The association of physical activity to neural adaptability during visuo-spatial processing in healthy elderly adults: A multiscale entropy analysis

Physical activity has been shown to benefit brain and cognition in late adulthood. However, this effect is still unexplored in terms of brain signal complexity, which reflects the level of neural adaptability and efficiency during cognitive processing that cannot be acquired via averaged neuroelectric signals. Here we employed multiscale entropy analysis (MSE) of electroencephalography (EEG), a new approach that conveys important information related to the temporal dynamics of brain signal complexity across multiple time scales, to reveal the association of physical activity with neural adaptability and efficiency in elderly adults. A between-subjects design that included 24 participants (aged 66.63±1.31years; female=12) with high physical activity and 24 age- and gender-matched low physical activity participants (aged 67.29±1.20years) was conducted to examine differences related to physical activity in performance and MSE of EEG signals during a visuo-spatial cognition task. We observed that physically active elderly adults had better accuracy on both visuo-spatial attention and working memory conditions relative to their sedentary counterparts. Additionally, these physically active elderly adults displayed greater MSE values at larger time scales at the Fz electrode in both attention and memory conditions. The results suggest that physical activity may be beneficial for adaptability of brain systems in tasks involving visuo-spatial information. MSE thus might be a promising approach to test the effects of the benefits of exercise on cognition.

The Unique Relation of Physical Activity to Executive Function in Older Men and Women

PURPOSE

To determine whether physical activity participation was specifically and positively associated with executive function in older individuals after accounting for age, education, and IQ.

METHODS

Participants were 120 healthy men (N = 38) and women (N = 82) aged 65-92 yr (mean = 78.9, SD = 5.8), who were free of depression and dementia (Beck Depression Inventory and Mini-Mental Status Exam, respectively), had above-average intelligence (mean = 118.1, SD = 9.4) as indexed by the Kaufman Brief Intelligence Test (K-BIT), and stable patterns of physical activity during a 3- to 5-yr period before the study. Participants completed the Yale Physical Activity Survey (YPAS) for older adults and the Stroop Color and Word Test to assess inhibitory executive function.

RESULTS

Hierarchical regression analyses revealed that YPAS summary index scores explained a small, but significant amount of variance in Stroop color-word and interference scores (DeltaR2 = 2 and 4%, respectively) after accounting for intelligence and age. The YPAS index was unrelated to nonexecutive performance.

CONCLUSIONS

The results support specificity of the physical activity/cognition relationship in older individuals. The results may be explained by additive benefit from participation in physical activity to the frontal lobe (i.e., beyond any benefits from cognitive stimulation), a region that mediates executive function and experiences accelerated age-related decline. In summary, habitual physical activity is positively related to executive performance in older men and women into the 10th decade.