Indeed, although the effect sizes of our models suggest an adequate sample size for this study, reproducibility of brain–behaviour associations are particularly sensitive to the numerosity of the sample.81 Finally, here we did not control for genetic risk factors of pathology (e.g. ε4 allele of apolipoprotein E -APOE) nor did we consider the amyloid burden along the Alzheimer’s disease continuum, but rather amyloid burden was computed as a two level categorical variable, i.e. as a positive or negative status. The gene discussed is APOE; the disease is Alzheimer disease.