Current approaches to the early detection of Alzheimer’s disease (AD) rely upon classifying individuals as “positive” or “negative” for biomarkers related to the core pathology of beta-amyloid (Aβ). However, the accumulation of Aβ begins slowly, years before biomarkers become abnormal. We used longitudinal [¹¹C] Pittsburgh Compound B (PIB) PET and neuropsychological assessment to investigate the earliest changes in AD pathology and how it affects memory in cognitively normal older humans. {read more here}