3D Barycentric Interpolation Method for Animal Brainmapping

The evaluation of electroencephalographic (EEG) signals is very crucial for human studies. Mostly there are animal recordings of EEG used for further research as well. One of the often used quantitative EEG methods for EEG analysis is topographical mapping. The barycentric interpolation method for 3D animal brain-mapping was implemented and tested. The 3D spline and spherical spline interpolation methods were used for comparison purpose. The surrogate data and real EEG recording were used for the interpolation methods testing. The Root Mean Square Error (RMSE) and significant probability mapping via Fisher non-parametric permutation test were used for evaluation. The RMSE of surrogate data was 0.070 for 3D spline, 0.594 for spherical spline and 0.321 for 3D barycentric interpolation method. The RMSE of the real EEG recordings nearby the electrodes was 0.1848 for 3D spline, 1.1027 for spherical spline and 0.0001 for 3D barycentric interpolation method. The 3D barycentric method differs from the 3D spline interpolation method in the large area on 0.001 alpha level based on significant probability mapping. The non-significant parts are only in the nearby electrode area. The 3D spline interpolation method gives the best results based on RMSE and significant probability testing.