Simultaneous EEG-fMRI recordings (EEG-fMRI)

Simultaneous EEG-fMRI recordings require the presence of MRI compatible EEG amplifiers and electrodes. EEG-fMRI allows for simultaneous acquisition of electrophysiology (EEG) and hemodynamic (fMRI) information. EEG-fMRI thus provides high spatial and temporal resolution with regard to anatomical localization and on-line signal registration. Because of the large artifacts generated in the EEG recording from the switching on-off of the MRI gradients, particular care has to be taken for artefact removal in the recordings. EEG-fMRI data are often analyzed using an independent component analysis (ICA) approach, which allows for single trial analysis of correlations between e.g. ERP and BOLD amplitudes.

The figure shows the EEG electrode placement on the scalp when the subject is placed in the MRI head coil. From Bergen fMRI Group, GE 3.T Signa MR scanner with NNL Inc. LED goggles, and BrainProducts EEG amplifiers.