Dielectric Tissue and Material Properties

Unless stated otherwise, the tissues in the anatomical head model were considered homogeneous and isotropic and their electric conductivity values were assigned according to the IT'IS Low Frequency (LF) Conductivity Database V4.1 [4]. For some precomputed models, the anisotropy of brain tissues is considered by using tensorial rather than scalar distributions of conductivity σ, as reflected in the model name. This is achieved by mapping diffusion tensor imaging data (from the same subjects imaged to generate the anatomical models) to tensorial σ maps.

As all electrodes were treated as boundary conditions (see Boundary Conditions), no material properties had to be assigned.