Figure 7.

Group PEB results for the state-dependent effective connectivity. Group-level state-dependent effective connectivity matrices, and their connection maps were displayed for connectivity states S2, S4, and S5. A fixed-effects model (concatenating all DCMs for all children) was used for all the subjects (both ADHD-C and TDC) using PEB. The fixed-effect models for ADHD-C and TDC's spDCMs were hierarchically modeled with group common (average) (A) and group difference (B) design matrix using an additional PEB analysis step. We found none or few group differences in the effective connectivity at the states S2 and S4 while stronger self-inhibition was found in the ADHD-C compared with TDC in the state S5. The colors in the rectangular matrix represent the MAP for the connectivity from the column element to the row element. The diagonal term in the rectangular matrix should be interpreted after a transformation of −0.5 exp(A_ii), to constrain the diagonal term for the self-connectivity to be inhibitory. For clarity, diagonal elements are displayed with transformed values in the network diagram in the second row of (A). Effect sizes that survived a criterion of 95% posterior confidence are shown in numbers and rectangles.