PSYC210 Lab –Winter 2013
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Psychology 210
Winter Lab Manual
Focus: Operant Conditioning
Lab Computer Program: “Sniffy” (The Virtual Rat)
Aim: Train Sniffy to bar-press for food on a Continuous Reinforcement Schedule and 4 different
Partial Reinforcement Schedules
Grade Determination: Participation (5%)
Lab Assignment –Due Week of Apr. 1st (7.5%):
Questions on the topic and experiment to be completed -5.5%
Cumulative Records from the computer program to be submitted -2%
Contact Info:
jlayes@stfx.ca – www.stfx.ca/people/jlayes
epencer@stfx.ca – www.stfx.ca/people/epencer
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 WHAT IS OPERANT CONDITIONING AND HOW WILL WE ACHIEVE IT?
Operant Conditioning increases the rate of a desired behavior by contingently reinforcing that
behavior once it occurs. In our lab, we will Operantly Condition a virtual rat named “Sniffy” to
bar-press, by rewarding him with food pellets. Sniffy may not spontaneously perform this
behavior on his own so we will first need to shape his behavior through successive
approximation, where we will reward him for performing actions that are increasingly similar to
the one we want to train. Once Sniffy does learn to associate bar-pressing with food-pellets there
are two different ways he can be reinforced: Continuously or Partially. When on a Continuous
Reinforcement (CRF) Schedule, Sniffy receives a pellet every time he bar-presses; when on a
Partial Reinforcement (PRF) Schedule, Sniffy receives a pellet sometimes, but not every time
he bar-presses. The timing of reward on a PRF schedule differs depending on whether it is a
Fixed Ratio (FR), Variable Ratio (VR), Fixed Interval (FI), or Variable Interval (VI)
schedule. “Ratio” refers to a number of bar-presses being the determinant for reward; “interval”
refers to a period of time elapsing as the determinant for reward. “Fixed” means that there is a
specific, set amount of bar-presses, or time required to pass, before reward will be given;
“variable” means that the number of presses or the period of time, changes slightly, and reward
will be given around an average amount of presses or time. For example, if you are training on a
VR5 schedule, this means that after about 5 bar-presses Sniffy will get a reward. In other words,
he may get rewarded after 3 presses, after 4 presses, after 5 presses, after 6, etc. Sniffy does not
know exactly when he will be rewarded. If it were a FR5 schedule, he would get reward after
exactly 5 presses every time. On a VI5 schedule, reward would be given when Sniffy responds
after about 5 seconds. On a FI5 schedule, reward would be given when Sniffy responded exactly
5 seconds after previous reinforcement.
 WHAT IS THE PURPOSE OF THIS LAB ASSIGNMENT?
This lab assignment allows you to humanely learn about observational techniques, magazine
training, shaping behavior, reinforcement schedules, acquisition, and extinction.
You will learn the steps to training an operant response and see how varying the reinforcement
schedule affects learning and extinction.
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 STEPS TO COMPLETING THIS LAB:
You are responsible for completing the lab outside of class if more time is needed.
1. Record Sniffy’s Baseline Behaviors
2. Magazine Train Sniffy
3. CRF Train Sniffy –
**STOP** -SAVE YOUR CRF TRAINED RAT TO H: DRIVE – DON’T SAVE OVER
4. Extinguish the CRF trained Sniffy
5. Observe Sniffy’s Spontaneous Recovery
6. Open original CRF Trained Sniffy.
PRF Train Sniffy –Begin with VR 25 Schedule: Train and Extinguish
7. Open original Sniffy. Train on a VI 25 Schedule and Extinguish
8. Open original Sniffy. Train on a FR 25 Schedule and Extinguish
9. Open original Sniffy. Train on a FI 25 Schedule and Extinguish
 USING THE COMPUTER PROGRAM:
To Start the Program:
After you log on to a campus computer, from the “Start” menu select “My Computer”, then
“Apps on ‘caesar’(S:)”. Double-click on the “Sniffy” folder, and then on the Sniffy icon.
Menu Information:
Under File, you can start a New animal, Open an experiment file, Save your files, and Exit.
**When Saving, be sure to change the save destination to your H drive.**
Under Parameters, you can define your training schedules, and study spontaneous recovery with
“Remove Sniffy for Time-Out”.
