ABSTRACT
The human conceptual system contains knowledge about the world that
supports categorical inference, conceptual combination, and basic
cognitive tasks (e.g., perception, memory, language, thought).
Standard views of semantic memory typically portray the conceptual
system as modular, amodal, static, abstractive, and taxonomic.
Recent connectionist accounts are dynamic and contextual but often
remain modular, amodal, and taxonomic (although not necessarily
so). An alternative view is presented, along with supporting
empirical evidence. On this view, the conceptual system shares
representational mechanisms with sensory-motor systems, thereby
making it non-modular and modal. Within this framework, simulators
represent a category dynamically by constructing diverse
simulations of category instances across occasions (i.e., static
concepts do not represent categories). To represent a category on a
given occasion, a simulator reenacts a small subset of modal
information for the category. In addition, these simulations
include knowledge about settings, actions, and mental perspectives,
thereby contextualizing the category's representations. Finally,
systems of categories are organized to support situated action. Ad
hoc categories arise at the interface between action sequences and
the world, with taxonomic categories being subsidiary to this
interface. Behavioral and neural evidence is presented to support
this view of the conceptual system.