Kevin Murphy1, James Coulson1,2, Ashley D. Harris1, Marija Fjodorova1, Richard G. Wise1
1CUBRIC, School of Psychology, Cardiff University, Cardiff, Wales, United Kingdom; 2Wales Heart Research Institute, Cardiff University, Cardiff, Wales, United Kingdom
Dynamic changes in both blood pressure and arterial CO2 concentration lead to variations in the BOLD signal. Fluctuations in arterial blood pressure are controlled by the sympathetic nervous system through changes in arterial stiffness. Pulse wave velocity (PWV) alters with arterial stiffness and can be used as a surrogate measure of sympathetic activity. In this study, significant variance in resting state BOLD signals was explained by simultaneously recorded PWV traces. A lack of delay between the two signals suggests that the related BOLD fluctuations are associated with flow changes arising from dynamic variations in blood pressure.