A parietal-frontal network studied by somatosensory oddball MEG responses, and its cross-modal consistency.
Previous studies using functional magnetic resonance imaging (fMRI) and event-related potentials (ERPs) of the brain have found that a distributed parietal-frontal neuronal network is activated in normals during both auditory and visual oddball tasks. The common cortical regions in this network are inferior parietal lobule (IPL)/supramarginal gyrus (SMG), anterior cingulate cortex (ACC), and dorsolateral prefrontal cortex (DLPFC). It is not clear whether the same network is activated by oddball tasks during somatosensory stimulation. The present study addressed this question by testing healthy adults as they performed a novel median-nerve oddball paradigm while undergoing magnetoencephalography (MEG). An automated multiple dipole analysis technique, the Multi-Start Spatio-Temporal (MSST) algorithm, localized multiple neuronal generators, and identified their time-courses. IPL/SMG, ACC, and DLPFC were reliably localized in the MEG median-nerve oddball responses, with IPL/SMG activation significantly preceding ACC and DLPFC activation. Thus, the same parietal-frontal neuronal network that shows activation during auditory and visual oddball tests is activated in a median-nerve oddball paradigm. Regions uniquely related to somatosensory oddball responses (e.g., primary and secondary somatosensory, dorsal premotor, primary motor, and supplementary motor areas) were also localized. Since the parietal-frontal network supports attentional allocation during performance of the task, this study may provide a novel method, as well as normative baseline data, for examining attention-related deficits in the somatosensory system of patients with neurological or psychiatric disorders.
Department of Radiology, University of California, San Diego, 92103-8756, USA. mxhuang@ucsd.edu
Ming-Xiong
MX
Huang
Roland R
RR
Lee
Gregory A
GA
Miller
Robert J
RJ
Thoma
Faith M
FM
Hanlon
Kim M
KM
Paulson
Kimberly
K
Martin
Deborah L
DL
Harrington
Michael P
MP
Weisend
J Christopher
JC
Edgar
Jose M
JM
Canive
D000328:Adult; D003071:Cognition / Q000502:physiology; D004558:Electric Stimulation; D018913:Event-Related Potentials, P300 / Q000502:physiology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D008475:Median Nerve / Q000502:physiology; D009010:Monte Carlo Method; D009415:Nerve Net / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*