Protective effects of physical activity on episodic memory during aging are explained by executive functioning

Aging is marked by a memory decline related to an executive function decline. Physical activity (PA) has beneficial effects on both executive functions and memory, especially in aging. The protective effects of PA on these two cognitive abilities have always been studied separately, despite the well-established relationship between memory and executive functions. Our objective was to explore whether the benefits of PA on memory could be explained by reduced age-related changes in executive functions.Nineteen young adults (27.16 years old) and 25 older adults (69.64 years old) performed a resource-dependent memory task, three executive tasks and completed a PA questionnaire (measuring sports and leisure PA). Age group and PA effects on memory and executive performance were analyzed with generalized linear models. Mediation analyses were calculated using method of causal steps approach with a non-parametric bootstrapping procedure.The results confirmed the effects of age and PA on memory and executive performance. A significant interaction confirmed the protective effect of PA on age-related cognitive performance. PA was positively correlated with performance in both memory and executive tasks, but only in the older adults. Although each predictor alone (age, executive functions and PA) significantly explained memory performance in older adults, only the effect of PA on memory performance remained significant when all the predictors were introduced in the analyses.PA mediates the effects of age and executive functions on memory performance. This suggests that PA protects older adults against memory decline by reducing the decline in executive functioning.

Kinematic observation reduces effect of aging on episodic memory performance

This study investigated the influence of kinematics observation (i.e., observing action from only the motion of the main joints of an actor) on episodic memory performance differences between young and older adults. To this end, 42 young (20-35 years) and 45 older (60-75 years) participants performed a free recall task in two different conditions: either after an encoding phase consisting of the visual presentation and reading of action verbs or after an encoding phase consisting of the visual presentation and naming of point-light displays of humans performing the same actions. Results showed a beneficial effect of point-light display encoding for both young and older participants but with a more pronounced benefit for the older participants compared to young adults. These findings are discussed in relation to the embodied view of memory which considers that memory is directly linked to the sensorimotor experiences and the environmental support hypothesis which postulates that elaborate processing can improve memory performance. In conclusion, kinematic observation could constitute an interesting potential intervention for supporting memory in older adults.

The PAPA Questionnaire: Assessment of Long-Term Engagement in Activities, with Separate Quantification of Their Physical, Cognitive, and Social Components

Purpose

Engagement in activities promotes healthy living. Evaluating it is a challenging issue. Assessing engagement in activities while differentiating the physical, cognitive, and social component of each activity and taking into account the intensity level involved in each of the three components would be very relevant. Since none of the currently available cognitive reserve and questionnaires on the activities practiced takes into consideration both points, the purpose of this new questionnaire, called Pertinent Activities Practice in Adults (PAPA) questionnaire, is to fill these gaps.

Patients and Methods

The questionnaire was developed through a literature review and interviews with older adults (n=177 ≥55 years). The intensity level of each item (none, light, moderate, or high) was determined by the compendium of physical activities for the physical component and consensus for the cognitive and social components, then validated by 56 professional experts (6 groups: physiotherapists, neuropsychologists, occupational therapists, geriatricians, etc.).

Results

The PAPA questionnaire includes 75 items that give rise to 4 scores (sedentary lifestyle and physical, cognitive, and social activity scores) weighted by the frequency, duration, and intensity level for each component. The weighted percentage of agreement of the expert groups for the intensity levels was never significantly lower than the minimum target threshold (80% of the hypothetical median) except in a single domain (cognitive) for an expert group non-specialized in cognition. Cronbach's alpha was ≥0.85.

Conclusion

This questionnaire, which assesses long-term engagement in activities, with separate quantification of the physical, cognitive, and social components of a wide range of activities, should help guide actions to promote healthy aging and reduce dementia risk.

Episodic memory and aging: Benefits of physical activity depend on the executive resources required for the task

Physical activity has beneficial effects on executive functions and episodic memory, two processes affected by aging. These benefits seem to depend on the type of memory task, but only a few studies have evaluated them despite their importance in understanding aging. This study aimed to confirm that the benefits of physical activity on episodic memory in older adults vary according to the executive resources required by the memory task, comparing free recall and cued recall. Thirty-seven young adults and 37 older adults performed two memory tasks and an updating task. The two groups had a similar level of physical activity over the preceding 12 months, assessed by a questionnaire. Both the memory and the updating tasks were performed better by the younger than the older adults. A similar cueing effect was observed in the two groups. Physical activity was positively correlated with updating and free recall, but not with cued-recall, and only in older adults. Regression analyses indicated that physical activity accounted for 24% of the variance in free recall in older adults. Updating did not predict free recall (ns) when physical activity was entered in the analysis. The present results show that the benefits of physical activity vary with age and episodic memory task. Only free-recall performance, which relies on updating, seems to depend on physical activity, suggesting that the executive resources required for the task play an important role in the effect of physical activity on memory performance. This should be investigated in greater depth in subsequent studies.