1. Operant Conditioning: Sniffy the Rat
210 Lab Assignment #2 – 2014
Due: Friday April 4th (last day of classes)

2. Today
Brief background: Operant conditioning and the reinforcement schedules we’ll use
Using the Sniffy Program
Steps to completing the assignment
Walkthrough of CRF training (and brief explanation of how to start PRF training)
Assignment Outline – lab report

3. Purpose
The Sniffy program will help you understand operant conditioning and give you first-hand experience with these concepts:
Magazine training
Shaping behavior
Partial Reinforcement (PRF) schedules
Continuous Reinforcement (CRF)
Fixed Ratio (FR)
Variable Ratio Schedule (VRF)
Fixed Interval (FI)
Variable Interval (VI)
Acquisition
Extinction

4. Operant Conditioning
Increases the rate of a desired behavior by reinforcing that behavior when it occurs
In our case, we want Sniffy to bar-press
We will reinforce him with food pellets

5. Schedules of Reinforcement – Main Types:
Continuous Reinforcement (CRF)
Partial Reinforcement (PRF)
Rewarded some times when behavior occurs; not every time
e.g. Sniffy might press the bar 5 times and only get rewarded once.
Rewarded every time the desired behavior occurs
Every time Sniffy presses the bar, he will get a food pellet

6. PRF Schedules – 4 Types: Fixed Variable Ratio Fixed Ratio (FR)
- Reward happens after a set number of responses or time
Variable
- Reward happens around a certain average
Ratio
- Bar-pressing is the determinant for reward
Fixed Ratio (FR)
- Pellet is delivered after a set number of bar-presses
Variable Ratio (VR)
- Pellet is delivered after an average number of bar-presses
Interval
- Amount of time is the determinant for reward
Fixed Interval (FI)
- Pellet is delivered after a set amount of time passes
Variable Interval (VI)
- Pellet is delivered after an average amount of time passes 1 2 3 4

7. Materials needed
The lab manual (on Moodle)  read this before you start
Sniffy Program
On any campus lab computer:
Click My Computer  Apps on Caesar (‘S:’ drive)  Sniffy folder  double click the Sniffy icon to open the program
Stop watch, or stop watch app on your phone
Paper & pen

8. Project components Shaping an Operant Response: PRF Schedules:
Observe Sniffy’s base-line behavior for 10 mins
Magazine Training
Shaping Bar-Pressing by Successive Approximation
Extinction
Spontaneous Recovery
PRF Schedules:
Fixed Ratio 20  extinction
Variable Ratio 20  extinction
Fixed Interval 20  extinction
Variable Interval 20  extinction

9. Observing baseline behavior
For 10 minutes, observe Sniffy’s behavior
Pay attention to what he does and get an idea of what kind of behaviors you’ll be reinforcing later on
Planning ahead a bit will help with the next part
Record how many times Sniffy bar-presses on his own in the 10 minutes
DO NOT reinforce him

10. bar
water
magazine/hopper
The cumulative record (CR) will show you how Sniffy’s training is progressing
These dotted lines show you 5-minute increments

11. The ticks on the cumulative record show when Sniffy bar-presses
The ticks on the cumulative record show when Sniffy bar-presses. The line also moves up when he presses the bar, allowing you to track training progress. Sniffy may bar press a few. My Sniffy bar-pressed twice during the 10 min observation time.

12. Magazine Training
Using the spacebar or your mouse, drop a pellet from the hopper
When Sniffy approaches and eats it, give him another pellet
Consider Sniffy magazine-trained when he approaches the hopper as soon as you drop a pellet (10-15 reinforcements)
You can test his training by waiting until he is far away from the hopper (nearest to you) and dropping a pellet: if he goes to eat it, he’s magazine-trained

13. Training Sniffy to bar-press
Training by successive approximation
Reinforce behavior that is closer and closer to the desired behavior
Reinforce: drinking, rearing on the rear wall, going near the food hopper, passing in front of it
Fixation
If you reinforce one behavior too frequently (e.g. reinforcing rearing on the rear wall too many times in a row), Sniffy will fixate on that behavior, rather than what you are trying to shape
Note
I cannot stress enough how important it is to devote your FULL attention to this part of the assignment.
Training Sniffy to bar-press takes about 30 to 45 mins if you pay attention and reinforce him appropriately. It can take several hours if you aren’t giving it your full attention.

