Functional imaging of the brain

Electroencephalography (EEG) and Magnetoencephalography (MEG) measure brain activity passively, from outside the head. Compared to other brain imaging modalities, EEG and MEG provide the finest time-resolution, of the order of the brain's. The interpretation of EEG and MEG data in terms of spatial localization is however intricate, because it requires to solve an ill-posed inverse problem.

For a layman's introduction to this field, please consult Interstices (in French). A movie (also in French) presents EEG and MEG (shot at Odyssée and at La Timone hospital, 2007).