[From Rick Marken (2006.01.25.1200)]
Martin Taylor (2006.01.24.23.26) --
Rick Marken (2006.01.24.1350)
I don't believe that cursor position is the variable controlled.
Isn't the object of your demo that the subject chooses one of the
cursors and controls its position according to any pattern (s)he sees
Oops. You're looking at the wrong demo!! The demo I was talking about is the "Nature of Control" tracking task. I suggested it to Erling as a way to get a feeling for the difference between passive perception, where you just look at the cursor while it moves, and active control of perception, where you control the perception of cursor position. All this other stuff about perceptions going to zero -- actually, I still have no idea how it came up but it is completely irrelevant to the original point, which is simply that we can perceive without controlling what we perceive, and we often do, like when we watch a movie or listen to a concert. We do control for the movie or concert we attend. But once selected we don't generally control what we see or hear at these events.
Here's the crux, very simply. You say, to paraphrase (I hope
correctly): Firing rate value non-zero indicates some value of the
perception; firing rate value zero indicates that the perception
doesn't have a value.
I said, in the bit you quoted up above: "In the absence of some
special functional organization not specified in any model I know,
this arrangement would mean that zero firing rate corresponds to a
perception of the most leftwards imaginable position."
Now you are asserting that there IS some such special functional
organization that changes the meaning of the perceptual signal when
its value is exactly zero. If its value is 10, 1, .1, .01, .001, the
thing perceived (in this case a position) is precisely that value,
but let that .001 be reduced by .001 and suddenly the thing perceived
is not that value. There's a new mechanism.
This is close to correct I would say that non-zero perceptual signals represent different _states_ of a perceptual variable (like different degrees of honesty) but that zero is a special case where you are not experiencing the perceptual variable at all -- you can't see the honesty of the statement, for example. But I see the problem you have with it and I'm not sure how to solve it. But your approach has a problem, too. If zero neural firing represents a state of the variable -- its lowest possible state -- then how to you represent the non-perception of the variable, even of it's lowest possible state?
Richard S. Marken, PhD
Loyola Marymount University
Office: 310 338-1768
Cell: 310 729 - 1400