Voxel preference profile-specific whole brain functional connectivity

Starting from the single voxel whole brain functional connectivity profiles that were used to compute the connectivity profile similarity matrix (see subsection “Resting state functional connectivity profiles”, above), a statistical assessment was made of the task preference-specific functional connectivity profiles across participants. For each participant, each of the two IFS1 ROIs, the single voxel functional connectivity maps were average for voxels of the same mono-task preference type. This resulted in three FC maps per ROI and per participant. These average FC maps were Fisher-Z transformed and smoothed with a 6 mm FWHM Gaussian kernel to compensate for interindividual anatomical variation. These maps were used in a second level repeated measures GLM analysis with two ROIs (left and right) and three task preference types (Eriksen, Backmatching and Switching) as the independent factors. A general preference type-specific functional connectivity map was generated by a contrast that combined the left and right data into a single statistical image of voxels with an association strength that significantly differed from zero. The statistical image was corrected for multiple comparisons using a whole brain FDR-corrected significance level of 0.05.