Nicholas Heroux

“Cognitive Effects of Proton Irradiation at Differing Energy Levels”

Nicholas Heroux

During exploratory class missions outside the magnetic field of the Earth, astronauts will be exposed to various forms of radiation including solar particle events (SPE) which are predominantly composed of protons. As such it is important to characterize the effects of exposure to proton radiation on cognitive performance. Previous research indicates that exposure to high energy protons (1000 MeV/n) may disrupt cognitive performance. Research also suggests that the relative biological effectiveness (RBE) of the different components of space radiation may vary as a function of particle energy. Since the majority of proton radiation emitted from SPEs is low energy it is necessary to determine whether there are similar differences in effectiveness as a function of proton energy. A series of behavioral studies were conducted to characterize the role of particle energy in the disruptions of cognitive performance seen in proton irradiation. In the initial experiments male Sprague-Dawley rats were exposed to 1000 MeV/n protons at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL). After irradiation the rats were shipped to UMBC and tested on a series of behavioral tests: novel object recognition, spatial recognition memory, elevated plus maze, and operant responding on an ascending fixed-ratio schedule. Cognitive performance on the behavioral tasks was variably disrupted in the experiments using rats exposed to 1000 MeV/n protons at the NSRL. The final study in the series compared the effects of different particle energies (1000 MeV/n and 150 MeV/n) on cognitive performance. Although the results of this experiment were not consistent with previous findings, there were no differences in performance as function of proton particle energy. As such, the possible risk of a performance deficit resulting from exposure to protons cannot be reliably estimated.

Acknowledgements: NASA Grants NNJ06HD93G, NNX08AM66G, NNX13AB73G.

How did you find your mentor for year research project?
I originally met my mentor by going to my advisor in the psychology department and asking about what research labs the department had to offer. After hearing that the psychology department had an animal behavior lab, I researched my mentor more in-depth by reading some of his research articles. I worked in his lab for one year before I approached him about doing an independent honors thesis, and because of the expensive nature of radiation research he already had a project in mind. I worked on and developed this project for about a semester before I applied for an Undergraduate Research Award.

How did you know this was the project you wanted to do?
Due to the expensive nature of radiation research I had very little choice on the topic of the project for my honors thesis (and thus the URA program). After working on the project for about a semester I designed and implemented several new behavioral experiments and really felt confident enough in my skills to take complete ownership. While the topic was narrow in scope, I had quite a bit of freedom in designing and implementing different behavioral experimental protocols and in analyzing and interpreting the data.

Is this your first independent research project?
This is my first large independent project – I think there is a large difference between being a research assistant with a lot of responsibility on a project and truly taking ownership and leadership of a project. There are so many factors to think about when designing and implementing research studies, and it has been and continues to be such invaluable experience.

Do you get course credit for this work?
I receive PSYC 498/499H credit for this work through the psychology departmental honors program (independent honors thesis). In the beginning stages I also received research practicum credit (independent reading/psychology research).

How did you hear about the Undergraduate Research Award (URA) program?
I heard about the URA program by getting a few emails via the myUMBC Undergraduate Research group. They post a lot of different research opportunities through their group and URA is just one great program of many.

What academic background did you have before you applied for the URA?
I had about two years of experience in animal behavior through two different labs (one year as a research assistant in my mentor’s lab, and one year being a research assistant at a lab at Johns Hopkins). Barring these two experiences I don’t think I would have felt confident enough to do an independent project – I needed to get direct experience in the field first. I was able to bring to my work at UMBC a few new behavioral experiments that I learned at my other lab.

Was the URA application difficult to do?
The application was not very difficult to do – in fact I believe it helped me clarify my goals and direction (much like writing an academic CV will do). The application process helped me to see where I am at and where I’d like to be, and the application allowed practice in a very important skill: proposing research.

What else are you involved in on campus?
I am involved in the Supplemental Instruction program in the learning resources center (I have been a math/chemistry SI leader for about two years and currently help lead training sessions occasionally as well). I am also a tutor and peer mentor in the Learning Resources Center and am working towards my master-level CLRA tutor certification (which is also a fantastic program to get involved in).

What is your advice to other students about getting involved in research?
Get involved as early as possible. Don’t let your self-doubts stop you from applying to research labs. Research labs don’t expect you to have a ton of relevant experience before entering; much of the training is done on the job (so it only hurts to wait). Talk to your peers and professors!

What are your career goals?
I am applying to Ph.D. programs in both Neuroscience and Behavioral Neuroscience with a focus on the neural mechanisms of animal behavior and learning. I want to be a researcher in academia.

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