 This body of research originated so-called simulationist (or enactivist) accounts of conceptual competence, on which “understanding is imagination” and “imagining is a form of simulation” (Gallese &amp; Lakoff 2005). In these accounts, conceptual (often called “semantic”) competence is seen as the ability to simulate or re-enact perceptual (including proprioceptive and introspective) experiences of the states of affairs that language describes, by manipulating memory traces of such experiences or fragments of them. In Barsalou’s theory of perceptual symbol systems (1999), language understanding (and cognition in general) is based on perceptual experience and memory of it. The central claim is that “sensory-motor systems represent not only perceived entities but also conceptualizations of them in their absence”. Perception generates mostly unconscious “neural representations in sensory-motor areas of the brain”, which represent schematic components of perceptual experience. Such perceptual symbols are not holistic copies of experiences but selections of information isolated by attention. Related perceptual symbols are integrated into a simulator that produces limitless simulations of a perceptual component, such as red or lift. Simulators are located in long-term memory and play the roles traditionally attributed to concepts: they generate inferences and can be combined recursively to implement productivity. A concept is not “a static amodal structure” as in traditional, computationally-oriented cognitive science, but “the ability to simulate a kind of thing perceptually”. Linguistic symbols (i.e., auditory or visual memories of words) get to be associated with simulators; perceptual recognition of a word activates the relevant simulator, which simulates a referent for the word; syntax provides instructions for building integrated perceptual simulations, which “constitute semantic interpretations”.