(Tijms et al., 2014; van der Flier, Pijnenburg, Fox, & Scheltens, 2011) This decrease is in line with recent results from fMRI studies in healthy middle‐aged controls, where different levels of activity in V1 discriminate between controls with risk of AD who carry the APOE‐ε4 allele from those who do not (Rajah et al., 2017). Here, APOE is linked to Alzheimer disease.