During my undergraduate career at Washington and Lee University, I completed four separate semesters of neuroscience research credit for which I assisted a W&L cognitive and behavioral science professor, Dr. Brindle, in Institutional Review Board (IRB)-Certified research. As a prerequisite to work in the lab, I completed CITI Ethics training to be certified in human research ethics before completing any hands-on research and data collection. In what is known as the Jeffress Study, my colleagues and I measured the function of the baroreflex at rest, during stress (mental exercise), and during physical exercise. The mental stress task was the PASAT (Paced Auditory Serial Addition Test) while the physical exercise included riding a stationary exercise bike, and both were performed under controlled conditions. Dr. Brindle describes the baroreflex as “a physiological mechanism that buffers short-term changes in blood pressure,” causing heart rate to decrease when blood pressure is raised in the body by the vasodilation of arteries. Vasoconstriction of arteries, on the other hand, occurs when blood pressure in the body decreases, presenting a need for increased heart rate. 

Throughout the four semesters I spent in Dr. Brindle’s lab, my colleagues and I collected clean, usable data on about 91 out of a total of 134 participants from the Jeffress Study. The Finometer (used to measure blood pressure) broke toward the beginning portion of the study, so some data is missing as the tool required repair in the Netherlands. Even with the lack of some potential data, Dr. Brindle reported the collected dataset to be one of the largest to have baroreflex data in two mental stress tasks and exercise. The data collected from 2021-2022 will allow for the measurement of baroreflex effectiveness as well as its ability to change heart rate for combating blood pressure changes. Seemingly countless research questions can be asked with the baroreflex dataset, but a couple of key topics include the relationship between baroreflex function and adverse childhood experiences (ACEs) and the habituation of the baroreflex enduring multiple stress exposures. The research question I focused on most during my time in the lab was baroreflex function relative to cardiometabolic uncoupling during stress. Our body has a metabolic need for higher blood pressure and heart rate during physical exercise as our muscles need more blood for more oxygen. However, there is no metabolic need for more oxygen during mental stress, yet the same response is seen.

I finished my time in Dr. Brindle’s lab before any literature was completed on the Jeffress Study, but the baroreflex showed a substantially clear trend relative to both mental and physical stress. The baroreflex function had a direct relation to physical stress, decreasing in activity as physical stress intensity increased. The baroreflex also decreased in function during the PASAT which, in turn, supports the belief that the baroreflex plays a role in cardiometabolic uncoupling during both physical and mental stress.