Semantic Hubs

Chapter 4 turns to the so-called general semantic network (GSN), which consists of several very high-level, interconnected cortical areas that are considered transmodal because they operate on two or more types of sensory/motor information. Mounting evidence suggests that the GSN contributes to word meanings by performing a variety of integrative and relational functions. Continuing with the example of scissors, the GSN conjoins its distinctive experiential features (which, as noted above, are housed in modal networks of sensory/motor areas), assembles them into a coherent concept that can easily be accessed during language production and comprehension, situates this particular concept in relation to many others, and connects it with personal memories and attitudes (e.g., using one’s favorite pair of scissors in an enjoyable project). As we’ll see, one of the most fascinating properties of the GSN is that it overlaps substantially with the well-studied default mode network (DMN), which mediates internally oriented mental processes such as recalling one’s past, imagining one’s future, simulating dialogues, and contemplating other people’s thoughts and feelings – all of which require semantic cognition.