Post 1: Inhibitory Control Trials

My Upperclassmen Monroe Project focused on continuing research I had started with the IIBBS lab (Institute for Integrative Bird Behavior Studies) under Professor John Swaddle. My project examined the effect of the anthropogenic neurotoxin, methyl mercury, on the cognitive abilities of zebra finches. In order to study the perturbation of zebra finch cognition, I spent the summer conducting inhibitory control tests on the birds. This test was designed to assess a bird’s ability to inhibit their natural response to environmental cues in order to complete a task.

My experimental trials consisted of two stages: the first trained the birds to feed correctly from the testing apparatus, and the second presented them with a challenge that directly tested their inhibitory control abilities. I first baited an opaque plastic tube (approximately 10cm in diameter) with food in order to train the birds to enter the tube through the openings at the end. Once a bird had successfully eaten from the opaque tube three consecutive times it continued on to the testing phase. In this phase, the opaque tube was replaced with a clear plastic tube of the same size. At the start of these trials, the bird was on a perch and the tube was placed so that the bird could see the food through the clear plastic side of the tube. To correctly pass the test, the bird must inhibit its natural impulse to fly directly towards the food. Instead, it must go around the side of the tube in order to access the food (see attached diagram for visual). A bird would fail if it were unable to access the food or pecked at the tube side before going through the opening at the end. Conversely, in order to pass a trial the bird must proceed directly to the side of the tube. This demonstrates that the bird has learned how to access the food and is able to inhibit its natural response in favor of the learned response. Each bird went through this trial 7 to 10 times. The trials were recorded and video analyzed to determine time to complete trial and whether the bird passed each trial.  Each bird was then scored with an average time to feed and percentage of trials passed.

These trials are pretty straightforward to run but as with many types of scientific tests, required a lot of troubleshooting and tweaking. I spent most of the fall semester doing this and so finally getting to continuously run my trials was extremely exciting! I was also quite surprised while analyzing the video; I saw extreme variation in bird performance.

Tessa Diehl Cage Setup