title: Using motor imagery to study the neural substrates of dynamic balance.
abstract: This study examines the cerebral structures involved in dynamic balance using a motor imagery (MI) protocol. We recorded cerebral activity with functional magnetic resonance imaging while subjects imagined swaying on a balance board along the sagittal plane to point a laser at target pairs of different sizes (small, large). We used a matched visual imagery (VI) control task and recorded imagery durations during scanning. MI and VI durations were differentially influenced by the sway accuracy requirement, indicating that MI of balance is sensitive to the increased motor control necessary to point at a smaller target. Compared to VI, MI of dynamic balance recruited additional cortical and subcortical portions of the motor system, including frontal cortex, basal ganglia, cerebellum and mesencephalic locomotor region, the latter showing increased effective connectivity with the supplementary motor area. The regions involved in MI of dynamic balance were spatially distinct but contiguous to those involved in MI of gait (Bakker et al., 2008; Snijders et al., 2011; Crémers et al., 2012), in a pattern consistent with existing somatotopic maps of the trunk (for balance) and legs (for gait). These findings validate a novel, quantitative approach for studying the neural control of balance in humans. This approach extends previous reports on MI of static stance (Jahn et al., 2004, 2008), and opens the way for studying gait and balance impairments in patients with neurodegenerative disorders.
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, the Netherlands.
authors.forename: Murielle Ursulla
authors.initials: MU
authors.lastname: Ferraye
authors.affiliation: Grenoble Institut des Neurosciences, INSERM U838, Université de Grenoble, Grenoble, France.
authors.forename: Bettina
authors.initials: B
authors.lastname: Debû
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, the Netherlands.
authors.forename: Lieke
authors.initials: L
authors.lastname: Heil
authors.affiliation: School of Kinesiology, University of British Columbia, Vancouver, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Carpenter
authors.affiliation: Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands.
authors.forename: Bastiaan Roelof
authors.initials: BR
authors.lastname: Bloem
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, the Netherlands.
authors.forename: Ivan
authors.initials: I
authors.lastname: Toni
mesh_terms: D001519:Behavior / Q000502:physiology; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D005684:Gait / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D004856:Postural Balance / Q000502:physiology*; D055815:Young Adult