Final Results

I have included a final weight/food chart, a bar graph indicating average bar presses per session, and a line graph exhibiting Tortellini's behavioral progression:

                                                

                                        

This has been such an enjoyable experience to be able to have during my undergraduate career. I am typically not excited about class projects, but this project has been so much fun. I even made a new friend--Tortellini! I honestly enjoyed every aspect of this project, so I have no complaints. It was incredibly surprising to see the rats press the bar from FR1 all the way up to FR20. The only challenge Tortellini and I experienced was keeping her attention on training. I had previously mentioned that I would have added another day of whichever schedule she did not train long for, but she was getting such a high number of bar presses. So I just kept increasing her FR schedule until we reached 20. I was also surprised at the relationship I built with Tortellini. If I knelt down by her cage, and my friend knelt down on the other side of her cage, she would always climb onto my shoulder instead of my friend's. I truly believe that Tortellini knows who I am, and I would have never thought that a rat could determine who its owner was. 
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Extinction: Days 1 & 2

The goal of today's session was to cease Tortellini's behavior of bar pressing. Extinction is done by not reinforcing the rat after it has performed the previously rewarded behavior. On the first day of extinction, Tortellini seemed extremely frustrated. As expected, she kept biting the lever and using more aggression to press it. Within the first minute of not receiving any rewards, she had already pressed the bar about 92 times. At around 8 minutes Tortellini had another extinction burst, where she kept pressing the lever at an intense rate. Her cumulative records indicate spontaneous recovery at about 22 minutes, where she pressed the lever 4 more times. Towards the end of the session she began to wander around the box, often waiting in the corner close to me.

Tortellini's frustration during extinction

Day 1: Extinction Cumulative Records

On the second day of extinction, Tortellini did not press the bar as many times as the first day. It was definitely apparent that she was beginning to understand she was not going to get rewarded anymore, thus there was no point in pressing the lever. Remember that on day 1 of extinction, Tortellini pressed the bar about 92 times within the first minute--today Tortellini pressed the bar about 92 times within the first 14 minutes. This shows progress since her behavior of pressing the bar is declining. Tortellini's cumulative record for day 2 also shows that she did not have an extinction burst or spontaneous recovery after those 14 minutes. On both extinction days, the number of bar presses were recorded every 5 minutes until 30 minutes was reached. 

Day 2: Extinction Cumulative Records

Table showing the number of bar presses per every 5 minutes on days 1 & 2 of extinction

Fixed Ratio Schedule: FR20

The goal for today's training session was for Tortellini to press the lever 20 times before receiving a treat. I don't think she was a fan of FR20. There were multiple times when she would press it 15 times, get frustrated, and then walk away. She still continued to bite the bar and search around it as if something was wrong with it. She also continued to use her back paws as leverage against the wall to press the bar with more intensity. Today's session lasted for 22.43 minutes, which is her longest session since magazine training. I was pleased with the length of her session, but her number of bar presses did decrease from FR15. On FR20 she pressed the bar 987 times, which is still a high number. I was just hoping she would press it more times than she did on FR15. 

FR20 Cumulative Records

Fixed Ratio Schedule: FR15

Today's goal was for Tortellini to press the bar 15 times in order to receive a reward. This training session was pretty much like the FR12 session. 3 more bar presses did not seem to make a difference in Tortellini's behavior or performance. She continues to show frustration through biting the lever and moving quickly around the lever as if she was trying to figure out what was wrong with it. This session lasted 18.46 minutes, which is longer than most of her sessions. Tortellini pressed the bar a total of 1046 times. I was expecting this number to be higher than her FR12 results. Maybe she becomes physically tired by having to press the lever so many times. It will be interesting to see whether she continues the pattern of growth or declination during FR20. 

FR15 Cumulative Records

Fixed Ratio Schedule: FR12

The goal of this session was for Tortellini to press the bar 12 times before being reinforced with a sugar pellet. She continues to exhibit behaviors that resemble frustration, such as biting the lever from all different angles. Despite her apparent frustration, she still manages to press the bar a substantial amount of times. Tortellini also continues to struggle maintaining her attention on training. This session lasted 19.36 minutes. If a session is much shorter than 30 minutes, you are supposed to train again on that same FR schedule. However, I hesitate to do that because Tortellini still presses the bar so many times. For example, during this session she pressed the bar 1052 times! If a rat is pressing a bar 1052 times, then I think it is appropriate to move on to a higher level! Tortellini is really doing a great job though--I am extremely impressed by her. 

FR12 Cumulative Records

Fixed Ratio Schedule: FR10

The goal of today's training session is for Tortellini to press the lever 10 times before getting a sugar pellet. So far this is the highest schedule I have put her on, so I was worried that she would struggle and become frustrated. However, she did a great job besides her short attention span. She may just be experiencing satiation from receiving so many reinforcements at the beginning. Her cumulative records for FR10 show when she began to slow down around 11 minutes. She lasted 15.07 minutes on this schedule before she quit pressing the bar completely. Tortellini pressed the bar 749 times on FR10. She is consistently exhibiting an increase in bar presses every time I move her up a level, which is right on track. 

FR10 Cumulative Records

Fixed Ratio Schedule: FR7

The goal of today's training session was for Tortellini to press the bar 7 times in order to receive a treat. This session was very similar to her session training on FR5, except she lost interest even quicker this time and she exhibited more aggression. Tortellini has begun to place one of her paws on the side of the box in order to gain some leverage to press the bar (shown in video). She also shows a lot more movement around the bar in comparison to when she only had to press it once for a reward. I have noticed on her cumulative records that she tends to press the bar a lot in the beginning, thus receive a lot of treats early on during the session. I am wondering if she becomes satiated due to the fast rate and frequency she is receiving sugar pellets. Today Tortellini only trained for 15.07 minutes; however, in that short amount of time she pressed the bar 664 times. This is by far the most bar presses Tortellini has performed yet. 

FR7 Cumulative Records