Where is the proof? Information of disturbance

CSGnet Archive CSG1993
1

******** FROM CHUCK TUCKER 930328 ********

Some time ago Rick (930315.1500) stated that his research in "Mind Readings"
Chapter 3 ("The Cause of Control Movements in a Tracking Task" proved
"... THERE IS NO INFORMATION ABOUT DISTURBANCE IN THE PERCEPTUAL SIGNAL
CONTROL SYSTEM. This means that THE PERCEPTUAL INPUT TO A CONTROL SYSTEM
CANNOT BE WHAT CAUSES THE OUTPUR OF THE SYSTEMN (sic) TO MIRROR THE
DISTURBANCE." Reading his article again I don't believe that he
proves that al all; in fact, the subjects did have an awareness of
a disturbance - they were told about it and through several test runs
of the task knew that a disturbance was influncing the cursor - it is
the case that they did now know WHAT is was (neither did Marken - it was
random). In the study "Subjects were tested individually. Each subject
was seated before the videodisplay and asked to keep the cursor aligned
with the target by turning the game paddle appropriately. After several
practice sessions subjects were tested in 20 experimental runs...(63)."
I would have refused to published this study since WHAT the subjects
were told is not to be found in this description BUT having done
this type of work I know that they had to be told something (unless all
of the subjects had done this many times) BUT IT SEEMS OBVIOUS TO ME
THAT THE SUBJECTS WHERE AWARE THAT A DISTURBANCE WAS INFLUENCING THE
CURSOR POSITION ALONG WITH THEIR MOVEMENT OF THE GAME PADDLE. If this
investigator believes otherwise let him present evidence that they
were ignorant of a disturbance. He should has ASKED THEM or used THE
TEST.

2

[From Rick Marken (930328.1500)

CHUCK TUCKER (930328)

Some time ago Rick (930315.1500) stated that his research in "Mind Readings"
Chapter 3 ("The Cause of Control Movements in a Tracking Task" proved
"... THERE IS NO INFORMATION ABOUT DISTURBANCE IN THE PERCEPTUAL SIGNAL
CONTROL SYSTEM. This means that THE PERCEPTUAL INPUT TO A CONTROL SYSTEM
CANNOT BE WHAT CAUSES THE OUTPUR OF THE SYSTEMN (sic) TO MIRROR THE
DISTURBANCE." Reading his article again I don't believe that he
proves that al all

Good. This is all I want; look at the research. (By the way, did I use
the word "prove" -- it's not in quotes above? If I did, I'm sure
I meant it to be synonymous with "test" rather than "deductive proof").
So why doesn't my experiment "prove" this to your satisfaction? You say
it's because:

the subjects did have an awareness of
a disturbance - they were told about it and through several test runs
of the task knew that a disturbance was influncing the cursor - it is
the case that they did now know WHAT is was (neither did Marken - it was
random).

Two problems here: 1) they were not told about the disturbance -- though
they could surely tell that it was present and 2) it was a sine wave,
not random (though it works just as well with a filtered random
disturbance).

But I don't see what either of there points (subject's being aware of
the disturbance and the disturbance being random) has to do with the
point of the paper: that there is no information in the cursor movement
that can be (or is being) used by the subject to determine how to make their
responses? I assume "information about the disturbance" means that there
is some something about cursor movement (p(t)) that allows the subject
to compute o(t) -- ie. o(t) = f(p(t)) -- so that o(t) = -kd(t). The
experiment you read showed, I think, that there is no f() that could be
turning p(t) into o(t) because you get virtually the same o(t) twice
when you use the same d(t) but p(t) is totally different on each occassion.

I would have refused to published this study since WHAT the subjects
were told is not to be found in this description BUT having done
this type of work I know that they had to be told something (unless all
of the subjects had done this many times) BUT IT SEEMS OBVIOUS TO ME
THAT THE SUBJECTS WHERE AWARE THAT A DISTURBANCE WAS INFLUENCING THE
CURSOR POSITION ALONG WITH THEIR MOVEMENT OF THE GAME PADDLE. If this
investigator believes otherwise let him present evidence that they
were ignorant of a disturbance. He should has ASKED THEM or used THE
TEST.

Does this study upset you, Chuck?

Why would the subject's being aware or not aware of the disturbace
make any difference? The subject can certainly tell that there is
a disturbance operating and I would have reported that fact if
I (or anyone) could have seen why it would be germain. What is
far more important is "did the subject have any idea about the nature
if the function d(t)". In fact, one clever reviewer (Tom Bourbon, it
was, before he fell into the PCT all the way) pointed out that,
because I used sine waves, the subject could tell from their own
hand movements what the disturbance function was. Tom suggested that
the subjects could be producing the sinusoidal outputs from memory.
This was a far-fetched, but at least pertinent, criticism of my study.
I pointed out that the phase and frequency would have been impossible
to predict on the repetition trials (which were non-continguous and
the subject had no way of knowing when the d(t) on a particular trial
was a repetition of the d(t) on a previous one-- but, still, I should have
done the study with random disturbances. In fact, I have done the study
(just the other day) with random disturbances and it works just the same.

