Cassidy Whitehead, a senior completing a double major in biochemistry and psychology, spent two months this past summer in Bloomington researching how cannabis affects and individual’s decision-making process.
The research project, “Cannabis Use and Decision-Making: A Focus on Delay Discounting,” in collaboration with of Sharlene Newman, professor of psychological and brain sciences and an associate vice provost for Undergraduate Education at Indiana University, and IU graduate student David Raymond.
Whitehead worked on the research project as a recipient of a Regional Campuses of Indiana University Presidential Summer Research Fellowship. She joined the project in June.
“They wanted to figure out if there were activation differences in the brain between the cannabis users and non-cannabis users,” Whitehead said. “They were specifically looking at an area called the mesolimbic pathway, and that deals a lot with decision making, risk taking, and things like that. They’ve used this to look at alcoholics and gambling to see how those types of things would be affected, and how cannabis use may affect this.”
According to the research project’s abstract, cannabis use has been shown to affect the neural circuitry involved in decision making, especially that of the mesolimbic dopamine system, a dopaminergic pathway vital to reward processing. Dysfunction of this circuitry can lead to the development and continuation of drug use, so it is imperative that its inner workings are understood. Previous studies have employed behavioral tasks such as the Balloon Analog Risk Task (BART) and delay discounting tasks to examine decision making in substance abuse populations with few examining cannabis users and even fewer examining brain activation measured with functional magnetic resonance imaging (fMRI).
“One of the tasks Cassidy worked on was a delayed discounting task, which is really designed to determine how well people can delay gratification, if they can wait for a larger reward or if they take the lower reward faster. There is some suggestion in the literature that shows users have problems with delay gratification, but there isn’t a lot on cannabis users.”
Newman explained the project used the fMRI data, providing the opportunity for Whitehead to analyze the data.
“She was a great student. She was very inquisitive and asked a lot of questions,” Newman said. “She learned how to do the analysis relatively fast so it was nice to have her in the lab. It was nice to have another perspective in lab. Most of the students in the lab are IU students, so having that different perspective was interesting. She also engaged in conversation about other studies that were taking place in the lab.”
The project evaluated 32 subjects ages 20 and over. Participants in the study choose between two monetary options with one choice providing immediate reward and the other providing an objectively larger delayed reward.
Whitehead would take the data after subjects completed the fMRI, and compiled the imaging from the machine then produce an understandable image. “It (images) would have differences in activation in the brain,” she said. The research project provided Whitehead with an opportunity to enhance her skills, including how to use an fMRI, statistical parametric mapping, coding and Linux operating system.
“When we did the research, it showed that there was similar activation between the two groups,” Whitehead said. “However, the non-users showed greater activation in the anterior cingulate cortex and the lateral prefrontal cortex. Those were the only significant differences we found between the two, and it implies that there needs to be a lot more research about discernable differences between cannabis users and non-users.”
Newman will continue the research and using the data collected over the summer. She is interested in comparing how cannabis affects female users in particular, and how hormones interact with use and neurological functioning. The collected data is also being included in a manuscript.
Once the project was completed in July, Whitehead gave a poster presentation. She will also give the poster presentation this spring during IU East’s Student Research Day.
She is also expanding on the project for her Honors Program senior thesis. Whitehead is conducting background work to review current literature on the research and how the project relates to other studies. She will present on the thesis this spring as well.
Whitehead first heard about the fellowship from her academic advisors Marcus Bingham and Liz Ferris (now the associate director of the Office of Student Success), and both encouraged her to apply.
The option to choose a research project through the IUPUI or the IU campus to complete the fellowship. She chose Bloomington because she previously lived there for six years. “It had a homey feeling for me,” she said.
Whitehead graduated from Richmond High School. Her mother, Stephanie Whitehead, is an associate professor of criminal justice and the director of the Center for Faculty Development at IU East. Whitehead said she applied to several other colleges but chose IU East.
“At the end of the day, IU East was going to be the least expensive option, especially in terms of me being able to stay at home. The campus has everything I wanted including an advanced science degree. I was also really keen on smaller class sizes and getting to know my faculty.”
While at IU East, Whitehead has been active on campus. In addition to being in the Honors Program, she is a tutor with the Math and Science Center in the areas of biology, chemistry and physics. She has also tutored elementary to high school students through IU East’s Center for Service-Learning through Math Counts! She is the president of Circle K and was one of the student speakers featured at the Spirit of Philanthropy Luncheon in October. She is also a volunteer through Opening Minds through Art (OMA), a program that connects students with elders with dementia and fosters communication, self-worth and social interaction through art projects.
She chose to pursue a degree in biochemistry because science has always been an interest. She considered everything from veterinary medicine to nursing and more.
“I loved science from an early age,” Whitehead said. “There was nothing non-science that I ever wanted to do.”
Currently, Whitehead is working on a research project with Parul Khurana, associate professor of biology on self-regulated learning. She added the psychology degree provides her with the human aspect and look into human behaviors.
“Cassidy’s dedication as a student stems from her motivation to learn,” Khurana said. “These qualities also make her a great researcher. She spends time to learn about the topic she is working on, and makes a plan before jumping into the work. She has the right balance of enthusiasm and patience, which allows her to conduct experiments or analyze data quickly and efficiently.”
Khurana added she is excited to work with Whitehead on the research project.
“In our current project Cassidy is analyzing interviews and survey data to study how students regulate their learning in various circumstances. With her interest and background in biochemistry and psychology, Cassidy is uniquely qualified to examine different aspects of the study, such as biology education, and human motivation and behavior,” Khurana said.
Yu Kay Law, associate professor of chemistry, has worked with Whitehead as a student and as an SI Leader (supplemental instructor) for his general chemistry classes.
“Cassidy is one of the best students and SI leaders I’ve worked with,” Law said. “In class, she has always been one of the most diligent and completes all work well. She participates in class actively both in whole-class discussion and in group work, and it is clear that she ‘plays’ well with her classmates and studies hard out of class, and is not afraid to seek advice. As SI leader, she is excellent at helping students understand the topics and designing learning activities around how the class operates, thus helping her peers succeed.”
Whitehead is completing her degree programs at IU East and plans to graduate this May. She hopes to pursue a graduate degree in medicine or physician’s assistant program.