Mobile Brain/Body Imaging in Younger and Older Adults during Dual-Task Walking

COEX 

Walking can be an essential motor skill for independent living. However, even daily walking may compete with other concurrent activities, such as navigating routes, for limited shared resources. Age-related changes in cognitive or motor skills, as well as potential dependencies between tasks, can lead to performance declines in one or both tasks (e.g. Fraser & Bherer, 2013).

Despite the application of various behavioral, kinematic, and neurophysiological measures, a comprehensive understanding of cognitive motor interference in dual-task walking has not yet been achieved. Behavioral studies in realistic movement conditions lack sufficient information about the sources and timing of sub-processes that drive observable behavior. Neuroimaging studies, on the other hand, are often conducted in restricted and artificially induced movement scenarios due to the technical constraints of several imaging modalities. For a deeper understanding of performance in dual-task scenarios, it is essential to combine different types of data recorded in scenarios that allow for natural behavior.

In this presentation, I will outline our recent Mobile Brain/Body Imaging (MoBI, Makeig et al., 2009; Gramann et al., 2011; 2014) research on age-related performance changes during dual-task walking. We conducted two studies to examine the behavioral and EEG data from younger (< 35 years) and older participants (>65 years) as they completed simple visual tasks while sitting, standing, and walking on level ground. We observed that dual-task walking had a greater impact on older participants as compared to younger participants. This was characterized by a decrease in walking speed, diminished visual task accuracy and reduced amplitudes and prolonged latencies of the event-related potential P1. While walking, delayed responses in the visual task were linked to prolonged P1 latencies, and reduced P1 amplitudes were associated with an increased number of missed visual targets in both groups (Protzak, Wiczorek & Gramann, 2021). Time-frequency data analysis revealed that power modulations within motor cortex areas between button presses performed while sitting and walking were reduced in older participants, and less pronounced changes in the beta and alpha band were associated with a greater reduction in walking speed in both groups (Protzak, Wiczorek & Gramann, 2021). Our current analysis indicates that modulations in the periodic component of the power spectrum of motor cortex areas are linked to changes in walking speed when shifting from single-task to dual-task walking.

Our results contribute to the understanding of cognitive-motor interference during dual-task walking in younger and older adults. We observed changes in early attentional-perceptual processing and motor resource allocation that were related to the task and the age group, even in simple dual-task paradigms.