Treadmill or Overground? Cognitive-Motor Interference Effects in Healthy Older Individuals

Walking is increasingly understood as a cognitively demanding activity requiring the integration of sensory processing, motor control and executive functions. When combined with a concurrent cognitive task (dual-tasking), cognitive-motor interactions may lead to changes in gait, behaviour and neurophysiology. In healthy aging, reduced motor automaticity may result in greater involvement of top-down control, increasing susceptibility to cognitive-motor interference and fall risk, even in the absence of clinical impairment. To explore real-world demands, we compared dual-tasking during outdoor overground walking and during indoor treadmill walking, using behavioural assessment of cognitive task performance, mobile electroencephalography and motion tracking with wearable sensors. Thirty-six older adults performed an auditory Go/No-Go task during both walking conditions and in a seated control condition. Compared to a stationary control condition, results confirmed significant dual-task interference effects during both walking conditions, and this effect was more pronounced during overground walking. The results suggest that overground walking imposes greater demands, leading to increased competition between cognitive and motor processes for shared cognitive resources. The consideration of natural conditions helps to identify the cognitive demands of locomotion.