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| Research article summary (published 30 Aug 2002): |
Generators of movement-related cortical potentials: fMRI-constrained EEG dipole source analysis.
Full Abstract
To clarify the precise location and timing of the mo tor cortical activation in voluntary movement, dipole source analysis integrating multiple constraints wa conducted for the movement-related cortical potentia (MRCP). Six healthy subjects performed single self paced extensions of the right index finger at about 15-intervals during EEG and event-related fMRI acquisi tions. EEG was recorded from 58 scalp electrodes, and fMRI of the entire brain was obtained every 2.6 s. Coordinates of the two methods were coregistered us ing anatomical landmarks. During dipole source mod eling, a realistic three-layer head model was used as a volume conductor. To identify the number of uncorre lated source s in the MRCP, principal component (PC analysis was performed, which was consistent with the existence of six sources in the left (Lt SM1) and right (Rt SMI) sensorimotor and medial frontocentral (MFC) areas. After dipoles were seeded at the acti vated spots revealed by fMRI, dipole orientations were fixed based on the interpretation of the topography of distribution of the PC. The strength of the six dipoles (three dipoles in Lt SMI, two in Rt SMI, and one in MFC) was then computed over time. Within the bilat eral SM1, activation of the precentral gyrus occurs bilaterally with similar strength from -1.2 s, followed by that of the precentral bank from -0.5 s with con tralateral preponderance. Subsequently, the postcen tral bank becomes active only on the contralateral side at 0.1 s after movement. Activation of the MFC shows timing similar to that of the bilateral precentral gyri These deduced patterns of activation are consis tent with previous studies of electrocorticography in humans.
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Author information
Author/s: Toma, Keiichiro (K); Matsuoka, Takahiro (T); Immisch, Ilka (I); Mima, Tatsuya (T); Waldvogel, Daniel (D); Koshy, Benjamin (B); Hanakawa, Takashi (T); Shill, Holly (H); Hallett, Mark (M);
Affiliation: Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-1428, USA.
Journal and publication information
Publication Type: Clinical Trial; Journal Article
Journal: NeuroImage (Neuroimage), published in United States. (Language: eng)
Reference: 2002-Sep; vol 17 (issue 1) : pp 161-73
Dates: Created 2002/12/16; Completed 2003/01/14; Revised 2004/11/17;
PMID: 12482074, status: MEDLINE (last retrieval date: 11/6/2008)
Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.
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