Domain-Specific Functional Network Adaptations Supporting Dual-Task Performance in Older Adults

Aging is associated with declines in both motor and cognitive functions, which are well captured by dual task gait paradigms. However, the functional brain network mechanisms supporting motor and cognitive aspects of dual task performance in aging remain unclear. We examined 40 older adults (50 to 80 years) and 20 younger adults (20 to 40 years) who performed a motor single task (pedaling), a cognitive single-task (Go/NoGo), and a combined cognitive motor dual task during functional magnetic resonance Imaging (fMRI) using a custom-built MRI compatible pedaling device. Behaviorally, older adults showed significant dual task costs in motor performance, while cognitive performance was preserved. Neurally, older adults showed selective increases in connectivity within executive and motor-planning regions of cognitive networks, consistent with compensatory recruitment, whereas motor networks underwent broader reorganization, with strengthened frontoparietal control circuits but weakened cerebello-parietal and sensorimotor pathways. Multivariate analyses further revealed age related differences in latent connectivity behavior relationships: motor network patterns in older adults were more dispersed, reflecting heterogeneous reorganization, whereas cognitive-network patterns were more overlapping across groups, suggesting relative preservation. These findings suggest that aging involves a domain specific balance of resilience and vulnerability across brain networks and highlight motor-network adaption as a promising target for understanding why some older adults maintain function while others decline.