17. Immediately save Sniffy to your H: drive, USB drive, etc.
Bar-pressing cont.
Slowly wean reinforcement down to only when he is rearing near the bar, or in front of the magazine
Sniffy will start to bar-press by himself more and more frequently  stop reinforcing him manually and let him continue to bar press until the CR resets two times. Time him to make sure he’s bar-pressing at a frequency of 4-5 presses per minute. If he is, your training was successful!
Go to File  Save As  Name him something appropriate (SniffyCRF.sdf, etc.). You’ll be working from this saved Sniffy file several more times, so saving is vital. You don’t want to have to train a new Sniffy later.
Immediately save Sniffy to your H: drive, USB drive, etc.

20. My CR has resent by going back to the bottom twice.
At this point he’s bar-pressing 4-5 times per minute.

21. Extinction Trials
Click Parameters menu  Training Schedules  Extinction  Click OK
Sniffy will no longer be on a CRF schedule – He won’t get a pellet when he presses the bar
Time and Record:
Number of non-reinforced bar presses in the first 2 minutes of extinction
Time to complete extinction
(if he presses 3 times or less in 5 minutes we’ll consider that extinction)

23. Spontaneous Recovery
Next we’re going to test spontaneous recovery after a ‘time out’ (think of this as an overnight break from the chamber)
Click Parameters  Remove Sniffy for Time-Out  OK
After Sniffy is placed back in the chamber, time and record:
Number of bar presses in first 2 minutes
Amount of time required for Sniffy to completely extinguish a second time
Save this Sniffy (e.g. SniffyEXT.sdf) and print your results
You’re finished with CRF training!

25. Time out

26. Note on Cumulative Records
You will print a copy of CRF, extinction, and spontaneous recovery cumulative records to turn in with your report
Label the printout (in pen):
When was acquisition complete?
When was extinction instituted?
When was extinction complete?
When was spontaneous recovery instituted?
When was extinction complete the second time?
Print and make notes as you go through the steps, not after you’re finished everything – it might be hard to remember later.
Check the manual for more info on what you’ll need to print as you move through the steps, and what you’ll need to label on the printout for each training schedule

27. PRF Training I’ll show you how to do the one PRF training schedule
Fixed Ratio (FR) 20
Teach Sniffy to bar-press 20 times for a food pellet
The procedure to carry out this training schedule applies to all the others
First, open your original CRF Sniffy
We can’t start out with FR20, we have to start out with a lower ratio
Remember how fast extinction occurred? If we start out at FR20, or FR15, or FR10, it’s likely that he won’t learn the new schedule

28. Use for interval schedules
Use for fixed schedules
What I’ve selected means Sniffy will get a pellet after 4 bar-presses (FR4)

29. Sniffy’s response rate will be lower at first

30. Looks like he’s learned the new schedule

31. Wait until Sniffy has been reinforced 15 times, then increase the # of responses before reinforcement (by 3 or 4 responses)

32. Repeat these steps until you’re up to FR20

33. Tips
Give yourself lots of time to complete training – start as early as you can
I can give you rough estimates of how long each part will take:
Observing behaviour and magazine training: 30 mins
CRF – from 30 mins to an hour
Assuming you’re paying attention! I’ve been told it can take several hours if you’re not.
The PRF schedules (+ extinction) take about an hour each
If you forget to start your stopwatch, you can tell 2 minutes (or whatever time you need) using the CR and a ruler
Print the CR and label it before moving on to a new step.
Read the instructions fully before starting – it’s hard to do it as you’re working on training
Saved full labs from last term

34. Lab Assignment #2 Due April 4th (in class)
After you’ve trained Sniffy and printed your CRs, write a lab report detailing your findings
More info on lab report requirements are in the manual
Components:
Title page
Partial Intro
Outline hypotheses for each training schedule (how do you think they will they compare to one another?)
Method
Results
Report your observations made during steps outlined in the manual (acq/ext times, behavioural observations, etc.)
Discussion
Address questions listed in the manual
Refs (textbook, chapter 5)
CR printouts (labelled and with required notes)