Our study focused on EC-dependent path integration since impairments in this function correlate strongly with a number of risk factors for Alzheimer’s disease such as the Cardiovascular Risk Factors, Aging and Dementia Study risk score,21 the apolipoprotein E ε4 allele17,20 and MCI in which reduced EC volumes are found.16 This evidence concerns the gene APOE and early-onset autosomal dominant Alzheimer disease.