MAPT and Alzheimer disease: The abnormal local efficiency in typical Alzheimer’s disease also appears to be more extensive on the left, as has been noted before (Long et al., 2013), but such laterality effects should be viewed with caution, without inferring unilateral pathology: indeed by the stage of clinically diagnosed, symptomatic Alzheimer’s disease, both amyloid and tau pathologies are likely to be bilateral and widespread (Jagust, 2016; Ossenkoppele et al., 2016; Passamonti et al., 2017).