A method for simulating intracerebral potential fields: the cortical imaging technique.

Source localization techniques such as the dipole localization method (DLM) have been used to elucidate the neural origins of scalp-recorded potentials. The type of source assumed in such techniques is usually suggested by the distribution of voltage maximums and minimums in scalp topographical contour maps. Unfortunately, the physical layers between the neural generators and scalp recording sites tend to smear and attenuate the potential fields, making it impossible, in some cases, to distinguish between single and multiple sources or extended layers. In this report, a mathematical (noninvasive) technique is described for simulating the potential fields that could be recorded directly on the surface of the brain. Such "cortical" potential fields exhibit details that are not apparent in the scalp topography. In several recent publications, this cortical imaging technique (CIT) has been tested on artificial and experimental data. After describing these results, some possible applications of CIT to clinical data will be presented.