Extracting cortical current dipoles from MEG recordings.

A novel way of using synthetic aperture magnetometry to extract local current dipoles is proposed. This method is used to extract the current-dipoles at multiple points in the cortex. It is shown that in this way the correlation between cortical points is lower and falls faster with distance when compared to the original MEG and other methods. Evoked auditory responses are well localized. They show higher signal to noise ratio and are more reproducible then the MEG evoked fields.