Can Walking Improve Cognitive Functioning for Older Adults? A Randomized Intervention

Abstract

Healthy older adults, even those who do not display signs of dementia, show gradual declines in cognitive functioning as they age that are correlated with neural atrophy, the weakening of synapses, and decreases in cortical vasodilatation. FMRI analysis further shows that high performing older adults show functional shifts from posterior activation to more frontal activation, which may be representative of compensatory neural plasticity. Physical fitness is highly correlated with reduced risk of dementia, and aerobic exercise has been shown to have many beneficial and protective influences on brain functioning. This senior thesis summarizes findings from a randomized experiment I conducted that implemented a month-long exercise intervention with a group of 39 adults who were age 55 and older. During the study period, the randomly selected treatment group was provided with handheld pedometers and encouraged to walk two or more miles a day. Using working memory tasks to measure changes in cognitive performance, I found a statistically significant treatment effect on performance gains on the backward digit span, and on a composite test score when age, gender, and education were controlled. There was no significant treatment effect for the forward digit span test and matrix span, a spatial working memory task. In view of the encouraging findings in this study, it would be desirable for future research to recruit a larger sample and measure the effects of the pedometer intervention on improvements on a wider variety of cognitive assessments.