The Neuroscience of Language

This chapter reviews how the brain represents concepts and word meanings, often termed semantic memory. A long history of work in people with focal brain damage suggests that different categories of concepts (for example, inanimate objects vs. living things) rely on different parts of the brain, evidenced by category-specific deficits in semantic memory. The notion of distributed semantic representations is further supported by studies showing activations for different concepts relying on different parts of the brain. In addition, there is evidence for unified semantic representations – that is, brain regions that play a role in representing a wide variety of concepts. These include the angular gyrus (active in many functional neuroimaging studies of semantic memory) and portions of the anterior temporal lobe (damage to which in the semantic variant of primary progressive aphasia). Together, frameworks that include a “hub-and-spoke” arrangement – which allow both for regions that are important for many concepts (hubs) and those representing modality-specific information (spokes) – may provide the most comprehensive view of how concepts are represented.