Combined EEG-fMRI recordings pose several challenges for data analysis. Several large artifacts need to be handled in order to successfully recover the brain-related EEG signals in the magnet. The largest one caused by the magnetic field can be handled effectively using established procedures. However, another one, the ballistocardiogram (or pulse) artifact, remains.
Rusiniak et al. compared different approaches to reduce the ballistocardiogram artifact in combined EEG-fMRI recordings and found that using surrogate source models to separate the artifact-related signals from brain signals had minimal distortion of the brain activity of interest. The surrogate method showed a significant improvement over previous established methods like OBS and BSS in particular for source localization. Click here!
The pipeline for EEG-fMRI analysis using the surrogate method is fully implemented in BESA Research. It is also documented on the BESA Wiki: Check out more here!