Positive impact of cognitive reserve on the dynamics of selected cognitive functions in a 3-month follow-up of adult Poles

Abstract

https://orcid.org/0000-0003-3383-0353 Introduction: David Snowden’s 25-year longitudinal Nun Study has contributed to the ongoing interest in the relationship between cognitive reserve and cognitive performance in adults. The term “cognitive reserve” refers to the capital of knowledge and skills. Greater cognitive reserve accounts for good baseline cognitive status of adults and may translate into successful aging. Therefore, research was undertaken to assess the role of cognitive reserve and age in shaping the results of tests assessing cognitive functions and self-report methods. Methods: The study was conducted among adult Poles (N = 80) and involved two measurements (at baseline and after 3 months). The cognitive reserve index included self-report data on past and present involvement in various areas of life, years of occupational activity, level of formal education and occupational status. Each of these categories was scored. Cognitive functions were assessed twice using verbal fluency tests, the Wechsler Adult Intelligence Scale – Revised (WAIS-R) subtests, the Zoo Map subtest, the Trail Making Test (TMT), self-report tools such as the Dysexecutive Questionnaire – Self (DEX-S) and the Prospective and Retrospective Memory Questionnaire (PRMQ), as well as the Beck Depression Inventory (BDI-II). Results: Age was negatively correlated with test results, while greater cognitive reserve contributed to better outcomes, which was observed both at baseline and follow-up. The same assessments performed separately for the group of younger (≤55 years of age) and older (≥56 years) adults revealed the negative effect of age in the older group, with less pronounced positive effect of cognitive reserve. Discussion: The results correspond to previous findings. Attention, cognitive flexibility, working memory and planning abilities deteriorate with age. High levels of cognitive reserve account for improvement of these functions both at baseline and at 3 months. However, age, the negative role of which is particularly evident in individuals aged ≥56 years, is the strongest determinant of task performance. Conclusions: The relationship between deteriorated cognitive functions and the protective role of cognitive reserve may vary at different stages of adulthood. Adverse effects of age on cognitive abilities are more pronounced, while the protective effects of cognitive reserve cease in individuals aged ≥56 years. This may indicate that in the presence of other unfavourable factors, such as multimorbidity, cognitive reserve has no significant impact on the ageing trajectory.