Functional hemispheric asymmetries of speech production and perception are a key feature of the human language system, but their relation to microstructural asymmetries in language-relevant white matter pathways is still poorly understood. In the present study, a team of neuroscientists from the Institute of Cognitive Neuroscience and the Bergen fMRI Group, Norway, used a combined fMRI and tract-based spatial statistics approach to investigate this question. Tract-based spatial statistics revealed several leftward asymmetric clusters in the arcuate fasciculus and uncinate fasciculus that were differentially related to functional language asymmetries. These findings suggest that white matter asymmetries may indeed be one of the factors underlying functional hemispheric asymmetries.

Ocklenburg, S., Hugdahl, K., Westerhausen, R. (2013). Structural white matter asymmetries in relation to functional asymmetries during speech perception and production. Neuroimage, 83, 1088-1097