Overestimation of performance after a memory task in cognitively unimpaired individuals is related to lower cortical thickness in Alzheimer’s disease vulnerable regions and to executive decline, particularly in men.

Abstract

AbstractBackgroundLow awareness of cognitive decline is a common feature in Alzheimer’s disease (AD) dementia, and it relates to higher risk of progression in individuals with Mild Cognitive Impairment. Previous research suggests that, in cognitively unimpaired individuals, it has prognostic value and is related to AD biomarkers. We aimed at exploring the associations between the ability to judge performance after a memory task and demographic, clinical (cognitive complaints), structural neuroimaging, cognitive and amyloid status variables in cognitively unimpaired individuals.MethodsWe analyzed data from 225 ALFA+ study participants (mean[SD] age = 68.9[4.9], 63.6% female). We defined a discrepancy score between objective and subjective memory measures by subtracting the self‐ratings of performance in the delayed recall of the Memory Binding Test (range 0–100) from the percentage of words actually recalled. Structural MRI (AD signature cortical thickness), amyloid (PET visual read), and Subjective Cognitive Decline (SCD) status measures were available. We classified individuals as decliners vs non decliners (change >‐0.5 z‐score after 3 years) using executive and memory composites. Linear models with the discrepancy score as dependent variable and age, sex, education, AD signature, amyloid and SCD status as predictors, and with decline/non decline in executive and memory composites as predictors, were constructed.ResultsMales overestimate their memory performance more than females (p = 0.003, Figure 1). Lower cortical thickness in the AD signature was also related to overestimation (p = 0.035, Table 1). Age, education, amyloid and SCD were not significant predictors and did not interact with sex or AD signature. Decline in the executive composite was related to overestimation of performance (p = 0.048), being this association driven by men (men p = 0.032, women p = 0.403, Figure 2). We did not find associations with decline in memory performance.ConclusionsOur results suggest that, in cognitively unimpaired individuals, the overestimation of objective memory performance relates to lower cortical thickness in AD vulnerable regions and to a subtle decline in executive abilities. Men seem to overestimate their ability more than women, particularly those that have decline in executive scores. Future research to define the value of altered self‐judgment of cognitive ability in presymptomatic stages of AD and its relationship with SCD is granted.