Figure 2.

The calculation of dHOFC. This schematic plot shows how dHOFC is calculated and how the amount of information is increased from LOFC network to dHOFC network. Pairwise static LOFC only generates a 264 × 264 matrix, representing the static low-order brain functional network. By performing the sliding-window based dynamic LOFC (dLOFC) calculation for each pair of brain regions (i.e., i and l, and j and k, respectively), two dLOFC time series are generated. A further correlation of these two time series produces dHOFC among the four regions: i, l, j, and k. The information is geometrically increased in its amount, when using dHOFC matrix rather than LOFC to represent a brain network.