PSEN1 and Alzheimer disease: Compared with healthy aged controls, asymptomatic subjects at risk for AD, including presenilin-1 (PSEN1) C410Y and E280A carriers, show higher activation of the hippocampus and frontal and temporal cortices during associative memory encoding years before clinical symptoms (Bassett et al., 2006; Mondadori et al., 2006; Yassa et al., 2008; Reiman et al., 2012).