The influence of surface deformations on electroencephalographic recordings

The precise identification of neuronal currents via Electroencephalographic (EEG) recordings is an important aspect in clinical practice and strongly depends on the accuracy of the corresponding forward problem. In addition, the precision of the EEG forward model is closely connected to the existence of a volume conductor model as realistic as possible. In this paper, the impact of geometric variations of the head on the measured electric potential has been studied by means of a homogeneous spherical conductor. In the case where the activated region is situated in the vicinity of the deformation, the calculated potential values show a slight increase. On the other hand, for neuronal currents away from the deformation no influence upon the surface electric measurements is observed.