Modeling heart beat dynamics and fMRI signals during carotid stimulation by neck suction

Central autonomic control on the cardiovascular system has been widely investigated in the last decades. More recently, with the advent of brain imaging techniques, considerable effort is being spent on defining the role of specific brain areas, and their dynamic network, acting on autonomic efferents. A way to assess autonomic modulation is offered by carotid stimulation. In this work, we propose a methodology to investigate autonomic control in carotid stimulation experiments using heartbeat series in combination with fMRI imaging. We modeled cardiovascular signals using the point process model, and processed fMRI data in order to estimate independent components of correlated information. Using cross-correlation and surrogate analysis, we assessed the responsiveness of subjects to neck suction stimuli and identified stimulus-related fMRI independent components.