Eliza and I have been getting acquainted this week. She was smaller than I expected. A fellow classmate had me convinced that she would be . . . well, huge. She is not huge. She is actually one of the smaller rats. She seems to have a rather calm demeanor, and is actually quite sweet. She squealed at me a few days ago. I’m not really sure why. Maybe it wasn’t at me, but it took me by surprise and, quite honestly, scared me a bit. I got over it, especially when another fellow classmate, who was present in the lab and witnessed the squeal, pointed out that she could sense my fear. I took a deep breath, picked her up and we’ve been getting along just fine. I made an attempt at “clicker training” today. All I can really say about that for now, is – tomorrow is another day.
Well, I went back and combed through the research after Eliza’s seemingly lack of fear in phase 3 and 4. What I discovered was that, not surprisingly, rats may react differently to fear stimuli and stressors. There are different types of fear response behaviors. It is not all flight, or fight, or freezing. There is also “risk assessment” behavior, when escape is not possible. This would be a little more like the “fight” option, but does not always have to be so aggressive. Risk assessment is alot like the term implies. It involves sniffing and other exploratory behaviors which describe the behaviors Eliza displayed. So, I an inferring from her behavior based on the research that she was not unafraid, but perhaps less afraid, but still engaging in risk assessment behaviors.
It turns out that according to literature, Brooklyn may be showing more of an intense fear reaction rather then habituation. There have been instances where mass trialing caused a compound effect of fear in an animal and blocked movement. The literature stated that these animals experience a Kamin effect where they do well in the beginning of an experiment and then worsen only to recover responding at the end of the trials. The recovered responding usually happens when the animal is removed from the situation for a few hours. I saw this effect in Brooklyn. She would escape to the control boxes quickly until the 15th trial and then would not leave the control box. I had to stop the trials and start again that evening or the next day. Again she would start out with fast responses to the fear stimulus and then progressively take longer and longer to leave the holding area.
Another interesting possibility is the idea that animals give off situational olfactory cues. Because I removed the animals immediately from the box and then started a new trial there may have been olfactory cues of fear in the “safe boxes.” This would change the scent to “un safe” and cause the animal to extinguish responding.
Either way Brooklyn is exhibiting behavior quite different then Clementine and Eliza. Though handled , Brooklyn was not handled by Tammi and me. Could she deem us “strangers” and thereby not see our scent as reassurance?
Well Eliza’s numbers are in and it seems that the only rat that recovered discrimination is Clementine. We will know this for sure after we run statistics and see if any of the results are significant. To better see the results I have included a graph comparing each rats choice per condition per phase. final-graph-depicting-choices-over-all-4-phasesAs you can see Clementine had higher choice of handler overall but was not as consistent in this choice as Eliza. All three rats showed considerable more interest in food when in a no fear condition as was expected. However, we did not think we would loose discrimination in the phase 3 fear condition. I wondered if having all three conditions as ” safe” options weakened the need for discrimination and upon discussing it with Tammi decided to try a Phase 4 using the scent of a cat. We tested all three rats and only saw a reemergence of discrimination in Clementine. Even more interesting then the lack of discrimination is the behavior around the cat hair. Clementine became aggressive, Eliza could have cared less and Brooklyn defecated on the hair consistently. Brooklyn actually preferred citronella and the cat over the handler scent… something I may have to take personally. Overall the results are surprising and we are combing research to try to make sense of it all. We have our work cut out for us. Let the research continue.
We have completed all four phases with all three rats! It is very exciting to be at this stage. We are now examining and comparing our data. We have had some interesting results and not exactly what we expected. We are beginning to speculate on what all of our results might infer about our rats choices and behaviors. Eliza still did not show fear to the predator sound during phase IV. This was not a surprise considering her lack of fear in phase III. However, she also did not seem particularly interested in (much less fearful of) the new scent of cat hair. It seemed to have no effect on her behavior at all. She calmly entered the box with the cat scent, examined the cloth, scratched at it a bit, smelled it, and calmly made her way out of the box. She did this for a total of eight times across 30 trials. She chose my scent 12 times, and the scent of citronella 10 times. Of course I cleaned boxes, and switched cloths around half way through the trials as I have been doing. This did not alter her behavior. We will run some statistics to see if there is a statistically significant difference among choices. All three rats choices in each of the four phases has been graphed, and shows how their choices compare.
Well all four Phases have been completed for Clementine and Brooklyn. I observed interesting behavior from both rats in the final phase where the Cat scent was presented along with the predator sound. Clementine would enter the cat box and attack the fur attempting to eat it. Brooklyn would enter the cat box and immediately defecate on the fur. In Phase 3 I noticed a loss of discrimination of scent during the presentation of the predator sound. I find it interesting that Clementine and Brooklyn scored the same number of choices but in different configurations. Clementine chose the handler scent 7 times, Citronella 11 times and the food 12 times. Brooklyn chose the handler 7 times, Citronella 12 times and food 11 times. The handler choice was constant but food and Citronella transposed. In the Final Phase (4), I saw more discrimination from Clementine in favor of my scent (handler) 16 over 9 for Citronella and 5 for Cat. Brooklyn did not show the same discrimination. She chose the Handler scent 6 times preferring Citronella 14 and Cat 10 times. I have included a graph of choice per phase and condition for all three rats all-three-across-four-word. I will add Eliza’s final data when she has completed phase 4.
Our next step is to run the statistics to determine if we have any significant choice behavior across conditions and Phases. We will see……
Well I am half way through the 30 trials with Brooklynn and the cat scent. Brooklynn is showing relatively no fear to the cat scent and a preference for the middle box regardless of scent present within the box. She also completely stops responding to the predator sound after 13 trials. I will have to complete the trials tonight. This behavior is consistent with what I saw when I presented the predator sound with food rather then the cat scent in the previouse Phase. Brooklynn stopped responding to the sound around 13 trials (15 to be exact) and I had to finish the trials that evening as well. I have not seen a habituation or non-responding behavior in Clementine. It will be interesting to see what Tammi experiences with Eliza in Phase 4.
When I looked a the results with phase 3 I was surprised. I thought I would see more discrimination. I went back to the literature and realized that unlike the studies I was reading all my conditions following the presentation of a predator sound were “safe”. I decided to implement a phase 4 using the scent of a cat in place of food to see if I would see discrimination if one of the boxes were no longer safe. clementine-phase-final-4. As you can see from the graph I did get more discrimination of scent when one of the conditions was not “safe”. Clementine surprised me by entering the cat box on 5 different occasions. He behavior was comical. Rather then sitting in the box grooming or snuggling up to the cloth as she does in the Citronella and my scent boxes, she pounced on the cat hair cloth and tried to eat the hair. He behavior was aggressive…. She is one tough rat:).