Several studies have demonstrated an association between EEG characteristics of functional connectivity and the AD risk variant, ApoE E4+. Functional network disruption in patients with early AD carrying the ApoE E4 allele was characterized by decreased interhemispheric alpha2 connectivity between the frontal and parieto-temporal areas compared with noncarriers (Canuet et al., 2012). This evidence concerns the gene APOE and Alzheimer disease.