Methods and apparatuses for estimating activation of cerebral cortical sources from scalp site measurements of electroencephalograms (EEG) from a human subject are provided. In an exemplary embodiment, a method comprises: specifying cortical neural sources within the brain of the subject simulating activation potentials for the specified cortical neural sources projecting the simulated cortical neural source voltage activations to scalp site measurements locations for the subject simulating scalp voltage potentials for one or more extra-cranial sources outside the brain constructing simulated scalp site voltage potentials from the projected simulated modeled cortical neural source voltage activations and the simulated extra-cranial scalp voltage potentials comparing the simulated scalp site voltage potentials and the electroencephalograms scalp site measurements for the subject and adjusting parameters for simulating the cortical neural source voltage activations until the simulated scalp site voltage potentials generally correspond to the electroencephalograms scalp site measurements based on the comparison.
