Conductivity models for functional neuroimaging Electro-and magneto-encephalography provide measurements of brain activity at high time resolution. Their interpretation is intricate because they mix various sources of activity. This talk establishes the models required for extracting brain source activity from EEG and MEG data. To represent the geometry and conductivity of tissues, and compute the forward problems, boundary element methods have been developped and implemented in opensource software. This is of particular interest for multimodal validation of source localization results.