Higher Level of Cognitive Reserve Reduces the Risk of Cognitive Difficulties in Healthy Adults

Abstract

The study was designed to investigate whether a level of cognitive reserve (CR) is associated with a level of cognitive competences in adults. Evidence from numerous earlier studies suggests that high CR, defined as previously acquired knowledge and experience, plays a protective role with respect to cognitive capacities in adults and senior citizens. Hence, it was hypothesised that a lower CR would predict lower cognitive capacities. The study involved 120 Polish healthy adults (75 women and 45 men) ranging in age from 40 to 85 years (M = 57.42; SD = 10.48). The applied CR index took into account formal education level, involvement in social, occupational and physical activity, and level of social support. The recorded data also included depression level (Beck Depression Inventory, BDI II) and cardiovascular status (hypertension: yes / no). The subjects’ current cognitive competences were assessed using Montreal Cognitive Assessment test (MoCA), Wechsler Adult Intelligence Scale (WAIS) subtests, verbal fluency tests and Dysexecutive Questionnaire, self-report version (DEX-S). Based on the subjects’ scores in cognitive tests, a cluster analysis was performed, and the participants were divided into two groups presenting lower cognitive level (LCL) and higher cognitive level (HCL). The LCL subjects were older than HCL and they had higher level of depression and lower CR. In order to determine whether lower level of CR is related to lower level of cognitive abilities in the adults, logistic regression analysis was carried out, also taking into account age, cardiovascular status and depression level. It was shown that the higher level of CR reduced the risk of cognitive deficits. Older age corresponds to poorer cognitive function. The findings showed no interaction between CR and age. Depression and health status did not predict level of cognitive abilities. The current findings are consistent with results of earlier studies: higher level of CR may be associated with a lower risk of cognitive deficits and age is a CR–independent variable that affects cognitive performance: the risk of cognitive decline increases with age. These findings are discussed with reference to models and CR indices.