MEG/EEG error bounds for a dipole source with a realistic head model

Magnetoencephalography (MEG) and electroencephalography (EEG) are non-invasive methods for studying human brain activity, with a time resolution of milliseconds. Current dipoles are the most common model describing sources of brain activity. We show how to compute error bounds when estimating the dipole source parameters for a realistic head model, using measurements of electric potential (EEG), magnetic field (MEG) and their combination. The electric potentials and magnetic field components are obtained by discretizing the integral equations for the fields via the boundary element method (BEM) and a weighted residuals technique. This process requires an accurate representation of the surfaces separating the irregular head layers, as obtained from MR or CT imaging.