Title
Functional resting-state connectivity of the human motor network: Differences between right- and left-handers.
Abstract
Handedness is associated with differences in activation levels in various motor tasks performed with the dominant or non-dominant hand. Here we tested whether handedness is reflected in the functional architecture of the motor system even in the absence of an overt motor task. Using resting-state functional magnetic resonance imaging we investigated 18 right- and 18 left-handers. Whole-brain functional connectivity maps of the primary motor cortex (M1), supplementary motor area (SMA), dorsolateral premotor cortex (PMd), pre-SMA, inferior frontal junction and motor putamen were compared between right- and left-handers. We further used a multivariate linear support vector machine (SVM) classifier to reveal the specificity of brain regions for classifying handedness based on individual resting-state maps. Using left M1 as seed region, functional connectivity analysis revealed stronger interhemispheric functional connectivity between left M1 and right PMd in right-handers as compared to left-handers. This connectivity cluster contributed to the individual classification of right- and left-handers with 86.2% accuracy. Consistently, also seeding from right PMd yielded a similar handedness-dependent effect in left M1, albeit with lower classification accuracy (78.1%). Control analyses of the other resting-state networks including the speech and the visual network revealed no significant differences in functional connectivity related to handedness. In conclusion, our data revealed an intrinsically higher functional connectivity in right-handers. These results may help to explain that hand preference is more lateralized in right-handers than in left-handers. Furthermore, enhanced functional connectivity between left M1 and right PMd may serve as an individual marker of handedness.
Year
DOI
Venue
2015
10.1016/j.neuroimage.2015.01.034
NeuroImage
Keywords
Field
DocType
Handedness,Dorsolateral premotor cortex,Inferior frontal gyrus,Support vector machine,Motor asymmetry
Brain mapping,Developmental psychology,Neuroscience,Functional magnetic resonance imaging,Premotor cortex,Resting state fMRI,Psychology,Supplementary motor area,Motor cortex,Motor system,Primary motor cortex
Journal
Volume
ISSN
Citations 
109
1053-8119
3
PageRank 
References 
Authors
0.50
15
5
Name
Order
Citations
PageRank
Eva-Maria Pool1232.83
Anne K Rehme230.50
Simon B. Eickhoff377150.96
Fink Gereon R456355.92
Christian Grefkes551336.31