Combining Attentional Control and Semantic Memory Retrieval: A Sensitive Marker for Early Stage AD and AD-related Biomarkers in Healthy Older Adults

Abstract

Past studies have shown that measures of attentional control and semantic memory retrieval are sensitive markers of Alzheimer disease: AD). The present study examined the utility of combining measures of attentional control and semantic retrieval within a single task to discriminate healthy aging from early stage AD and show sensitivity to AD biomarkers in healthy control individuals. On each trial of the present task, participants viewed a category: e.g. “a unit of time”) and verified whether a subsequent target item was an exemplar of the category: “hour”) or not: “clock”). Importantly, the nonmembers of the category were associatively related: e.g., a “clock” is not “a unit of time”, but is highly related), and hence, placed a premium on attentional control systems to reject. Results indicated that accuracy to the foil items was the strongest discriminator between healthy aging and very mild AD. Furthermore, accuracy correlated significantly with AD biomarkers, including tau, p-tau, Aβ42 and PIB, in healthy control participants who are at increased risk for developing Alzheimer disease. Discussion focuses on the combined influence of attentional control with explicit retrieval from semantic memory as a marker of early stage AD as well as a sensitive correlate of established biomarkers for AD risk in healthy control participants