Figure 3. A hypothetical model of awareness of memory across the preclinical and prodromal stages of AD.

The model depicts cognitive performance (y-axis), awareness of memory function (color coded) and their relationship to disease pathology and clinical stages (x-axis) of Alzheimer’s disease (AD). After a phase of stable cognitive performance in the presence of increasing pathology, subtle decline of cognitive performance occurs at which point the individual becomes increasingly aware of a change in memory function (hypernosognosia: orange color). Of note, hypernosognosia might be present in individuals without increased neurodegenerative pathology which might represent the “worried well” population. As pathology increases and impairment of cognitive tests is documented clinically, the individuals self-report’s of memory impairment levels off and becomes less reliable (anosognosia; red color). Of note, we found that MCI patients without increased amyloid pathology had insight into their memory impairment. The model is based on cross-sectional data.