The sensitivity of the EEG and MEG inverse solution to anisotropic conductivity – a whole human head simulation study

Abstract

Introduction Although it was demonstrated decades ago that the electrical conductivity of white matter tissue is anisotropic [1], this information is often neglected in EEG/MEG source localization studies using realistic head models. On the other hand, modeling methods like FEM [2] are able to include anisotropic conductivity. One reason for omitting this information may be the lack of a non-invasive method, capable to map spatially resolved anisotropic conductivity to incorporate this information in a realistic head model. Another reason may be that the benefit of including anisotropy information is not always obvious. This study aims to evaluate the sensitivity of the EEG/MEG inverse solution by neglecting white matter anisotropy for almost all possible cortical positions in gray matter in a whole-head high-resolution human FEM simulation study.