The cognitively unimpaired stage of Alzheimer’s disease (AD) is quite long in duration, but the interval varies widely from person to person. This talk will describe some of the brain and cognitive changes that we have observed from over a decade of biomarker imaging within the Wisconsin Registry for Alzheimer’s Prevention (WRAP) and related studies. The talk will give an overview of the WRAP study including its approach to measuring cognition, and describe the approaches to biomarker imaging we and others use to characterize AD proteinopathy. I’ll describe how we have derived temporal information from biomarker imaging such that age of onset of AD proteinopathy and disease duration can be estimated. I’ll also describe some of the factors that influence age of onset and duration of the pre-symptomatic stage of AD duration of the pre-symptomatic stage of AD.