Sniffy Assignment #2 - Schedules of Reinforcement in Operant Conditioning

due Tuesday, Apr. 4

In this assignment you will train your rat on various schedules of reinforcement. Collaboration is not allowed, you should complete this assignment on your own.

READINGS: Before beginning this assignment you should read Chapter 12 of the Sniffy Pro book.

1. Starting with a rat trained to press a bar on a continuous schedule, change the schedule to a VR-5 schedule. Once your rat is responding steadily on a VR-5 schedule SAVE your rat using a new filename.

2. Gradually increase the ratio to a VR-60 schedule. Follow the instructions for exercise 32, being sure to use several intermediate schedules. Save your rat with a new filename.

3. Once you have your rat on a steady VR-60 schedule, start giving it some non-contingent reinforcers. You can do this by pressing the space bar every 2 seconds or so. Do this for 2 minutes and watch what happens to your rat's rate of responding.

4. Starting with your VR-5 trained rat, try jumping immediately to a VR-60 schedule without any intervening schedules.

5. Starting again with a fully shaped rat on a continuous schedule, train it to a FR-40 schedule, see exercise 34, but end at FR-40, not FR-60. Save this file, then put this rat on extinction. Once extinction is complete, save again using a new file name.

6. Starting again with a fully shaped rat on a continuous schedule, train it to a FI-40 schedule, see exercise 35, but again stop at FI-40. Save this file, then put this rat on extinction. Once extinction is complete, save again using a new file name.

7. Starting again with a fully shaped rat on a continuous schedule, train it to a VI-40 schedule, see exercise 33. Save this file, then put this rat on extinction. Once extinction is complete, save again using a new file name.

The Write Up

Be sure to read page 31 on how to copy images from Sniffy to another program.

For your write up you will need to answer the following 7 questions.

1. Give a brief description of what you did during this second Sniffy assignment.

2. a. Show the part of the cumulative record where you first put your rat on a VR-5 schedule.

b. Show a part of the cumulative records for a rat responding on a VR-60 schedule, that is, a rat that is showing steady responses on a VR-60 schedule.

c. Show a part of the cumulative records for a rat responding on a FR-40 schedule.

d. Show a part of the cumulative records for a rat responding on a FI-40 schedule.

e. Show a part of the cumulative records for a rat responding on a VI-40 schedule.

3. What happened to the rate of responding when you started giving your rat free (non-contingent) food?

4. What happened when you tried to jump from a VR-5 to a VR-60 schedule? Why do you think this happened.

5. Which took longer to extinguish, a FI-40 or a FR-40 schedule? Why do you think this is? Which would take longer to extinguish, a FR-40 schedule or a FR-25 schedule? (hint: if you want to do this experiment you can and include the data to support your answer).

6. How do you think extinction of the FI and FR schedules would compare to extinction of a continuous schedule of reinforcement? Why?

7. If you had a real rat, how would you set up a conjunctive schedule with two different schedules of reinforcement (you can pick the schedules but use ones different than those provided as examples in the book or in class)?