[From Rick Marken (951128.2130)]
Bruce Abbott (951128.1625 EST) --
The pigeon was very unlikely to be responding to some simple
discriminative stimulus reliably associated with her appearance in the
picture, since one was not present.
See how hard it is to let go of that old S-R perspective.
The pigeon was "unlikely to be responding to some simple discriminative
stimulus", not because one was not present, but because THE PIGEON IS A
CONTROL SYSTEM; it doesn't respond to stimuli; it controls perceptions.
The pigeon was responding in order to compensate for a disturbance to a
controlled variable; a disturbance created, at least in part, by the
girlfriend's picture.
So when you say:
This experiment revealed something of importance about the capabilities
of the pigeon's visual perception system.
I think you are stretching things a bit. You are actually learning precious
little, if anything. The pigeon experiment you describe is precisely
equivalent to the thermostat experiment Bill Powers described recently. In
the thermostat experiment the experimenter tries to determine whether a
variable -- the degree of openness of the window -- affects the response of
the thermostat -- whether the heater goes on or off. The experimenter
finds that the heater goes on when the window is open and off when it is
closed. Like the pigeon, the thermostat makes a discriminative response to
a disciminative stimulus. The experimenter concludes that the thermostat
can perceive openness and respond appropriately. Just to prove it, he does
the same experiment with the front door and, voila, the same result; the
thermostat is an openness detector if there ever was one.
Ah, but you don't believe that a mere thermostat can detect something as
complex as openness, so you test it yourself. You put a screen between the
window and the thermostat; if the thermostat really detects openness it
cannot differentially respond to this variable if it cannot see whether the
window is open or not. Lo and behold, when the screen is present the
thermostat's response becomes unreliable; sometimes it responds when
the window is open, sometimes not. It looks like the thermostat CAN
detect openness .
To fully understand this analogy , you have to imagine that you don't
know any more about the thermostat than you do about the pigeon. That
is, you must make believe that you don't know that the thermostat
controls temperature (or that it controls AT ALL). The thermostat (like
the pigeon) is just something that appears to respond to environmental
events.
And you also have to pay no attention to that man behind the screen
(between the window and the thermostat); the one who is suggesting that
you measure variables near the thermostat that might be influenced by the
openness of the door and window and the presense or absence of the
screen; variables like illumination, humidity, pressure, and temperature
that might be controlled by the thermostat. He's just a crazy PCTer who
keeps repeating "controlled variable, controlled variable..."; just cover
your ears and have a good time doin' that old time conventional IV-DV
research; it tells you so much, don'cha know.
Bruce asked:
2. What is the method used (control or IV-DV)?
I replied:
Conventional IV-DV;
And Bruce replied:
The question, my dear Marken, was whether the pigeon could learn to
control (maximize) its access to grain when doing so required it to
perceive a complexly varying visual pattern as the "same" object. It could.
Gee. It looked to me like the question was:
2. What is the method used (control or IV-DV)?
I didn't even see the word "pigeon" in the question. I'll try to remember
my medication so that I can pay better attention next time;-)
Best
Rick