Fig. 2

Functional connectivity networks are created by grouping voxels in the brain using parcellations: a voxels are grouped by anatomical regions from a predefined parcellation; b all the temporal signals in a region are summarised into a representative signal, and then the coactivation is calculated for each pair of regions; and c the coactivation values are formatted into a matrix that can be viewed as a network for analysis and interpretation. Uncertainties arise from this process regarding how well the parcellations fit each subject, heterogeneity in the temporal and spatial data, as well as the loss of spatial information in formatting as a matrix