Fig 4. Network efficiency and cost.

We estimate the global network efficiency, the network cost, and the global network efficiency per cost for threshold values r_c. The datasets and the method to obtain the topological network structure are same to the case of Fig 3. A Network efficiency and the normalized network cost. The global network efficiency E is defined as the average of 1/L_ij, $E=\frac{1}{N(N-1)}{\sum }_{i\ne j}1/L_{ij}$ and the network cost is estimated with the total number of connections, ∑_{i ≠ j} a_ij. The global network cost is calculated with R-package brainwaver [11]. The network cost is normalized with dividing by its maximum value Cost → Cost/Max(Cost). B Network efficiency per cost. We show the value of E/Cost.