Literacy Level and Executive Control in Healthy Older Peruvian Adults

Moderating effects of cognitive reserve on the relationship between brain structure and cognitive abilities in middle-aged and older adults

The cognitive reserve (CR) hypothesis is reinforced by negative moderating effects, suggesting that those with higher CR are less reliant on brain structure for cognitive function. Previous research on CR's moderating effects yielded inconsistent results, motivating our 3 studies using UK Biobank data. Study I examined five CR proxies' moderating effects on global, lobar, and regional brain-cognition models; study II extended study I by using a larger sample size; and study III investigated age-related moderating effects on the hippocampal regions. In study I, most moderating effects were negative and none survived the multiple comparison correction, but study II identified 13 global-level models with significant negative moderating effects that survived correction. Study III showed age influenced CR proxies' moderating effects in hippocampal regions. Our findings suggest that the effects of CR proxies on brain integrity and cognition varied depending on the proxy used, brain integrity indicators, cognitive domain, and age group. This study offers significant insights regarding the importance of CR for brain integrity and cognitive outcomes.

Cognitive reserve, cognition, and real-world functioning in MCI: A systematic review and meta-analysis

OBJECTIVE

To synthesize quantitatively the mild cognitive impairment (MCI) literature with respect to the relationship between cognitive reserve and neuropsychological and functional outcomes.

METHOD

Participants with a diagnosis of MCI (total n = 7,871; 53% female) were included in this random-effects meta-analysis. Neuropsychological measures were combined into composite scores (e.g., overall cognitive functioning, screening measures, memory, language, visuospatial, attention/processing speed/working memory, executive functioning, and motor functioning). Measures assessing real-world abilities were combined into an activities of daily living (ADL) composite.

RESULTS

Nearly all neuropsychological composite values were significantly correlated with education, with effect sizes ranging from small to moderate. The effect between overall neuropsychological functioning and occupation was weak and varied by cognitive domain. For cognitively stimulating leisure activity, only overall neuropsychological functioning demonstrated a significant relationship, with a weak effect size (r = .16). In contrast, ADLs were most strongly associated with leisure experience (r = .27), with a negligible relationship with education (r = 0.08) and occupation (r = 0.09).

CONCLUSIONS

Of the cognitive reserve proxies examined in this study, participation in leisure activity had the largest magnitude of effect size with ADL functioning. This was in stark contrast to the negligible relationship found for education and occupation. Although education has been widely considered the most important cognitive reserve proxy with respect to cognition, this work questions whether other lifestyle factors may play a more important role in preserving real world functioning.