Modulating Brain Activity to Improve Goal-directed Physical Activity in Older Adults

Although the majority of older adults are aware of the compelling evidence that regular exercise is critical to the maintenance of health into old age, most do not meet recommendations for daily exercise. This lack of engagement in 'goal-directed' physical activity stems from numerous interrelated factors including lack of motivation, depressed mood, and cognitive "executive" impairments that diminish one's ability to regulate behavior over time. Intriguingly, each of these factors has been linked to the function of brain networks that include the left dorsolateral prefrontal cortex (dlPFC). Transcranial direct current stimulation (tDCS) is a noninvasive and safe means of modulating the excitability of specific brain regions and their connected neural networks. tDCS designed to facilitate the excitability of the left dlPFC has been shown to improve motivation, mood, and multiple aspects of executive function in healthy adults. The investigators thus hypothesize that tDCS holds promise to increase goal-directed physical activity in older adults. This project aims to conduct a pilot randomized controlled trial on the feasibility and effects of a 2-week, 10-session tDCS intervention targeting the left dlPFC, combined with behavioral intervention aimed at increases daily physical activity, on physical activity over a two-month follow-up period, in relatively sedentary older adults without overt illness or disease.