that represents the brightness of light at some point in
SL>a light image.
We see no denotation with respect to the image on the photo-diode
array.
It is one thing to say that an output electrical voltage represents
the brightness of light at a point. I have no argument with that.
It is quite another thing to say that the image on the photo-diode
array represents.
-NWR
Marina Rakova
Neil Rickert wrote:
> There is no obvious parallel. The evidence suggests that neurons in
> the retina and optic nerve are already extracting semantic
> information. This is quite different from what happens with a video
> camera.
>
Could I please have a couple of references?
Thank you,
Marina Rakova