“…At the global whole-brain level, some neurobiologically meaningful graph-theoretic properties have become important indicators for measuring brain functional networks, through which we can understand the altered network architecture in those carrying risk genotype, including a loss of small-world network ( Korthauer et al, 2018 ), a redistribution of hubs ( Wink et al, 2018 ), and a disrupted modular organization ( Li et al, 2019 ). However, there are currently few network measures based on graph theory have been studied in cognitively unimpaired elderly ( Seo et al, 2013 ; Luo et al, 2017 ; Pietzuch et al, 2019 ) and some of their results were reported as inconsistent ( Seo et al, 2013 ; Qiu et al, 2016 ; Luo et al, 2017 ). For instance, Wink et al (2018) found decreased centrality of DMN in APOE4+ comparing to non-carriers, while Wang et al (2017) didn’t find such genotype difference of centrality in normal elderly.…”