title: The neural control of bimanual movements in the elderly: Brain regions exhibiting age-related increases in activity, frequency-induced neural modulation, and task-specific compensatory recruitment.
abstract: Coordinated hand use is an essential component of many activities of daily living. Although previous studies have demonstrated age-related behavioral deficits in bimanual tasks, studies that assessed the neural basis underlying such declines in function do not exist. In this fMRI study, 16 old and 16 young healthy adults performed bimanual movements varying in coordination complexity (i.e., in-phase, antiphase) and movement frequency (i.e., 45, 60, 75, 90% of critical antiphase speed) demands. Difficulty was normalized on an individual subject basis leading to group performances (measured by phase accuracy/stability) that were matched for young and old subjects. Despite lower overall movement frequency, the old group "overactivated" brain areas compared with the young adults. These regions included the supplementary motor area, higher order feedback processing areas, and regions typically ascribed to cognitive functions (e.g., inferior parietal cortex/dorsolateral prefrontal cortex). Further, age-related increases in activity in the supplementary motor area and left secondary somatosensory cortex showed positive correlations with coordinative ability in the more complex antiphase task, suggesting a compensation mechanism. Lastly, for both old and young subjects, similar modulation of neural activity was seen with increased movement frequency. Overall, these findings demonstrate for the first time that bimanual movements require greater neural resources for old adults in order to match the level of performance seen in younger subjects. Nevertheless, this increase in neural activity does not preclude frequency-induced neural modulations as a function of increased task demand in the elderly.
authors.affiliation: Research Center for Movement Control and Neuroplasticity, Department for Biomedical Kinesiology, Katholieke Universiteit Leuven, Heverlee, Belgium. daniel.goble@faber.kuleuven.be
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Goble
authors.forename: James P
authors.initials: JP
authors.lastname: Coxon
authors.forename: Annouchka
authors.initials: A
authors.lastname: Van Impe
authors.forename: Jeroen
authors.initials: J
authors.lastname: De Vos
authors.forename: Nicole
authors.initials: N
authors.lastname: Wenderoth
authors.forename: Stephan P
authors.initials: SP
authors.lastname: Swinnen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D001696:Biomechanical Phenomena; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000294:innervation*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D011597:Psychomotor Performance / Q000502:physiology*; D013223:Statistics as Topic; D014953:Wrist / Q000294:innervation; D055815:Young Adult
chemical_list: D010100:Oxygen