Cortical activation associated with passive movements of the human index finger: an MEG study.
We recorded somatosensory evoked fields to passive extensions of the left and right index fingers in eight healthy adults. A new nonmagnetic device was designed to produce calibrated extensions of 19 degrees, with a mean angular velocity of 630 degrees/s. The responses, recorded with a 306-channel neuromagnetometer, were modeled with current dipoles. The earliest activation was in the primary somatosensory cortex, with peaks at 36-58 and 30-82 ms for left and right index finger extensions, respectively. Later signals were observed in the left second somatosensory (SII) cortex in six of eight subjects at 75-175 and 75-155 ms for left- and right-sided extensions, respectively; three subjects showed bilateral SII activation in at least one condition. Our results suggest a predominant role for the human left SII cortex in proprioceptive processing.
Alary
F
F
Brain Research Unit, Low Temperature Laboratory, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT, Espoo, Finland.
Simões
C
C
Jousmäki
V
V
Forss
N
N
Hari
R
R
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000294:innervation*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D011434:Proprioception / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted