Influence of conductivity tensors in the finite element model of the head on the forward solution of EEG

The influence of conductivity tensor on the forward solution of electroencephalography (EEG) was assessed in the 2D head models of a human subject. The conductivity tensors of the different regions of the head were estimated from the diffusion tensor images by scaling the mean trace values to the published conductivity values. The anisotropic conductivity model was compared with the isotropic conductivity model in terms of the difference between the scalp potentials. The differences were measured by the cross correlation (CC) and the relative error (RE) between two models. The results with 252 individual dipole source show the CC is 0.96 and the RE is 31.24%. Although the CC is high, the large RE indicates that there is a significant amount of asymmetrical magnitude change on the scalp potential by the conductivity tensor. It indicates that the influence will also affect the inverse solutions of localizing the current dipole source