So it looks like your only complaint about the study is that the
subjects were aware of the disturbance; in fact, they would be
aware of the distrubance whether I told them about it or not; they
know that they have to do something to keep the cursor on target.
I think it would be hard to keep the subject "unaware" of the
existence of the disturbance. So I guess I have to ask how this
awareness might affect the results -- ie, the fact that the correlation
between output traces on two (very separate) trials with the same
disturbance was typically .99+ while the correlation between p(t)
(the only thing the subject could see on those trials) was typically
less than .2, once as low as .0032?

Best

Rick

3

***************** FROM CHUCK TUCKER 930329 ***************

So, the subjects, contrary to your claim that they didn't, DID have
information that a disturbance was going to influence the cursor and
randonness was invloved; you stated: "The phase and frequency of the
disturbance were determined randomly for each run. The same distur-
bance was repeated on pairs of nonconsective runs (63, in Reader)."
That the actual form of the disturbance was not known by either you
or the subjects (BTW, your description of the subjects leaves open
the possibility that one is you - a real problem if so) BUT the point
is that you previous stated that the subject had NO INFORMATION about
a disturbance; that simply is not true if your own description (as poor
as it is) is an accurate representation of what was done in the study.

You can translate all the words into other symbols (sy=symbols) and
put ='s, +'s, or any other sign you care to between them and they
still turn out for me to be words; I still have to read them to have
some idea of what you might be stating; actually I find your use of
such symbols a pretention on your part to appear to be systematic and
scientific when your research does not have such features for me.

YES, this study (and all others that I have seen you do) does bother
me. It does so because it is so poorly done that I would not consider
it worthy of inclusion in a list of scientific work. The claims that
you make for such work are usually not supported for me by your
study. You never indicate to the reader WHAT you have told the subjects
to do; this for me is basic in all research - what procedures were used
in the study!!! (e.g., I just found out in your answer to my post that
you did not TELL the subjects that there was a disturbance - did you
use deception in this study? - if you did this creates not only empirical
problems for me it creates some serious ethical ones - I hope you aren't
lying to your subjects in your research !?!). I suggest that you begin to
consider language and words more seriously in your research.

BTW, I found some more Markenisms that were not mentioned by Greg but
may have served as data for Ken:

     Rick (930307.1500)

     It's why we say PCT is revolutionary. I know that it seems
     impossible that all the old revered theories in psychology are
     invalidated by the work of a noce engineer from Chicago who
     doesn't even have a PhD in psychology - but that's the fact
     Jack."

     Rick (930312.1300) to Randall (930312.1200)

     "There is no information about the disturbance in the stumulus.
      Goodby behavioal science as usual, hello looney bin."

     Rick (930315.0900)

     "Actually this is not intentional; Bill P. is just a truly
      wonderful person and I am a schmuk."

I have a sense that you and I don't use a similar criterion to make a
judgment on whether a statement is categorized as "hyperbolic" but I
do judge the first two statements that way; the last statement is just
a half-truth.

Best regards,

        Chuck

4

[Martin Taylor 930330 11:20]
(Rick Marken various)

(930315.1500 as an example)

"... THERE IS NO INFORMATION ABOUT DISTURBANCE IN THE PERCEPTUAL SIGNAL
CONTROL SYSTEM. This means that THE PERCEPTUAL INPUT TO A CONTROL SYSTEM
CANNOT BE WHAT CAUSES THE OUTPUR OF THE SYSTEMN (sic) TO MIRROR THE
DISTURBANCE."

Let's consider a thought experiment to test this. If I understand the
claim, oft repeated, Rick means that no function that takes as input
(a) the perceptual signal and (b) any other signal that is agreed to have no
information about the disturbance can reconstruct the disturbance, but
that nevertheless the disturbance is mirrored in the output.

I'll leave the logical problem with the "mirroring" unaddressed, and
assume that Rick accepts as correct what he says, that the output
mirrors the disturbance.

In my thought experiment, I will take the ECS, and add a simple function
that takes as its input the reference signal to the ECS (which I think we
can agree has no information about the disturbance) and the perceptual
signal, which Rick CAPITALIZES as having no information abou the disturbance.
Let us see whether a function can be constructed that takes these two
inputs and produces a signal that matches the disturbance. If so, I
would consider it conclusive evidence that information about the disturbance
is to be found in the perceptual signal.

             ------------> Signal X (which should match the disturbance)
            >
       mystery function M(r, p)
        ^ ^
        > >
        > > V (reference signal R(t) into ECS)
        > > >
        > <-------|
        > V
        >---------->comparator------- error = P-R
        > >
    perceptual output
     signal P(t) function O(error)
        ^ |

···

                          V

        > output signal
        > (accepted as mirroring the disturbance)

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

If Signal X matches the disturbance, the perceptual signal must be the
route from which the mystery function M(r, p) gets the information about
the disturbance. Right?

Now let the function M be indentical to O(R-P). Signal X will then be the
negative of the output signal, which is the disturbance. The only question
here is whether O(error) is a function or a magical mystery tourgoodie. I
prefer to think we are dealing with physical systems, and that O is a function.
Therefore, information about the disturbance is in the perceptual signal,
and moreover, it is there in extractable form.

QED.

(Actually, QED is too strong, since I imagine most of us will want to
challenge Rick's claim that the output mirrors the disturbance. But that
way lies the argument to information rate, which I will pursue whether or
not Rick accepts that way out of the Q that ED.)

Martin