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 19 Laboratory Exercise #3
Magazine Training
Objective:
To train the rat so that regardless of where it is or what it is doing, it will run quickly to
the dipper cup and drink whenever you operate the dipper.
Introduction
Magazine training might well be called "arranging for a reinforcing stimulus for use in
future conditioning." This step may also be thought of as an instance of a stimulus (the click of
the dipper mechanism) acquiring discriminative control of behavior (running to the dipper cup
and drinking). Stimulus control, which we will study in more detail in a later exercise, includes
components of both operant and classical conditioning.
In this exercise in particular, the process of classical conditioning is quite easily
identified. A neutral stimulus (the dipper motor sound combined with a click) is one that initially
has no effect on the behavior that we are trying to condition (running to the dipper cup and
drinking). In this study, the click and the unconditioned stimulus (US) of water are paired
together in a series of trials. Over time, the rat learns to associate the neutral click with the
unconditioned response (UR) of drinking. Once this association is learned (criterion is
accomplished), we say that the click is a conditioned stimulus (CS) for the conditioned response
(CR) of running to the dipper cup and drinking.
As the rat responds faster and faster to the sound of the click (the latency of his reaction
decreases), the operant conditioning component becomes more apparent. That is, the water is a
reinforcing stimulus (SR), so running to the water dispenser and drinking should increase in
strength over time. In addition, because the click is associated with the water, the click gradually
acquires reinforcing properties also; we say that the click is a secondary or conditioned
reinforcer (Sr).
What all this means is that whatever behavior immediately precedes the click and the
water is the behavior that is most likely to increase in strength or frequency of occurrence.
Therefore, the most important thing to avoid in this exercise is that of reinforcing the response of
crouching over the dipper cup. If you present the click while the animal is in this position, that's
where he will tend to remain. This, of course, will make it difficult to condition other behaviors
later on. Because the rat is spending so much of its time crouching over the dipper cup, other
behaviors that you want to reinforce will not be emitted frequently enough for you to have a
chance to strengthen them through reinforcement. To avoid this problem, wait until the rat leaves
the dipper cup before you start the next trial by activating the dipper mechanism again.
Magazine training is basic to all of the future studies you will do with the animal in this
apparatus; therefore, it must be well-established. Once this process is accomplished, any
20 responses in the animal's repertoire can be strengthened more easily and quickly. Do not become
discouraged if the rat seems to learn slowly; magazine training may be one of the most difficult
phases of conditioning. Once accomplished, other behaviors will condition more easily. Be
patient.
The unit of measure in this exercise is the trial. When the dipper mechanism is activated,
this marks the beginning of a new trial, and after the rat drinks the water and moves away from
the dipper cup, the trial ends. The behavior you will be observing is the latency of the rat's
response, or how long it takes the rat to run to the dipper cup and drink the water. Begin
counting from the activation of the dipper mechanism and stop when the rat put its nose in the
dipper alcove. This time, in seconds, is the latency.
In addition, you will also record the distance that the rat was from the dipper cup at the
beginning of the trial. Measure from the rat's nose to the dipper alcove using the measurements
on the front bottom edge of the chamber. Finally, note environmental changes that occur over the
course of the exercise because when you report the results, you may find that the animal changes
its behavior suddenly, and if you know that a door slammed or someone sneezed, you have a
possible explanation for the change.
When magazine training your rat, vary the amount of time between trials, so the rat does
not associate a particular time delay with the presence of water. In addition, vary the distances
from the dipper alcove and locations where the rat must be before the water is presented.
Note bene: The computer program for this exercise is set up to reinforce bar presses only
on the left or back lever in the chamber.
Read the procedure below carefully, making sure that you understand all of the steps
before you begin.
Procedure
Preparation:
1. Assign the various tasks to members of the group (timing, data recording, observation
of behavior), and make sure each member knows how to do his or her task.
2. Make sure the equipment is working correctly. Check the power connection and the
white molex connectors on the SmartControl module to make sure they are secure, and
make sure there is power to the chamber by pressing the black button on the back of the
dipper mechanism. This should raise and lower the dipper arm. Ask the lab instructor
for help if you have problems.
3. Ask the lab instructor to begin the appropriate computer program to turn the house light
on. (This program will also automatically reinforce a bar-press on the back, or left,
lever if it occurs.)
4. Weigh the rat.
21 5. Before placing the rat in the operant chamber, press the remote control button on the
dipper mechanism to activate it so the dipper cup is filled with water and available to
the rat.
Magazine Training:
6. Place the rat in the operant chamber.
7. Wait until the rat drinks the water in the dipper cup and leaves the vicinity before
pressing the remote control button a second time to release the dipper back into the
reservoir.
8. Record time. If the rat remains crouched over the dipper cup for longer than 3 seconds,
release the dipper mechanism.
9. After the rat is a short distance (record distance) away from the dipper alcove, activate
the dipper using the remote control. Wait until the rat drinks the water (maximum 5
seconds). Record the time. (See the Example Laboratory Record). Press the button on
the remote control to release the dipper back into the reservoir.
Exercise #2: Example Laboratory Record
Trial
Latency
(sec.)
Distance
(in.)
Changes in Environment
1
197
4
put rat in chamber
2
173
2
3
185
10
4
179
3.5
5
151
7
6
254
6.5
7
217
2
8
141
5.5
9
154
8
10
168
3
light in room brightened
10. Repeat steps 7 and 8, randomly varying the distance between the rat and the dipper
alcove and the location of the rat in the chamber, so the animal learns to approach the
cup from any position in the chamber. In addition, vary the amount of time between
trials, so the animal does not use time as a signal that reinforcement is available.
22 Note Bene: Be careful not to repeatedly reinforce any unnecessary or undesired behavior.
Criterion:
11. The rat responds to the click when the dipper operates from anywhere in the operant
chamber with a uniformly short latency, that is, 2 seconds or less, for 30 consecutive
trials. Then show the lab instructor 10 more consecutive trials.
Finishing up:
12. Weigh the rat, record its weight and put its back in the home cage.
13. Clean the chamber tray, and the table and floor around your workstation and the
weighing area.
14. The data recorder distributes readable copies of the data sheet(s) to each member of the
group. Each member of the group enters the data into his or her own computer file and
constructs his or her own tables and graphs.