Figure 2.

Small-world properties of the metabolic brain networks. The images indicate the changes in $\gamma ={\text{ C}}_{\text{p}}^{\text{real}}/{\text{C}}_{\text{p}}^{\text{random}},\text{λ}={\text{ L}}_{\text{p}}^{\text{real}}/{\text{L}}_{\text{p}}^{\text{random}}$ and σ = γ/λ in normal control (NC), mild cognitive impairment (MCI), and Alzheimer’s disease (AD) groups (sparsity ranging 18%-40%).