Memory consolidation in aging and MCI after 1 week.

Abstract

Objective To assess consolidation in amnestic mild cognitive (aMCI) impairment, controlling for differences in initial learning and using a protracted delay period for recall. Methods Fifteen individuals with MCI were compared to fifteen healthy older adult controls on a story learning task. Subjects were trained to criteria to equalize initial learning across subjects. Recall was tested at both the 30-minute typically used delay and a 1-week delay used to target consolidation. Results Using repeated measures ANOVAs adjusted for age, we found group × time point interactions across the entire task between the final trial and 30-minute delay, and again between the 30-minute and 1-week delay periods, with MCI having greater declines in recall as compared to controls. Significant group main effects were also found, with MCI recalling less than controls. Conclusion Consolidation was impaired in aMCI as compared to controls. Our findings indicate that MCI-related performance typically measured at 30 minutes underestimates MCI-associated memory deficits. This is the first study to isolate consolidation by controlling for initial learning differences and using a protracted delay period to target consolidation in an MCI sample.

Cross-species translation of the Morris maze for Alzheimer’s disease

“…For the trials were spaced to avoid the effects of hypothermia on performance. Spaced training enhances learning in healthy mice and humans (24,25) but likely increases the difficulty of the task for hAPP mice and MCI-AD patients due to forgetting between trials (26,27). Another possibility is species differences in incentive to complete the task.…”

Accelerated forgetting? An evaluation on the use of long-term forgetting rates in patients with memory problems

“…The long term forgetting rates of 15 MCI patients and 15 healthy controls were also examined by Walsh et al ( 2014 ), using a story recall task. In contrast to the study of Manes et al ( 2008 ), they matched initial acquisition by using an optimized learning procedure.…”

How do we get there? Effects of cognitive aging on route memory

“…In fact, performance in the route recall task differed between all three participant groups with the Young group showing best performance followed by the Old High MoCA group and then the Old Low MoCA group. While forgetting is rarely studied in the context of spatial cognition and navigation, it has been studied in other cognitive domains and accelerated forgetting has been associated with both healthy aging (Huppert & Kopelman, 1989 ) and with mild cognitive impairments (Geurts, van der Werf, & Kessels, 2015 ; Walsh et al, 2014 ). Taken together, these results suggest (1) that typical aging is associated with slower route learning, (2) that early atypical aging does not affect route learning, and (3) that aging as well as early atypical aging are associated with faster forgetting of route knowledge.…”