Correlated Slow Fluctuations in Respiration, EEG, and BOLD FMRI: What Is the Origin of Physiological Noise?

Han Yuan¹, Vadim Zotev¹, Raquel Phillips¹, Jerzy Bodurka¹

We investigated the relationship between the respiration, alpha-band-limited EEG power, and BOLD fMRI from simultaneous recordings in human subjects and have found significant correlation between slow temporal fluctuations of these three sources of signals. In particular, the correlation between respiration and EEG is much stronger in closed-eye resting than in open-eye resting, and is consistently observed from recordings inside and outside scanner. Results suggest that respiration fluctuations reflect and are linked to the underlying brain electrophysiological activity.