Age-Related Differences in Bimanual Coordination Are Associated with Increased Cerebellar Activity and Reduced Frontal Recruitment

Bimanual coordination declines in late adulthood, but the neural mechanisms underlying these changes remain unclear. Age-related differences in brain activity have been interpreted either as compensatory recruitment of frontal cognitive control regions or as a shift toward feedback-based control, supported by sensory and cerebellar processing systems. To investigate these hypotheses, we examined brain activity, using fMRI in twenty-three younger and twenty-three older adults performing a bimanual visuomotor pinch-force task with different task complexities. Behaviourally, older adults showed lower accuracy than younger adults, particularly when task demands increased. Neuroimaging results revealed general age-dependent increases in activity within posterior cerebellar lobules VI-VII, regions overlapping with the classical oculomotor vermis and implicated in visuomotor adaptation, movement calibration, and error-based motor learning. In addition, during the more demanding task condition, older adults showed a greater increase in activation of anterior cerebellar lobules IV-V and a decrease in activation of the medial frontal pole (BA10). No consistent age-related increases or decreases in task related activation was observed in parieto-frontal regions. Moreover, better task performance across age groups was associated with lower activation in frontal cognitive control regions, including the superior medial frontal gyrus and right inferior frontal gyrus. Together, these results suggest increased feedback- and error-related sensorimotor processing in older adults involving the cerebellum and frontal cortex.