Research 

Conditioning in Cockroaches

I have been working with cockroaches for the past few years as a controlled indoor alternative to the honey bee model I used during my PhD. I specifically use the orange head cockroach (Eublaberus posticus). This is a wonderful and practical laboratory species. In some ways they remind me of an insect version of a rodent model. At the moment, I have two publications on this work. The first is on habituation of a light-startle response. The second is on associative conditioning. Both papers are open access so you can click on the links below to read them. I also posted a video, which was originally an online presentation for the 2021 International Conference on Comparative Cognition.

Varnon, C. A., Barrera, I. E., & Wilkes, I. N. (2022). Learning and memory in the orange head cockroach (Eublaberus posticus). PLoS ONE, 17(8), e0272598. https://doi.org/10.1371/journal.pone.0272598

Varnon, C. A., Adams, A. T. (2021). Habituation of the light-startle response (LSR) of orange head cockroaches (Eublaberus posticus): Effects of acclimation, stimulus duration, presence of food, and intertrial interval. Insects, 12(4), 1-15. https://doi.org/10.3390/insects12040339

Operant Thermoregulation in Snakes

This project was a collaboration between myself, Dr. Aaron Place, Dr. David Craig, and Dr. Charles Abramson. Aaron Place and I both have a long interest in reptile behavior and Aaron suggested we explore operant conditioning in rattlesnakes. His idea was not to use food or water as a reinforcer, but instead use access to a cool temperature in a hot apparatus as a reinforcer. This method relies on snakes' natural tendency to seek cool places when hot, or warm places when cold. Our rattlesnakes learned to press a lever to reduce temperature in a hot apparatus. You can see a video below. Although rattlesnakes are interesting subjects, especially due to their thermal perception. I would like to move to a species that is a little easier to work with. For more information see:

Place, A. J., Varnon, C. A., Craig, D. P. A., & Abramson, C. I. (2017). Exploratory investigations in operant thermoregulation in western diamond-backed rattlesnakes (Crotalus atrox). In M. J. Dreslik, W. K. Hayes, S. J. Beaupre, & S. P. Mackessy (Eds.), The Biology of Rattlesnakes (pp. 213-227). Rodeo, NM: ECO Herpetological Publishing and Distribution.

We used an operant conditioning procedure to investigate the ability of western diamondback rattlesnakes (Crotalus atrox) and timber rattlesnakes (C. horridus) to learn to thermoregulate through an arbitrary behavior, a lever-press. Our rattlsnakes appear to be capable of learning through operant conditioning with reduction of temperature in a hot environment functioning as a reinforcer.