Open AccessRelation between muscle and brain activity during isometric contractions of the first dorsal interosseus muscle
Author(s) -
van Duinen Hiske,
Renken Remco,
Maurits Natasha M.,
Zijdewind Inge
Publication year - 2008
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.20388
Subject(s) - isometric exercise , premotor cortex , inferior parietal lobule , brain activity and meditation , electromyography , neuroscience , psychology , motor cortex , supplementary motor area , coactivation , index finger , superior parietal lobule , precentral gyrus , anatomy , central sulcus , electroencephalography , supramarginal gyrus , brain mapping , physical medicine and rehabilitation , medicine , functional magnetic resonance imaging , dorsum , magnetic resonance imaging , stimulation , radiology
Abstract We studied the relationship between muscle activity (electromyography, EMG), force, and brain activity during isometric contractions of the index finger, on a group and individual level. Ten subjects contracted their right or left index finger at 5, 15, 30, 50, and 70% of their maximal force. Subjects received visual feedback of the produced force. We focused our analysis on brain activation that correlated with EMG. Brain activity of specific anatomical areas (region‐of‐interest analysis, ROI) was quantified and correlated with EMG activity. Furthermore, we tried to distinguish between brain areas in which activity was modulated by the amount of EMG and areas that were active during the task but in which the activity was not modulated. Therefore, we used two regressors simultaneously: (1) the produced EMG and (2) the task (a categorical regressor). As expected, activity in the motor areas (contralateral sensorimotor cortex, premotor areas, and ipsilateral cerebellum) strongly correlated with the amount of EMG. In contrast, activity in frontal and parietal areas (inferior part of the right precentral sulcus, ipsilateral supramarginal gyrus, bilateral inferior parietal lobule, bilateral putamen, and insular cortex) correlated with activation per se, independently of the amount of EMG. Activity in these areas was equal during contractions of the right or left index finger. We suppose that these areas are more involved in higher order motor processes during the preparatory phase or monitoring feedback mechanisms. Furthermore, our ROI analysis showed that muscle and brain activity strongly correlate in traditional motor areas, both at group and at subject level. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.