Co-recording of EEG and fMRI data: EEG artifact removal

The electroencephalogram (EEG) is a standard technique to record and study the brain activity with a high temporal resolution (ms). BOLD fMRI (Blood Oxygenation Level Dependent functional Magnetic Resonance Imaging) is a non-invasive imaging method that allows the localization of activated brain regions with a high spatial resolution (mm). The co-recording of these two complementary modalities can give new insights into how the brain functions. However, the interaction between the strong electromagnetic field (3T) of the MR scanner and the currents recorded by the electrodes placed on the scalp generates artifacts that obscure the EEG and diminish its readability. With this work we aim at comparing two techniques, namely the Optimal Basis Set (OBS), based on Principal Component Analysis, and the Average Artifact Subtraction (AAS), both of them relying on the accurate detection of the pulse artifact. We will investigate the effect of a random time delay on this detection using simulated and real data. Keywords—EEG, fMRI, PCA