Frequent cognitive activity compensates for education differences in episodic memory.

OBJECTIVES To test the hypothesis that frequent participation in cognitive activities can moderate the effects of limited education on cognitive functioning. DESIGN A national study of adult development and aging, Midlife in the United States, with assessments conducted at the second wave of measurement in 2004-2006. SETTING Assessments were made over the telephone (cognitive measures) and in a mail questionnaire (demographic variables, measures of cognitive and physical activity, and self-rated health). PARTICIPANTS A total of 3,343 men and women between the ages of 32 and 84 with a mean age of 55.99 years. MEASUREMENTS The dependent variables were Episodic Memory (Immediate and Delayed Word List Recall) and Executive Functioning (Category Fluency, Backward Digit Span, Backward Counting Speed, Reasoning, and Attention Switching Speed). The independent variables were years of education and frequency of cognitive activity (reading, writing, doing word games or puzzles, and attending lectures). The covariates were age, sex, self-rated health, income, and frequency of physical activity. RESULTS The two cognitive measures were regressed on education, cognitive activity frequency, and their interaction, while controlling for the covariates. Education and cognitive activity were significantly correlated with both cognitive abilities. The interaction of education and cognitive activity was significant for episodic memory but not for executive functioning. CONCLUSION Those with lower education had lower cognitive functioning, but this was qualified by level of cognitive activity. For those with lower education, engaging frequently in cognitive activities showed significant compensatory benefits for episodic memory, which has promise for reducing social disparities in cognitive aging.