title: Distinct roles for alpha- and beta-band oscillations during mental simulation of goal-directed actions.
abstract: Rhythmic neural activity within the alpha (8-12 Hz) and beta (15-25 Hz) frequency bands is modulated during actual and imagined movements. Changes in these rhythms provide a mechanism to select relevant neuronal populations, although the relative contributions of these rhythms remain unclear. Here we use MEG to investigate changes in oscillatory power while healthy human participants imagined grasping a cylinder oriented at different angles. This paradigm allowed us to study the neural signals involved in the simulation of a movement in the absence of signals related to motor execution and sensory reafference. Movement selection demands were manipulated by exploiting the fact that some object orientations evoke consistent grasping movements, whereas others are compatible with both overhand and underhand grasping. By modulating task demands, we show a functional dissociation of the alpha- and beta-band rhythms. As movement selection demands increased, alpha-band oscillatory power increased in the sensorimotor cortex ipsilateral to the arm used for imagery, whereas beta-band power concurrently decreased in the contralateral sensorimotor cortex. The same pattern emerged when motor imagery trials were compared with a control condition, providing converging evidence for the functional dissociation of the two rhythms. These observations call for a re-evaluation of the role of sensorimotor rhythms. We propose that neural oscillations in the alpha-band mediate the allocation of computational resources by disengaging task-irrelevant cortical regions. In contrast, the reduction of neural oscillations in the beta-band is directly related to the disinhibition of neuronal populations involved in the computations of movement parameters.
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, 6500 HB Nijmegen, The Netherlands and L.Brinkman@donders.ru.nl.
authors.forename: Loek
authors.initials: L
authors.lastname: Brinkman
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, 6500 HB Nijmegen, The Netherlands and.
authors.forename: Arjen
authors.initials: A
authors.lastname: Stolk
authors.affiliation: Utrecht University, Helmholz Institute, Experimental Psychology, 3584 CS Utrecht, The Netherlands.
authors.forename: H Chris
authors.initials: HC
authors.lastname: Dijkerman
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, 6500 HB Nijmegen, The Netherlands and.
authors.forename: Floris P
authors.identifier: http://orcid.org/0000-0002-6730-1452
authors.initials: FP
authors.lastname: de Lange
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, 6500 HB Nijmegen, The Netherlands and.
authors.forename: Ivan
authors.identifier: http://orcid.org/0000-0003-0936-3601
authors.initials: I
authors.lastname: Toni
mesh_terms: D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology*; D001611:Beta Rhythm / Q000502:physiology*; D005260:Female; D006040:Goals; D006801:Humans; D007092:Imagination / Q000502:physiology*; D015225:Magnetoencephalography; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: efference copy; magnetoencephalography; motor imagery; motor plan; movement preparation; sensorimotor cortex