Imagine you’re practicing a dance routine. The more you practice, the better you get, right? Well, the same goes for our memory! In a longitudinal study of normally-aging older adults, researchers investigated the effects of aging and repeated testing on episodic memory and executive function. They found that memory performance actually improved with each testing session, thanks to the power of practice! However, once they removed the practice effects, they discovered that both memory and executive function declined over time due to aging. They also found that individuals with higher IQs experienced slower age-related declines in memory. Interestingly, sex and IQ affected performance initially, but had no impact on practice effects. Young-older adults seemed to benefit more from practice compared to old-older adults. These findings highlight the importance of considering practice effects when studying cognitive changes in older adults. So, next time you want to improve your memory, don’t forget to give it some good ol’ practice time! If you’re curious to learn more about this fascinating study, check out the full article.

Episodic memory and executive function are two cognitive domains that have been studied extensively in older adults and have been shown to decline in normally-aging older individuals. However, one of the problems with characterizing cognitive changes in longitudinal studies has been separating effects attributable to normal aging from effects created by repeated testing or practice. In the present study, 166 people aged 65 and older were enrolled over several years and tested at least 3 times at variable intervals (M = 3.2 yrs). The cognitive measures were composite scores. Each composite was made up of five neuropsychological tests, previously identified through factor analysis. For one pair of composite scores, variance attributable to age was removed from each subtest through regression analyses before z-scores were computed, creating two age-corrected composites. A second pair of composites were not age-corrected. Using linear mixed-effects models, we first explored retest effects for each cognitive domain, independent of age, using the age-corrected composites. We then modeled aging effects using the age-uncorrected composites after subtracting out retest effects. Results indicated significant retest effects for memory but not for executive function, such that memory performance improved across the three testing sessions. When these practice effects were removed from the age-uncorrected data, effects of aging were evident for both executive and memory function with significant declines over time. We also explored several individual difference variables including sex, IQ, and age at the initial testing session and across time. Although sex and IQ affected performance on both cognitive factors at the initial test, neither was related to practice effects, although young-older adults tended to benefit from practice to a greater extent than old-older adults. In addition, people with higher IQs showed slower age-related declines in memory, but no advantages in executive function. These findings suggest that (a) aging affects both memory and executive function similarly, (b) higher IQ, possibly reflecting cognitive reserve, may slow age-related declines in memory, and (c) practice through repeated testing enhances performance in memory particularly in younger-older adults, and may therefore mask aging effects if not taken into account.

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