the graph G is computed as the ratio between NC and NL, SW = NC/NL. The network topology may be said to correspond to a “small world” if NC>1 and NL≈1 [38] or if SW>1 [45]. In addition to the conventional small-world parameters (C and L), more biologically sensible properties of the brain networks are the efficiency parameters (global efficiency [GE] and local efficiency [LE]), which measure the capability of the network with regard to information transmission at the global and local levels, respectively [35]. The global efficiency of the graph G can be computed as:where dij is the shortest path length between nodes i and j. The local efficiency of the graph G is defined as:where GE(Gi) is the global efficiency of Gi, the subgraph of the neighbors of node i.
