Thirty-one young (mean age = 20.8 years) and 30 older (mean age = 71.5 years) men and women categorized as physically active (n = 30) or inactive (n = 31) performed an executive processing task while standing, treadmill walking at a preferred pace, and treadmill walking at a faster pace. Dual-task interference was predicted to negatively impact older adults’ cognitive flexibility as measured by an auditory switch task more than younger adults; further, participants’ level of physical activity was predicted to mitigate the relation. For older adults, treadmill walking was accompanied by significantly more rapid response times and reductions in local- and mixed-switch costs. A speed-accuracy tradeoff was observed in which response errors increased linearly as walking speed increased, suggesting that locomotion under dual-task conditions degrades the quality of older adults’ cognitive flexibility. Participants’ level of physical activity did not influence cognitive test performance.
Tomporowski is in the Department of Kinesiology at the University of Georgia, Athens, GA. Audiffren is in the Research Institute on Cognition and Learning, UMR CNRS 7295, Sport Sciences Faculty at the University of Poitiers, Poitiers, France.