Beta rebound after different types of motor imagery in man.
We investigated the behavior of short-lasting beta bursts (beta rebound, beta ERS) induced after imagination of hand, foot or tongue movement. Nine able-bodied subjects were asked to imagine one type of movement following the presentation of a visual cue stimulus. EEG was recorded from 60 closely spaced electrodes placed over frontal, central and parietal areas. Spatiotemporal ERD/ERS patterns were evaluated in form of time-frequency maps. Seven out of nine subjects displayed a significant short-lasting beta power increase (beta rebound) after termination of imagery of movement of both feet in the frequency range of 23-29Hz with a clear maximum at the vertex. In contrast, only two subjects displayed a clear beta rebound at the vertex after imagery of one of the hands, although five exhibited a significant beta rebound at the contralateral side of the head. None showed a beta rebound after tongue motor imagery. The midcentrally located beta rebound is interpreted as an electrophysiological correlate of a simultaneous "resetting" of overlapping neural networks in the foot representation areas and the SMA.
Pfurtscheller
G
G
Institute for Human-Computer Interfaces, Graz University of Technology, Inffeldgasse 16a, 8010 Graz, Austria. pfurtscheller@tugraz.at <pfurtscheller@tugraz.at>
Neuper
C
C
Brunner
C
C
da Silva
F Lopes
FL
D000328:Adult; D001611:Beta Rhythm; D001683:Biological Clocks / Q000502:physiology*; D001931:Brain Mapping; D003344:Cortical Synchronization; D003463:Cues; D005071:Evoked Potentials / Q000502:physiology*; D005528:Foot / Q000294:innervation / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000294:innervation / Q000502:physiology; D006801:Humans; D007092:Imagination / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D014059:Tongue / Q000294:innervation / Q000502:physiology