Fig. 3.

Functional connectivity is modulated by the level of cognitive efficiency. (A) Three levels of the fMRI data analysis stream build upon each other. The colored frames correspond with the more detailed depiction in Fig. S3. Based on the global connectivity between all voxel pairs, we calculated the correlation of all connections with cognitive efficiency across participants. This calculation resulted in a global modulation matrix in which each row (modulation profile) represented the increases and decreases of connectivity that occurred in association with the level of cognitive efficiency for a given voxel. We assessed the statistical significance of the modulation by permutation statistics (SI Materials and Methods and Fig. S3). To further investigate the effect, we calculated the similarity matrix of the identified modulation profiles (Fig. 4A) in subsequent analyses. This matrix represents the cross-correlations of all of the identified modulation profiles. (B) Cortical regions, which exhibit significant modulation by cognitive efficiency. The map has been thresholded at P = 0.05, one-tailed, FDR corrected.