Fixed Ratio 2

Date: 9/30/13

Start Time: 2:07

End Time: 2:37

Session Duration: 30:00

Number of Bar Presses: 154

Number of Rewards: 77

Snickerpuss’ Weight: 211

Goal:

Our goal was to train Snickerpuss to respond on a Fixed Ratio 2 schedule. On the FR-2 schedule Nicky would be rewarded for every two times she pressed the lever. We would consider Nicky to have successfully learned this reinforcement schedule if she achieved 60 rewards (one per 30 seconds of training).

Procedure:

Nicky weighed 211 grams, two grams over her target weight, on the day of training. Her slight gain in weight may have been a result of the increased number of reinforcements received during the last training session

For the seventh day of training, we put Nicky on an FR-2 schedule, which would reward her for every two lever presses. Since lever pressing was an automatic reinforcer, we were able to observe Nicky’s behavior while she was inside the operant box.

Results:

Nicky pressed the lever 154 times during our 30 minute training session, resulting in 77 rewards. Again, Nicky pressed the lever more today than in her previous training session, showing that she is still learning to associate the pressing of the lever with a reward. We considered Nicky to have learned the FR-2 schedule of reinforcement because she responded at a rate that resulted in more than 60 rewards for the 30 minute session.

Discussion:

            Nicky seems to be learning from her previous training sessions because she is pressing the bar more frequently in order to get more rewards. When she was first put into the operant box, Nicky seemed to be frustrated that she was not being rewarded for every lever press and she began biting the food hopper and repeatedly checking for a reward after each press. After approximately five minutes, she began to learn that she would need to press the bar more than once to be rewarded now. Once this association was made and she stopped checking the food hopper after each lever press, her frustrated behavior began to diminish as well. Since Nicky successfully learned the respond on an FR-2 schedule of reinforcement, we will move on to an FR-3 schedule of reinforcement in the next training session.

A video of Nicky during FR-2 training.

Cumulative Record of Fixed Ratio 2