The human ability to infer other people's knowledge and beliefs, known as 'theory of mind', is an essential component of social interactions. Theory of mind tasks activate frontal and temporoparietal regions of cortex in fMRI studies. However, it is unknown whether these regions are critical. We examined this question using multivariate voxel-based lesion symptom mapping in 22 patients with acute right hemisphere brain damage. Studies of acute patients eliminate questions of recovery and reorganization that plague long-term studies of lesioned patients. Damage to temporoparietal and inferior frontal regions impaired thinking about others' perspectives. This impairment held even after adjustment for overall extent of brain damage and language comprehension, memory, comprehension, and attention abilities. These results provide evidence that right temporoparietal and inferior frontal regions are necessary for the human ability to reason about the knowledge and beliefs of others.

When naming an object, humans are faster to produce the name ("cat") if immediately having named a related object ("dog") but paradoxically slower to name the same object ("cat") if there are intervening speech acts (Wei and Schnur 2019). This dependence of behavior on prior experience is ubiquitous in other domains, often termed "priming" (if behavior is speeded) or "interference" (if behavior is slower). However, it is unknown the changes in the language system (conceptual, lexical, and/or connections between representations) and corresponding brain mechanisms which create these paradoxical effects on the same speech act. Using fMRI during simple picture naming, we observed distinct brain regions and different connections associated with priming and interference. Greater priming was associated with increased activation in the ventral occipitotemporal cortex, while greater interference was associated with decreased functional connectivity between the left posterior temporal and angular gyri. To provide neural evidence of where in the language system priming and interference in naming occur, we assayed the response of different brain areas to conceptual or lexical aspects of speech. The brain and language systems adapt to prior naming experience by modulating conceptual representations during priming, but modulating conceptual, lexical and the mapping between representations during interference. BRAIN DYNAMICS OF PRIMING AND INTERFERENCE DURING NAMING 3 2019). Intriguingly, future word production is slowed down in almost identical circumstances (e.g., Brown 1981;Wheeldon and Monsell 1994;Damian et al. 2001;Howard et al. 2006;Schnur et al. 2006;Vitkovitch et al. 2006;Belke 2013). Recently, using a simple withinsubject and within-item single picture naming task we demonstrated that the emergence of priming or interference in word production depends on the interval between two naming occurrences (Wei and Schnur 2019). To address the neural and cognitive changes responsible for this paradoxical naming phenomenon, in the current study we combined task functional and connectivity magnetic resonance imaging (MRI) with a linguistic assay approach. To our knowledge, this study is the first to identify within the same participants, items, and task how BRAIN DYNAMICS OF PRIMING AND INTERFERENCE DURING NAMING 4 the language system and supporting brain mechanisms change to produce faster or slower speech.In cognitive models of language production, priming and interference are generally assumed to occur at different levels of processing during word production (e.g., Dell 1986;Caramazza 1997;Levelt et al. 1999). That producing a word is sped up or slowed down suggests that different processes during word production are affected by prior naming experience. Just like priming widely reported in other language tasks is hypothesized to occur during access to word meanings (word reading, e.g., Meyer et al. 1975; lexical decision (a decision as to whether a string of letters is a word or not), Meyer and Schvaneveldt 1971; conceptua...