THE RELATION BETWEEN ALPHA BAND POWER, HEART RATE AND FMRI

The brain's resting state is studied with the analysis of co-registered fMRI/EEG/ECG. In particular, it was investigated whether spontaneous heart rate fluctuations are correlated to fMRI-signals. This might be the case because of a direct hemodynamic coupling, or due to an indirect coupling between heart rate and alpha band power, which are both hall marks of the resting state. It was found that (1) higher alpha power coincides with a higher heart rate, (2) heart rate regressors are in many subjects strongly coupled to fMRI, and (3) inclusion of heart rate confounders hardly affects earlier reported correlations between alpha band and fMRI.