title: Movement-related phase locking in the delta-theta frequency band.
abstract: Movements result from a complex interplay of multiple brain regions. These regions are assembled into distinct functional networks depending on the specific properties of the action. However, the nature and details of the dynamics of this complex assembly process are unknown. In this study, we sought to identify key markers of the neural processes underlying the preparation and execution of motor actions that always occur irrespective of differences in movement initiation, hence the specific neural processes and functional networks involved. To this end, EEG activity was continuously recorded from 18 right-handed healthy participants while they performed a simple motor task consisting of button presses with the left or right index finger. The movement was performed either in response to a visual cue or at a self-chosen, i.e., non-cued point in time. Despite these substantial differences in movement initiation, dynamic properties of the EEG signals common to both conditions could be identified using time-frequency and phase locking analysis of the EEG data. In both conditions, a significant phase locking effect was observed that started prior to the movement onset in the δ-θ frequency band (2-7Hz), and that was strongest at the electrodes nearest to the contralateral motor region (M1). This phase locking effect did not have a counterpart in the corresponding power spectra (i.e., amplitudes), or in the event-related potentials. Our finding suggests that phase locking in the δ-θ frequency band is a ubiquitous movement-related signal independent of how the actual movement has been initiated. We therefore suggest that phase-locked neural oscillations in the motor cortex are a prerequisite for the preparation and execution of motor actions.
authors.affiliation: Heisenberg Research Group of Computational Biology, Department of Animal Physiology, Institute of Zoology, University of Cologne, Köln, Germany; Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Popovych
authors.affiliation: Heisenberg Research Group of Computational Biology, Department of Animal Physiology, Institute of Zoology, University of Cologne, Köln, Germany; Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Rosjat
authors.affiliation: Heisenberg Research Group of Computational Biology, Department of Animal Physiology, Institute of Zoology, University of Cologne, Köln, Germany.
authors.forename: T I
authors.initials: TI
authors.lastname: Toth
authors.affiliation: Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany.
authors.forename: B A
authors.initials: BA
authors.lastname: Wang
authors.affiliation: Heisenberg Research Group of Computational Biology, Department of Animal Physiology, Institute of Zoology, University of Cologne, Köln, Germany; Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Liu
authors.affiliation: Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany.
authors.forename: R O
authors.initials: RO
authors.lastname: Abdollahi
authors.affiliation: Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany; Department of Neurology, University Hospital Cologne, Köln, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Viswanathan
authors.affiliation: Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany; Department of Neurology, University Hospital Cologne, Köln, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Grefkes
authors.affiliation: Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany; Department of Neurology, University Hospital Cologne, Köln, Germany.
authors.forename: G R
authors.initials: GR
authors.lastname: Fink
authors.affiliation: Heisenberg Research Group of Computational Biology, Department of Animal Physiology, Institute of Zoology, University of Cologne, Köln, Germany; Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Centre Jülich, Jülich, Germany. Electronic address: s.gruhn@fz-juelich.de.
authors.forename: S
authors.initials: S
authors.lastname: Daun
mesh_terms: D000328:Adult; D003344:Cortical Synchronization; D003700:Delta Rhythm; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D005385:Fingers; D006801:Humans; D008297:Male; D009043:Motor Activity; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement; D011597:Psychomotor Performance; D013826:Theta Rhythm; D055815:Young Adult
keywords: Externally triggered motor action; Finger tapping; Movement initiation; Voluntary motor action