Efficiency and Cost of Economical Brain Functional Networks
Figure 2
Economical Properties of Human Brain Functional Networks
Efficiency (y-axis) as a function of cost (x-axis) for two individual brain networks: a young subject following placebo (left panel) and an older subject following placebo (right panel). For both subjects, local efficiency (red lines) and global efficiency (green lines) increase monotonically with cost; and cost efficiency (the difference between global efficiency and cost; blue lines) has its maximum value when 0.2 ≤ K ≤ 0.4. The low-cost threshold, K ∼ 0.1, associated with the sparse networks reported in Figures 3 and 5, is shown as a black vertical line in each graph.