APOE and dementia: Human neuroimaging studies have linked hippocampal hyperactivity to amyloid accumulation (Huijbers et al., 2015), apolipoprotein E4 (APOE4; Bookheimer et al., 2000; Johnson et al., 2006; Filippini et al., 2011; Tran et al., 2017) and progression to dementia (Huijbers et al., 2015).