HIGH-RESOLUTION EEG - A NEW MODEL-DEPENDENT SPATIAL DEBLURRING METHODUSING A REALISTICALLY-SHAPED MR-CONSTRUCTED SUBJECTS HEAD MODEL

This paper presents a new model-dependent method for the spatial deblu rring of scalp-recorded EEG potentials based on boundary-element and c ortical imaging techniques. This model-dependent spatial deblurring (M DSD) method used MR images for the reconstruction of the subject's hea d model, and a layer of 364 radially-oriented equivalent current dipol es as a source model. The validation of the MDSD method was performed on simulated potential distributions generated from equivalent dipoles oriented radially, obliquely, and tangentially to the head surface. F urthermore, this method was used to localize neocortical sources of hu man movement-related and somatosensory-evoked potentials. It was shown that the new MDSD method improved markedly the spatial resolution of the simulated surface potentials and scalp-recorded event-related pote ntials. The spatial information content of the scalp-recorded EEG pote ntials increased progressively by increasing the spatial sampling from 28 to 128 channels. These results indicate that the new method could be satisfactorily used for high resolution EEG studies. (C) 1997 Elsev ier Science Ireland Ltd.