Undergraduate Honors Theses

Thesis Defended

Spring 2019

Document Type


Type of Thesis

Departmental Honors


Psychology & Neuroscience

First Advisor

Marie Banich

Second Advisor

Heidi Day

Third Advisor

Lee Niswander

Fourth Advisor

David Caha


Determining reliable measures that show how the brain can regulate the body and its physiological states could offer insight into how mental health and wellbeing is related to physiology and self-regulation. This study investigates how heart rate variability (HRV) at rest (rHRV), a measure of autonomic nervous system activity according to several studies (Thayer 2009, Colzato 2017, Shaffer & Ginsberg, 2017), relates to neurotransmitter levels in the prefrontal cortex (PFC), cognitive control over emotional material, and individual traits involved in psychopathology. Resting heart rate (HR) measures were taken via pulse rate measurements in an MRI scanner, and processed into rHRV. Prior research has suggested that increased heart rate variability is associated with a) better emotional regulation and b) individual differences in GABAergic function. We investigated these relationships in a novel manner by examining whether GABAergic function of the prefrontal cortex, which is known to be involved in emotion regulation, is associated with rHRV. No significant correlations were found between rHRV and any of the main measures: prefrontal GABA concentration, emotional regulation or measures related to psychopathology. Potential reasons for these null findings include a) that the GABA concentrations were obtained 20-24 months earlier, b) that the method used to assess rHRV is not as robust as standard measures which are difficult to implement in the magnet, c) the size of our current sample is small and hence may be underpowered to detect such relationships.