Fig. 2

Distribution of amnestic mild cognitive impairment subgroups. aMCI amnestic mild cognitive impairment, Both-aMCI aMCI with both verbal and visual memory impairment, Early-stage aMCI aMCI with delayed recall item scores between 1.0–1.5 SD below age- and education-matched norms on both verbal and visual memory tests, Late-stage aMCI aMCI with delayed recall item scores 1.5 SD below age- and education-matched norms on either verbal or visual memory tests, Multiple-aMCI aMCI with memory and dysfunction affecting other cognitive domains, Single-aMCI aMCI with memory deficit alone, Verbal-aMCI aMCI with predominant verbal memory impairment, Visual-aMCI aMCI with predominant visual memory impairment