Correlates of recognition memory performance in amnestic mild cognitive impairment

Determining whether the etiology of amnestic Mild Cognitive Impairment (aMCI) is Alzheimer's disease (AD) is challenging. Recognition memory (RM) performance could be helpful in identifying individuals with cognitive patterns indicative of underlying AD. In order to better identify such patterns, we examined RM discriminability in aMCI and its associations with nonmemory cognitive domains impaired in AD.

Participants were 97 individuals diagnosed with aMCI (M_age = 74.48 years) who underwent comprehensive neuropsychological evaluation. Zero-order correlations and hierarchical linear regression analyses were conducted to determine associations between discriminability on the HVLT-R and specific tasks within the domains of executive function (EF) and language, controlling for age and education. Logistic regression was conducted to determine whether performance on individual tasks was predictive of group membership defined as impaired or unimpaired on RM performance.

While 100% of the aMCI group showed impaired delayed recall on a word list, we found that 69% were impaired on RM discriminability, while 31% were not. Discriminability impairment groups did not differ on demographics or global cognition. For the entire aMCI group, performance in the language domain and, specifically, on a confrontation naming task significantly predicted RM discriminability. Confrontation naming was predictive of RM impairment group membership.

Our results demonstrate individuals with aMCI are heterogeneous and show variability in RM discriminability. RM performance was associated with measures of language, elucidating patterns of cognition potentially marking those more likely to progress to AD. Future studies need to address this finding in a longitudinal sample.