[From Dick Robertson,2004.05.19.0600CDT]
Can't find the exec.file in the posts for the various cube files.
Bill Powers wrote:
[From Bill Powers (2004.05.09.1342 MST)]
Martin Taylor 2004.05.09.10.15 --
Since I don't seem to get the "attractor" notion yet, I thought I'd do
something with ambiguous figures. Attached is an interesting experiment in
a preliminary form that others might want to expand on and improve. It's a
dynamic Necker cube and the zipped attachment is called DynaNeck.zip.
The source code for Delphi is included as well as the executable code (the
executable file is called Project2.exe, since I didn't bother to change any
files from their default names. You can rename it something more sensible).
A cube is shown on the screen which, with the mouse cursor centered on the
screen, wanders in two angular directions around the face-centered
orientation. The mouse can also rotate the cube left-right and up-down. The
object of the task is to use the mouse to keep the view exactly
face-centered.(that is, the rear square exactly behind the front square, so
the figure appears to be a single square).
An experimental run lasts for one minute. The angular errors are recorded,
and after the run are plotted, x in red and y in green.
As you will see, this task is devilishly hard. Since no perspective is used
(the z dimension is suppressed), there is absolutely no way to tell which
is the front square and which is the back one. As a result, the effect of
the mouse on whichever square you think you're watching changes sign each
time you inadvertently switch perceptions. This leads to a momentary
runaway condition followed by a recovery, as in the paper by Rick and me in
_Mind Readings_. These are fairly easy to see as spikes in the plot, and
will probably become more obvious with a well-practiced subject.
There are other orientations of the cube that the participant can try to
maintain -- I've done almost no experimenting with this yet. When the
Necker effect occurs, the sign of feedback would presumably change, causing
the runaway and recovery when the controlling person switches the sign of
the output to get back to negative feedback.
The screen is sampled 60 times per second; there are 3600 data points. The
data are not yet recorded in a file -- if anyone's interested I'll add that
so you can import the numbers in ASCII to other programs like spreadsheets.
Other suggestions are welcome, though I hope someone will volunteer to take
over the improvements to this idea.
Note that while there are switches in perception, the switch is not just
between one static configuration and another one. The whole figure is
affected even while its orientation is changing. And if preliminary
appearances hold up, the switch is strictly perceptual, since it seems to
cause a positive feedback situation whenever it occurs, with the output
function then switching to compensate some time later -- 400 milliseconds
later, if we extrapolate from the paper in _Mind Readings_.
A similar thing can be done with bubbles and dents by adjusting the shading
in a circular image according to Lambert's Law. I hope someone else beats
me to it. I'm really working on other things.
DynaNeck.ZIP Type: Zip Compressed Data (application/x-zip-compressed)