Realistic geometry Laplacian: a moderate spline estimation approach

A moderate scale approach of the realistic geometry spline Laplacian (MSL) for high-resolution EEG mapping was proposed. In this approach, firstly find the neighboring electrodes of one electrode on the scalp surface within a chosen radius, use their spatial coordinates and potentials to generate a regional spline interpolated potential distribution function, and then estimate the surface Laplacian of this electrode position using Laplacian differentiation operation. The effects of MSL and the global realistic geometry spline Laplacian (GSL) were compared by computer simulation studies using a realistic head model and by human visual evoked potential data. All the results show MSL can provide better results than that do by GSL.