Abstract

The human conceptual system contains categorical knowledge that supports online processing (perception, categorization, inference, action) and offline processing (memory, language, thought). Semantic memory, the dominant theory, typically portrays the conceptual system as modular and amodal. According to this view, amodal symbols represent category knowledge in a modular system, separate from the brain’s modal systems for perception, action, and introspection (e.g., affect, mental states). Alternatively, the conceptual system can be viewed as non-modular and modal, sharing representational mechanisms with the brain’s modal systems. On a given occasion, multimodal information about a category’s members is reenacted (simulated) across relevant modalities to represent it conceptually. Behavioral and neural evidence is presented showing that modal simulations contribute to the representation of object categories, abstract categories, and to the symbolic operations of predication and conceptual combination. Although simulation plays important roles in the conceptual system, linguistic processes are important as well. Additional behavioral and neural evidence is presented showing that simulation and language contribute to conceptual processing simultaneously. Furthermore, either system can dominate under different task conditions, such that different profiles of conceptual processing emerge.