We found that those with lower education had poorer cognitive performance for executive functioning and episodic memory, and engaged in cognitive activities less frequently, consistent with previous research.(18
) In addition, greater engagement in cognitive activities was associated with better memory and executive functioning.(18
) Moreover, we found new evidence that the association between lower education and poorer memory can be moderated by engaging in frequent cognitive activities. These findings are promising for reducing the social disparities in cognitive aging, associated with educational attainment, using modifiable behavioral factors.(1
There are some notable strengths of this study. It is based on a large national data set that includes a more diverse sample than many previous studies with regard to age and education levels. The study also includes a broad test battery that covers key aspects of cognition that are associated with cognitive aging and are sensitive to changes across the adult lifespan.(34
) Notably, we found effects for cognitive activities after controlling for the effects of physical activity, whereas the unique variance of both types of activity has rarely been examined in other studies.
The finding that a modifiable behavior, cognitive activity, makes an even greater difference for the memory functioning of those with lower education levels than for those with higher education is an important contribution. This gives evidence of the possibility for some degree of personal control over cognitive functioning in adulthood by adopting a cognitively active lifestyle, even for those who are at an educational disadvantage, and who are at greatest risk for cognitive declines and dementia.(36
) The results indicate that among those with lower education levels (i.e., 1 SD
below the mean; those without a college education), engagement in more frequent cognitive activity, on the order of once a week or more (i.e., 1 SD
above the mean), is associated with more then a third (.36) of a standard deviation increase in mean level of episodic memory.
If participating in accessible cognitive activities can compensate for a significant portion of the cognitive disadvantage of lower education in adulthood and old age, this can provide a useful prescription for improved functioning. It is impressive that those with lower education who engaged in frequent cognitive activities had memory performance more comparable to those with higher educational attainment (college degree or higher). The effects for episodic memory remained even when controlling for age, sex, income, and self-rated health, suggesting that the results hold across the adult age range of men and women, and are not due to income or self-rated health differences. Moreover, the effects for cognitive activity were found over and above the effects of physical activity.(29
) In contrast, for executive functioning, although cognitive activity was positively related, the effects did not vary by educational level.
The cognitive activities we examined may be a more robust compensatory factor for memory because they involve memory-related processes. Similar cognitive activities have been shown to alter responsiveness of the brain's neural circuits in middle-aged and older adults, with advantages for neuroplasticity in hippocampal functioning (37
), a region important for memory and learning.(39
The study results are promising and suggest that the risks of lower education for poor cognitive performance, especially memory, may be attenuated with engagement in common cognitive activities such as writing, reading, attending lectures, or playing word games, at least once a week or more. The compensatory effects of cognitive activity for memory were most pronounced for those who have less education. For those with less education, these activities may afford enriched opportunities for using, rehearsing, and practicing memory-related skills required for reading, writing, processing verbal information, and playing games.
The study also has some limitations. As is typically found, the participants who completed all measures were positively selected compared to those not included in analyses due to incomplete data [i.e., included participants had higher education (14.28 vs. 13.88 years) and better self-rated health (3.57 vs. 3.45)]. Also, the data are cross-sectional and cannot provide conclusive evidence about directionality. It is possible that those with lower education who have better cognitive performance are more likely to engage in cognitive activities. Moreover, we used a brief self-report measure of cognitive activity, and we do not know if participants were accurate in their ratings. Thus, more research is needed to gain further insight into the processes whereby education, cognitive activity, and cognition are related in adulthood and old age. Additional work is also need to determine whether engaging in frequent cognitive activities has a protective effect for dementia among those with lower education as well as for better-educated individuals.(22
) Nevertheless, these findings hold promise for modifying risks of cognitive decline in less-advantaged populations, by encouraging frequent engagement in relatively accessible activities.