Study of the mesh dependence.

(A-D) Sixty simulations of spreading seizure in the noise-free variant of the model were performed on the standard triangulation (described in the main text) and on refined triangulation of the cortex, obtained by splitting every existing triangle into four. The simulation parameters were chosen randomly as in the main text, but were kept between the simulations on standard and fine triangulations, so that the results are directly comparable. The background noise was however different between the simulations on standard and fine triangulation. (A) The activity of the simulated SEEG signals were classified into non-seizing (NSZ), seizing but not TAA (SZ), and TAA (see Methods). (B) For the signals classified as TAA in both standard and fine simulations, the determined time of TAA onset is compared. Perfect fit would lie on the diagonal marked by black dashed line. (C) Same as B but for the determined duration of TAA pattern. (D) Histogram of the differences of the TAA onset times and durations from panels B and C. The range is clipped for visualization, amount of clipped values is shown in the inset text. (E-F) To assess the influence of the background noise, second set of simulations on the standard triangulation was performed. The parameters of the simulations were again kept the same as in the first set, only with the background noise changed. Panels are equivalent to panels A-D, showing the fit between the two sets of simulations on standard triangulations. Comparison between the first and second row of the figure indicates that the differences between the simulations on standard and fine triangulations are caused mainly by the stochastic background noise, since they are present also for the simulations on the same triangulations. The level of mesh refinement thus does not introduce differences of higher order of magnitude.

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