Researchers at University Hospital, Rennes, France compared functional MRI studies of 21 children with developmental dysphasia and matched controls using a panel of four language tests including auditory and visual tasks. Children with specific language impairment exhibited a significant lack of left lateralization in core language regions (inferior frontal gyrus-opercularis, inferior frontal gyrus-triangularis, supramarginal gyrus and superior temporal gyrus). Between group comparisons revealed a left hypoactivation of Wernicke’s area during the responsive naming task, and a right hyperactivation of the anterior insula, inferior frontal gyrus and head of caudate during a phonological task. Developmental dysphasia is associated with atypical lateralization and functioning of core language areas. [1]
COMMENT. The etiology of specific language impairment is unclear; an interaction between genes and environmental risk factors may affect the anatamo-functional development and organization of the brain language network (Rapin I et al, 2003). fMRI and other studies show that an abnormality of brain development is bilateral and not confined to the left hemisphere.