Windows Menu: There are two windows, one with the operant chamber and one with the
Cumulative Record: The cumulative record window has vertical lines that represent five-minute
intervals. Up to five pages of data can be saved by the recorder; each record runs for two hours.
***NOTE:*** THINK ABOUT WHAT YOU ARE SAVING BEFORE YOU CLICK SAVE!
-You are responsible for saving your progress, and not overwriting your trained Sniffy
-You are able to save Sniffy at any time, and the cumulative records and his progress will be
maintained until next time. At the end of each lab, be sure to save your work.
-You should have a file saved under a new name for each segment of the experiment, so that if
unsuccessful in any step, you can simply start over from the previous one, (e.g. “CRF”, “CRFext”, “FR”,
“FRext”…etc.
-As you work on one segment, you can overwrite the same file as you progress, (e.g. if you are
training on CRF for several labs, each Save can be an overwrite).
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 INSTRUCTIONS FOR CONDUCTING THE EXPERIMENT:
Step 1: Recording Baseline Behaviors
First, observe what actions your untrained subject naturally exhibits (baseline behaviour).
Observe Sniffy for 10 minutes to become familiar with the rat’s repertoire of behaviour. Make a
list of things he does and identify at least five actions you see him exhibit -save this list.
Second, find what his Baseline Bar-Pressing Rate is:
After 10 minutes of observation, establish the baseline frequency of bar pressing per minute. The
cumulative record shown at the bottom of the screen shows a tick mark every time the rat was
reinforced for bar-pressing. The vertical lines represent five-minute blocks. Therefore, count the
number of ticks from the start of the cumulative record up to the second vertical line and divide
by 10 to calculate the number of bar presses per minute. Keep this number in your records. (Note:
His baseline rate will likely be zero)
Step 2: Magazine-Training Sniffy
Wait until Sniffy is away from the magazine (where food pellets are delivered), then mouse click
on the bar above the magazine (or press the space bar) to deliver a food pellet. After Sniffy finds
and eats the pellet, immediately give him another pellet. Continue training for 10 to 15 more
approaches (i.e. 20 – 30 food pellets). Wait until the rat has left the magazine area and
subsequently returned before initiating another training trial. Your rat should now be trained to
approach the magazine whenever a food pellet is delivered. To test that your rat has been trained,
wait until Sniffy is in a corner away from the food magazine, then deliver another reinforcer. If he
is magazine trained, he will make his way over to the magazine to eat right away. Record how
long magazine training took to accomplish.
Step 3: CRF Training Sniffy
One popular procedure for doing this is called shaping by successive approximations. It
involves reinforcing activities that are more and more similar to the bar pressing response until
the animal begins to make that response. To be effective, the reinforcer must be delivered to
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Sniffy immediately after the target behaviour has started. The skill involved is to identify and
move through the appropriate steps. If you reinforce one action too often, Sniffy may fixate on it.
You must now decide which activities approximate bar pressing and how closely they do so. So,
you may start by rewarding him for reaching up on a side wall, for reaching up on the back wall
(gradually begin to reward more often for the back wall than for the side wall but not so much
that he will fixate), and/or for drinking water, and also if he, by chance, presses the bar on his
own, or even if he just walks by the magazine. Gradually get him to “realize” that bar pressing
equals reward by rewarding him for increasingly similar behaviour. You must pay careful
attention to the screen at all times for this step. If he barpresses and you miss it, and miss
rewarding it, this could impede training.
When you are successful, you will see Sniffy press the bar four or five times within One minute.
When that happens, stop delivering pellets with your mouse or space bar and let Sniffy press the
bar himself. Over the next several minutes, the response rate will climb; the cumulative record
will grow steeper. When the cumulative record line reaches the top of the record, it will reset
down to the bottom and continue climbing back up. Conditioning is considered complete when
the pen resets a second time (i.e., once it climbs up and drops down two times).**Observe and
record Sniffy’s behaviour and rate of responding within a 2 minute time period, upon acquisition
of this response.
Now Save your trained rat. It is suggested that you save your trained rat as CRF. sdf. Now you
have your own Sniffy to use in the remaining steps of the experiment. You need to save it on your
h:drive (there is a pull-down menu at the bottom of your save window- make sure you’ve
selected your h:drive and NOT the s:drive). After saving, it is suggested that you Exit the
program and restart the Sniffy program. Open your file of a successfully trained Sniffy before
extinction and let Sniffy run for one minute under a Continuous Reinforcement schedule (CRF)
then begin Step 4 below.
