Education and Cognition in Middle Age and Later Life: The Mediating Role of Physical and Cognitive Activity

Abstract

Objectives: Although educational attainment is related to cognitive function in later life, little is known about the mechanisms involved. This study assessed the independent mediating effects of two behavioral variables, physical and cognitive activity, on the association between educational attainment and cognitive function and change.

Methods: Data were derived from the three waves of the Midlife in the United States (MIDUS) study. Predictors (educational attainment) were from the 1995 baseline, mediators (physical and cognitive activities) were from the 2004 wave, and outcomes (cognitive function) were from the 2004 and 2013 waves. Conditional process modeling was applied using PROCESS in SPSS.

Results: There were both direct and indirect effects of educational attainment on level and change of executive function (EF) and episodic memory (EM). Physical activity and cognitive activity were both significant mediators for cognitive level. For mediators of change, however, cognitive activity was significant for EF and physical activity was significant for EM.

Discussion: Physical and cognitive activity are discussed as possible factors for protecting against cognitive decline in later life. The findings have implications for advancing supportive policies and practices related to maximizing the benefits of education and physical and cognitive activities for cognition in middle age and later life.

Keywords: Cognition; Education; Health; Mediation analysis.

© The Author(s) 2019. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Figures

Figure 1.

Mediation models for executive function (Model 1) and executive function change (Model 2). Model 1: the relationship of education and level of executive function, mediated by physical activity and cognitive activity. *p < .05. Model 2: the relationship of education and change in executive function, mediated by physical activity and cognitive activity. Model 2 parameters are presented in square brackets. *p < .05. Indirect effect of physical activity: 0.004, 95% CI: 0.002, 0.006, κ2 = 0.012 [0.001, 95% CI: −0.001, 0.002, κ2 = 0.001]; indirect effect of cognitive activity: 0.013, 95% CI: 0.009, 0.016, κ2 = 0.035 [0.001, 95% CI: 0.001, 0.002, κ2 = 0.006].

Figure 2.

Mediation models for episodic memory (Model 3) and episodic memory change (Model 4). Model 3: the relationship of education and level of episodic memory, mediated by physical activity and cognitive activity. *p < .05. Model 4: the relationship of education and change in episodic memory, mediated by physical activity and cognitive activity. Model 4 parameters are presented in square brackets. *p < .05. Indirect effect of physical activity: 0.003, 95% CI: 0.001, 0.005, κ2 = 0.008 [0.003, 95% CI: 0.001, 0.005, κ2 = 0.037]; indirect effect of cognitive activity: 0.007, 95% CI: 0.004, 0.009, κ2 = 0.033 [0.002, 95% CI: −0.001, 0.004, κ2 = 0.001].