Title
Hemispheric asymmetries in language-related pathways: a combined functional MRI and tractography study.
Abstract
Functional lateralization is a feature of human brain function, most apparent in the typical left-hemisphere specialization for language. A number of anatomical and imaging studies have examined whether structural asymmetries underlie this functional lateralization. We combined functional MRI (fMRI) and diffusion-weighted imaging (DWI) with tractography to study 10 healthy right-handed subjects. Three language fMRI paradigms were used to define language-related regions in inferior frontal and superior temporal regions. A probabilistic tractography technique was then employed to delineate the connections of these functionally defined regions. We demonstrated consistent connections between Broca's and Wernicke's areas along the superior longitudinal fasciculus bilaterally but more extensive fronto-temporal connectivity on the left than the right. Both tract volumes and mean fractional anisotropy (FA) were significantly greater on the left than the right. We also demonstrated a correlation between measures of structure and function, with subjects with more lateralized fMRI activation having a more highly lateralized mean FA of their connections. These structural asymmetries are in keeping with the lateralization of language function and indicate the major structural connections underlying this function.
Year
DOI
Venue
2006
10.1016/j.neuroimage.2006.03.011
NeuroImage
Keywords
Field
DocType
fractional anisotropy,left hemisphere
Developmental psychology,Neuroscience,Lateralization of brain function,Planum temporale,Extreme capsule,Fractional anisotropy,Diffusion Tractography,Superior longitudinal fasciculus,Cognitive psychology,Psychology,Arcuate fasciculus,Tractography
Journal
Volume
Issue
ISSN
32
1
1053-8119
Citations 
PageRank 
References 
37
2.39
9
Authors
10
Name
Order
Citations
PageRank
H. W. Robert Powell1372.39
Geoffrey J. M. Parker244439.62
Daniel C. Alexander31553144.96
Mark R. Symms413811.94
Philip A. Boulby5393.09
C. A. Wheeler-kingshott660553.32
Gareth J Barker729936.37
U. Noppeney812933.46
Matthias J. Koepp9635.19
J S Duncan1036838.49