Electronic Theses and Dissertations

Date of Award


Document Type


Degree Name

Ph.D. in Health and Kinesiology

First Advisor

Minsoo Kang

Second Advisor

Paul Loprinzi


University of Mississippi

Relational Format



Recent research indicates that vigorous-intensity exercise concurrent with a prefrontal cortex (PFC)-dependent cognitive task can temporarily deactivate the PFC, leading to impaired cognition. Shifting attentional focus from a cognitive task to exercise or vice versa during exercise may also affect cognitive performance. However, the underlying mechanisms of this effect remain unclear. Therefore, this dissertation aimed to evaluate whether changes in attention and PFC oxygenation mediate cognitive impairment during vigorous-intensity exercise. Seventy-five young healthy adults (37 males, 38 females; 20.3 ± 1.6 years) completed three visits. The initial visit consisted of a max cycle test to measure VO2max via indirect calorimetry. In the other two visits, participants completed an Exercise condition, involving cycling at a high-intensity (≥ ventilatory threshold, VT) for about 15 minutes while completing Stroop tasks (Naming, Inhibition, and Switch tasks) four times at different intensities of cycling (baseline, moderate-, vigorous-intensity, post-exercise). The other visit involved an Active Control condition, in which participants followed the same experimental protocols as the Exercise condition, except cycled at a low-intensity (< VT). Attention and PFC tissue saturation index were assessed using a self-report associative-dissociative scale and functional near-infrared spectroscopy, respectively. Results showed that during vigorous-intensity exercise, cognitive accuracy decreased for Inhibition and Switch tasks, while reaction times were generally faster compared to baseline. Mediation analyses did not provide evidence supporting attention and PFC oxygenation as mediators of cognitive impairment during vigorous-intensity exercise. Future research on this topic could benefit by exploring the potential role of neurotransmitters as alternative mediators.

Available for download on Saturday, September 13, 2025