Step 4: Extinguishing Behaviour after CRF Training
Open your CRF trained Sniffy and allow him to run for one minute on a CRF schedule. Then:
Select “Training Schedules” in the “Parameters” menu and click “Extinction”. This means that
Sniffy will no longer be reinforced for bar pressing. Then click OK.
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Time and record the period from when you instituted extinction until extinction is complete (this
is the extinction baseline) and count and report the number of non-reinforced bar presses during
the first two minutes. Bar pressing behavior is extinguished when Sniffy presses the bar
fewer than three times in five minutes.
** Select “SAVE AS” in the file menu and save this file under a new name. You must save it
as a new name to ensure that you do not overwrite the original file of a “trained” Sniffy. **
Step 5: Observing Spontaneous Recovery:
To observe the effects of a time-out after extinction, select “Remove Sniffy for Time-Out” in the
“Parameters menu”, select “OK”. Be certain that the Training schedule remains on “extinction”.
Count and record the bar press responses for two minutes. Measure and report the time from
when Sniffy returns to the cage until bar pressing is extinguished again (i.e. Less than three
presses in five minutes).
*Save, and now Print a copy of your cumulative record to be handed in at end of term.
**BEGINNING OF PRF TRAINING**
PRF schedules are changed using the Training Schedules under the Parameters menu. Fixed
schedules are chosen by clicking the “Fixed” button and Variable schedules are chosen by
clicking the “Variable” button. Ratio schedules are chosen by clicking the “Responses” button
and typing an integer in the number-entry box. Interval schedules are chosen by clicking the
“Seconds” button and typing an integer in the number-entry box.
Open the program following the above directions, and open a copy of your CRF trained rat (unextinguished). Systematically work through training and extinguishing your CRF trained rat on
all four PRF schedules using the following instructions.
Step 6: Training Sniffy on a VR 25 Schedule
Open your original CRF Trained Sniffy (that hasn’t gone through Extinction).
Once you have let Sniffy run untouched on a CRF schedule for one minute you can begin to make
the transition to the VR 25 target by changing Sniffy to a VR schedule. Do this by selecting
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“Variable” and “Responses” in the Parameters menu. Note that you cannot just put 25 in as your
first value; you MUST start with a small PRF schedule and gradually increase it after the
animal’s behaviour stabilizes at each value. It is probably best to start with a very low value (4 or
5) and work in small interval increases (intervals of 5, perhaps). Sniffy’s behaviour will be
extinguished if you choose too large a value when you first place him on a PRF schedule. If
Sniffy is maintaining bar pressing at a stable rate for 15 food pellets on that schedule, then he has
learned the new schedule and can then be trained on the next interval until the target value is
acquired (i.e., wait until Sniffy receives at least 15 pellets before moving up to the next interval).
For example, you may wish to start Sniffy out on a schedule of VR 5. Wait until he receives 15
pellets on that schedule, and then try moving him up to VR 10. Wait another 15 pellets, and so on
until he has received 15 pellets on the VR 25 schedule.
**When Sniffy has received at least 15 pellets on the target schedule he is considered trained.
* Save your file under a new name
Extinction:
Next, you need to measure extinction after the schedule has been acquired. Use the same method
as in Step 4. Restart the program and open your saved VR25 Sniffy. Don’t forget to time and
record the period from when you instituted extinction until extinction is complete (the extinction
baseline) and count and record the number of non-reinforced bar presses during the first two
minutes.
*You do not need to do spontaneous recovery for the PRF schedules.
** Save, and Print a copy of your cumulative record**
Step 7: Training Sniffy on a VI 25 Schedule
Open your original CRF Trained Sniffy and let him run for one minute.
In the Parameters Menu select “Variable” and “Seconds”. Remember that you cannot start at 25
seconds; you must start with a small number and gradually increase it in intervals just as you did
in the previous step.
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When Sniffy receives at least 15 pellets on the target schedule of VI 25, save your file under a
new name.
Extinction:
Exit the program and restart.
Open your saved VI 25 Sniffy.
