APOE and Alzheimer disease: Decreased functional connectivity between areas of the DMN has been demonstrated in cognitively healthy individuals with increased amyloid deposition (Hedden et al., 2009; Sheline et al., 2010), a family history of AD (Wang et al., 2012a), and presence of the APOE ε4 allele (Sheline et al., 2010; Wang et al., 2015; Liang et al., 2017).