12 - Language

Summary

This chapter describes the neuroanatomy of language beginning with the foundation in the classical lesion model and concludes with an updated view of language-brain organization. Clinical aphasia or language impairments from brain lesions have been the window to localization of language in the brain. The neuropathologic lesion underlying transcortical sensory aphasia is in the left angular gyrus in the parietal region or in the left posterior superior or middle temporal gyri. Language impairment from the basal ganglia may resemble transcortical motor aphasia. Individuals with Paul Broca's aphasia demonstrate comprehension impairments and difficulty integrating words into the context of a sentence. In Karl Wernicke's aphasia, content words tend to be absent or replaced by general terms or associations based on context. Current information modifies the classical Wernicke-Geschwind model of language to incorporate the contributions of perisylvian processing hubs that participate in sequential, neurocomputational operations on language-related information.