Anatomy and lateralization of the human corticobulbar tracts: an fMRI-guided tractography study

摘要: The left hemisphere lateralization bias for language functions, such as syntactic processing and semantic retrieval, is well known. Although several theories clinical data indicate a link between speech motor execution language, the functional structural brain these functions has never been examined concomitantly in same individuals. Here, we used MRI during rapid silent syllable repetition (/lalala/, /papapa/ /pataka/, known oral diadochokinesis or DDK) to map cortical representation of articulators 17 healthy adults. In participants, production was assessed using well-established verb generation task. We then DDK-related fMRI activation clusters guide tractography corticobulbar tract from diffusion-weighted MRI. Functional revealed wide inter-individual variability hemispheric asymmetry patterns (left right dominant, bilateral) DDK cortex, despite predominantly dominance language-related activity Broca's area. Tractography no evidence (based on fractional anisotropy) within tract. To our knowledge, this study first reveal that unrelated adult humans. addition, found human an asymmetric white matter pathway. suggest predominance dysarthria following infarct probably consequence disrupted feedback input planning regions, rather than itself.