Estimation of Directed Effective Connectivity from fMRI Functional Connectivity Hints at Asymmetries of Cortical Connectome
Fig 8
Robustness of estimated C and Σ from FC with different time shifts τest.
A Match between C for τest = 4 s (x-axis) and C for τest = 2, 6 and 8 s (y-axis). Each plotted point corresponds to an EC connection and the black line indicates a perfect match. B Same as B for the EC estimated for τest = 0 on the y-axis. C Similar plot to A for the diagonal elements of the estimated noise matrix Σ. D Similar plot to B for the EC estimated using the direct method. E Agreement as measured by the Pearson correlation coefficient between the pairs of EC and Σ plotted in B and D for the LO (red), heuristic (purple) and direct (cyan) methods. The green error bar on the left represents the same between EC with τest = 0 and the four τest > 0. F Comparison of the models tuned with LO using different time shifts. For each model C obtained with τest from 0 to 6 s, the curve represents the Qτ error for all τmod on the x-axis.