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Abstract
People construct the meaning of words by relying, in part, on neural systems for perception and action. For instance, when people process language about actions, they show body-part specific activation in premotor circuits used for preparing actions. How does premotor cortex contribute to the meaning of action language? In Study 1, I used fMRI to test whether people rely on different kinds of action experience to understand language about their own actions and other people’s actions. When left- and right-handers imagined their own unimanual actions, they preferentially activated premotor circuits controlling their dominant hand. By contrast, when imagining other people’s actions, premotor activity also reflected how participants typically see others perform those actions. Language-induced imagery for our own actions reflects how we use our own bodies, whereas imagery for others’ actions also reflects how others use their bodies. In Study 2, I show that premotor cortex functionally contributes to how well people process action language. tDCS to premotor hand-areas selectively affected how accurately people processed unimanual action verbs (but not abstract verbs): Inhibitory stimulation caused a relative improvement in how people processed manual action verbs, whereas excitatory stimulation caused a relative impairment. In Study 3, I developed corpora of Dutch and English manual action verbs to quantify how people use their hands to perform the actions described by these verbs, and show how these corpora provide a precision-tool to test whether the way in which people simulate a given action verb reflects how they typically use their body to perform that action.