frequency of timely tomatoes

[Martin Taylor 970928 11:15]

Bill Powers (970928.0557 MDT)]

We can deal with "a tomato" as a perceptual
category without giving it a name other than "a tomato." No two tomatoes
are identical, but because we can deal with their different sizes, shapes,
degrees of ripeness, and locations of stems, we can _act as if_ they are
the same at a certain level of perception.

Interesting that you can say this. When I tried to claim this as an essential
aspect of "category" in a posting I thought of as "truth-saying", you were
very severe in your criticism of the notion.

However, I am glad you now seem to agree that it is so. Perhaps there is
a basis for some further rational discussion of category perception, a
possibility that seemed remote just a month or two ago.

ยทยทยท

----------------

Bill Powers (970927.1518 MDT)

You can't really talk about "frequency" except over a substantial time
period, technically an infinite time-period.

I don't know where you got that rule. I've never heard of it.

Oh, I know enough of your technical background to be almost certain that
you have. If not, I'm sure you can look it up in any of many of your old
books. It's not controversial or mysterious. Just a fact of life known to
any first year electrical engineering student.

But we do talk about short-
time "frequency" often enough that we forget this point.

Yes, indeed we do. Perhaps it deserves to be forgotten.

A _very_ dangerous suggestion if you are concerned with analyzing or
simulating things that change with any rapidity. More dangerous when
posted in a forum in which many readers are less knowledgable in the
area than I know you to be. Some of them might believe you to be serious.
_I_ know you can't be, but you could have made it clearer with a :-).

---------------

I have to confess to a personal interest in this matter, since 24 years
ago I wrote a paper ...

Sounds very powerful. How did the computer simulation work out?

That question is sensible to ask these days. It would not have been so at
the time.

Twenty-four years ago was 1973. I was doing computer simulations at that
time. So were lots of other people.

Including me. I did my first computer simulation of a neural network in 1963.
But this issue is a few orders of magnitude bigger than that, and was not
(I judge) feasible at the time, even though we were involved in some
fairly substantial use of computer time for other simulations around then.

It might even be feasible to try it now. However, the argument
was quite straightforward, and I would be rather surprised if it didn't
work out.

Might be a good idea to try it. That would be more persuasive than just
saying that you find your own idea convincing.

Yes, it certainly would. But you, too, could look at the argument and see if
_you_ find it convincing. I believe I sent you the paper some time ago.
But demonstration by simulation would be better than that, by a long shot.

Martin

[From Bill Powers (970929.0659 MDT)]

Martin Taylor 970928 11:15]--

We can deal with "a tomato" as a perceptual
category without giving it a name other than "a tomato." No two tomatoes
are identical, but because we can deal with their different sizes, shapes,
degrees of ripeness, and locations of stems, we can _act as if_ they are
the same at a certain level of perception.

Interesting that you can say this. When I tried to claim this as an
essential aspect of "category" in a posting I thought of as

"truth-saying", >you were very severe in your criticism of the notion.

You wanted to model category perception as cross-connections at each level
of perception. That is what I criticized.

However, I am glad you now seem to agree that it is so. Perhaps there is
a basis for some further rational discussion of category perception, a
possibility that seemed remote just a month or two ago.

Be careful what you assume I am agreeing to.

----------------

Bill Powers (970927.1518 MDT)

You can't really talk about "frequency" except over a substantial time
period, technically an infinite time-period.

I don't know where you got that rule. I've never heard of it.

Oh, I know enough of your technical background to be almost certain that
you have. If not, I'm sure you can look it up in any of many of your old
books. It's not controversial or mysterious. Just a fact of life known to
any first year electrical engineering student.

When you have a pulse-rate-modulated signal carrying voice information, the
maximum frequency component in the modulating signal is approximately the
frequency corresponding to the minimum interval between pulses, give or
take a factor of two. What's your problem with that?

A _very_ dangerous suggestion if you are concerned with analyzing or
simulating things that change with any rapidity. More dangerous when
posted in a forum in which many readers are less knowledgable in the
area than I know you to be. Some of them might believe you to be serious.
_I_ know you can't be, but you could have made it clearer with a :-).

I am perfectly serious; your hints that "you and I know better" are not
welcome. I can construct (and have constructed) a frequency detector the
output of which can change (90% response) in a time corresponding to two or
three cycles of the maximum frequency representable in the input train of
impulses (Geiger counter output). In simulation, I have demonstrated a
frequency meter that can respond to a change of frequency within less than
one complete cycle (by matching an oscillator frequency to the _waveform_
of the input).

While I haven't yet read the articles to which you referred, I will bet
that the temporal patterns observed were actually the averages over many
trials.
If there is a problem with measuring frequency accurately over a few
cycles, the reason would be exactly the same as the reason it is difficult
to measure a pattern of intervals over a few instances of the pattern.

---------------

... you, too, could look at the argument and see if
_you_ find it convincing. I believe I sent you the paper some time ago.
But demonstration by simulation would be better than that, by a long shot.

As you must know by now, I do not find "arguments" convincing without some
demonstration of their applicability.

Best,

Bill P.