In the clinical stages of mild cognitive impairment (MCI) and Alzheimer’s disease dementia, studies combining magnetoencephalography (MEG) and PET have demonstrated a slowing of neurophysiological signalling in response to the cortical accumulation of amyloid-β and phosphorylated tau proteins.2,3 Compared to healthy older adults, such slowing is indicated by increased low-frequency activity in the delta (2–4 Hz) and theta (4–8 Hz) bands, alongside decreased signalling in the faster alpha (8–12 Hz) and beta (15–30 Hz) bands, in the brains of individuals with Alzheimer’s disease. Here, MAPT is linked to Alzheimer disease.