PSEN1 and Alzheimer disease: Oscillatory slowing is an early neurophysiological hallmark of Alzheimer’s disease, which has been observed as early as the subjective cognitive decline stage of the disease.61 Increased relative theta power has moreover been reported in cognitively unimpaired carriers of APP and/or PSEN1 mutations.64 In contrast to these findings, Nakamura et al. 37 reported significantly higher pre-frontal alpha power in Aβ-positive cognitively unimpaired individuals and patients with prodromal Alzheimer’s disease compared with Aβ-negative individuals.