Follow the same instructions as in Step 4. Time and record the period from when you instituted
extinction to when it was complete (extinction baseline) and count and record the number of nonreinforced bar-presses in the first two minutes.
**Save, and Print your cumulative records**
Step 8: Training Sniffy on a FR 25 Schedule
Open your original CRF Trained Sniffy and let him run for one minute.
In the Parameters Menu select “Fixed” and “Responses”. Again, increase the number of
responses in small intervals until you reach the target number of 25.
When Sniffy receives at least 15 pellets on the target schedule, save your file under a new
name.
Complete Extinction just as you have in the previous steps. Record the same information as
in the previous steps.
**Save and Print your cumulative records.**
Step 9: Training Sniffy on a FI 25 Schedule
Open your original CRF Trained Sniffy and let him run for one minute.
In the Parameters Menu select “Fixed” and “Seconds”. Again, increase the number of responses
in small intervals until you reach the target number of 25.
When Sniffy receives at least 15 pellets on the target schedule, save your file under a new
name.
Complete Extinction and record the same information as recorded in the previous steps.
**Save and Print your cumulative records**
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 LAB ASSIGNMENT –DUE WEEK OF April 1ST
Answer the following 15 questions. Use your textbook to help, but be sure to use
your own words. Attach your cumulative records at end (see next page).
Please type your numbered answers in APA format and submit, with an APA Title
and Reference page, to Janea’s office or the Lab Drop-Box in the Annex prior to 2
pm on the day your lab regularly takes place.
1. What are the two principles of Operant Conditioning, and why is this type of conditioning
also called “Type of R”? (Cite textbook)
2. In your own words, define CRF, PRF, FR, FI, VR, VI, and Spontaneous Recovery.
3. List 5 of Sniffys baseline behaviours.
4. What was Sniffy’s baseline bar-pressing rate, prior to any training?
5. How long did it take to accomplish magazine training?
6. Upon reaching acquisition during CRF training, describe Sniffy’s behaviour, and report his
rate of responding within a two-minute period.
7. After CRF training, what was the extinction baseline? How many non-reinforced barpresses were there during the first two minutes of extinction?
8. During Spontaneous Recovery, how many bar-presses were there during the first two
minutes? How long did it take to extinguish the behaviour again?
9. How did the rate of extinction after CRF training differ from the rate of extinction after
Spontaneous Recovery? Why would this be expected?
10. After FR 25 Training, what was the extinction baseline? How many non-reinforced barpresses were there during the first two minutes of extinction?
11. After FI 25 Training, what was the extinction baseline? How many non-reinforced barpresses were there during the first two minutes of extinction?
12. After VR 25 Training, what was the extinction baseline? How many non-reinforced barpresses were there during the first two minutes of extinction?
13. After VI 25 Training, what was the extinction baseline? How many non-reinforced barpresses were there during the first two minutes of extinction?
14. Looking at your own results, order the 5 different reinforcement schedules in terms of
their rate of extinction (from fastest to slowest). What should the expected order be, and
why? (This will be discussed by Dr. Pencer in class. Cite your lecture notes using the
Personal Communication format, including the date of the class). Do the current results
agree with the expectations?
Don’t miss Question 15 is on next page….
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15. Relate operational conditioning, and your knowledge of the various training schedules
and their patterns, to the real world. How is this knowledge useful? (About half a page)
ATTACHING YOUR CUMULATIVE RECORDS:
You should have records printed for:
-CRF Training, Extinction, and Spontaneous Recovery (Steps 1-5)
-VR 25 Training and Extinction (Step 6)
-VI 25 Training and Extinction (Step 7)
-FR 25 Training and Extinction (Step 8)
-FI 25 Training and Extinction (Step 9)
-Label each set of records at the top of the first page, with a pen/pencil.
-On each set of records, with a pen, indicate when acquisition was complete, when
extinction started, and when extinction was complete.
-Attach at the end of your assignment in the order listed above.
-Avoid handing in multiple copies of the same record:
-Try to avoid attaching multiple copies of the same steps whereever this is possible.
In other words, don’t attach FR training, and then FR training with extinction; just
attach the latter copy that includes both steps.
(You can print as often as you choose, just don’t include extras in the assignment)
GOOD LUCK WITH THIS ASSIGNMENT! 