Language

Language, speech, and semantic knowledge are fundamental cognitive functions critical for human communication and knowledge of the world. Language comprehension and production involve core areas in the left temporoparietal cortex and inferior frontal gyrus that participate in separate but interacting networks for semantic and syntactic processing. Voice and speech production are controlled by separate corticobulbar systems that are hierarchically organized. Semantic knowledge about world objects and their action primarily involves ventrolateral portions of the anterior temporal lobe. Disturbances of these processes manifest with different forms of primary progressive aphasia, apraxia of speech, or semantic variant primary progressive aphasia.