Title:

Estimation of zero-lag cortical functional connectivity from EEG and MEG data

Abstract:

Electro-encephalography (EEC) and magnetoencephalography (MEG) non-invasively measure human cortical activity through the electric potentials on the scalp (EEG) and magnetic fields outside the head (MEG) that are induced by the currents in active cortical tissue. Interpretation of the EEG/MEG sensor signals in terms of cortical current densities is, however, limited by the spatial low-pass character of the EEG/MEG forward models, which give rise to severely ill-posed (linear) inverse problems. One of the open problems is how to reconstruct cortical functional connectivity as measured by the pair-wise zero-lag correlation matrix between cortical regions. In this talk I will give an introduction to this problem and describe recent efforts to characterize and de-bias standard estimators.