Proceedings of the Annual Meeting of the Cognitive Science Society

Knowledge affects how humans think and reason: people use background knowledge to interpret natural language, and reason over those interpretations. We show one way in which offline knowledge, which is stored in semantic memory, interacts with online knowledge, that is, knowledge acquired through the use of factive mental state verbs such as know and discover. The interaction tests a theory of human thinking that assumes people construct simulations of possibilities – mental models – when they reason. It predicts that offline knowledge can affect reasoning through a process known as modulation, which blocks the mental construction of possibilities; and that online knowledge can cause reasoners to make presuppositions about facts. It also describes the mechanisms by which the mind updates mental models and separates fact from belief. An experiment tested the theory and corroborated its predicted interaction effect. We discuss the results in light of recent proposals of reasoning with knowledge.