Neurobiology of specific language impairment.

This review summarizes what is known about the neurobiology of specific language impairment. Despite its name, specific language impairment is frequently not specific. It is common to find associated impairments in motor skills, cognitive function, attention, and reading in children who meet criteria for specific language impairment. There is evidence that limitation in phonologic working memory may be a core deficit in specific language impairment. Both genetic and environmental factors have been shown to be important etiologic factors in specific language impairment. Structural neuroimaging studies suggest that atypical patterns of asymmetry of language cortex, white-matter abnormalities, and cortical dysplasia may be associated with specific language impairment. Abnormalities in the later stages of auditory processing have been demonstrated using auditory event-related potentials. Functional neuroimaging may cast further light on the neurobiology of specific language impairment and serve as a means of developing and evaluating therapy. A better understanding of the neurobiology of specific language impairment is critical for the rational development of therapeutic strategies to treat this common disorder.