Distinct roles of brain network flexibility in motor learning across age

Motor learning is a lifelong process, from infancy through old age. Acquiring new motor skills through repetitive practice requires adjusting motor output in response to sensory input and integrating them to facilitate learning. For this to occur, the central nervous system must flexibly predict and adapt to the dynamic interplay between sensory inputs and motor outputs. Although overall brain function changes with age, it remains unclear how neural flexibility evolves and influences motor learning ability with aging. To address this, we designed a motor learning paradigm involving both younger and older adults and quantitatively assessed neural flexibility from the perspective of functional brain networks, leveraging multichannel electroencephalography (EEG) in humans. Here we found age-related differences in motor learning properties, brain network flexibility, and their neural relationships. In younger adults, motor learning retention was associated with brain network flexibility during the preparatory period of the task. However, this association was not observed in older adults. Together, our findings establish that brain network flexibility plays a crucial role in acquiring and maintaining new motor skills in younger adults, but this relationship becomes less effective with age.