On-line Changing of Thinking about Words: The Effect of Cognitive Context on Neural Responses to Verb Reading Liuba Papeo 1,3,4 , Raffaella Ida Rumiati 1 , Cinzia Cecchetto 1 , and Barbara Tomasino 2 Abstract ■ Activity in frontocentral motor regions is routinely reported when individuals process action words and is often interpreted as the implicit simulation of the word content. We hypothesized that these neural responses are not invariant components of action word processing but are modulated by the context in which they are evoked. Using fMRI, we assessed the relative weight of stimulus features (i.e., the intrinsic semantics of words) and contextual factors, in eliciting word-related sensori- motor activity. Participants silently read action-related and state verbs after performing a mental rotation task engaging either a motor strategy (i.e., referring visual stimuli to their own bodily movements) or a visuospatial strategy. The mental rotation tasks were used to induce, respectively, a motor and a non- motor “cognitive context” into the following silent reading. Irrespective of the verb category, reading in the motor context, compared with reading in the nonmotor context, increased the activity in the left primary motor cortex, the bilateral premotor cortex, and the right somatosensory cortex. Thus, the cogni- tive context induced by the preceding motor strategy-based mental rotation modulated word-related sensorimotor re- sponses, possibly reflecting the strategy of referring a word meaning to oneʼs own bodily activity. This pattern, common to action and state verbs, suggests that the context in which words are encountered prevails over the intrinsic semantics of the stimuli in mediating the recruitment of sensorimotor regions. ■ INTRODUCTION The context of a cognitive task corresponds to any external information that channels an individualʼs attention to cer- tain aspects of the stimuli, thus guiding the subsequent information process. The internal representation of a con- text helps generate predictions about the content of stimuli and update task-relevant information for the selection of a response (Fenske, Aminoff, Gronau, & Bar, 2006; Friston, 2003; Büchel & Friston, 1997; Cohen, Servan-Schreiber, & McClelland, 1992). The implication of such top–down modulation of stimulus processing is striking: Neural re- sponses are not invariant to a stimulus and, depending on the context in which they are evoked, differential activity can relate to the processing of identical stimuli (Friston, 2003). This defines the notion of modulability and reversibil- ity of the modality (or strategy) for processing information. The role of bottom–up and top–down factors has been highlighted in studies addressing whether the recruit- ment of motor processes in mental rotation depends, re- spectively, on the nature of the stimuli or on the particular mental operation adopted for solving a task. Top–down control has been examined through the implicit transfer of strategies, a phenomenon occurring when a processing mode is implicitly transferred from one task to another that does not necessarily require it (Wraga, Thompson, Alpert, & Kosslyn, 2003; Grafton, Fagg, & Arbib, 1998; Pascual-Leone, Grafman, & Hallet, 1994; Willingham, Greeley, & Bardone, 1993). In particular, Wraga et al. (2003) showed that mental rotation of objects, known to rely on visuospatial processing or visuospatial strategy (Zacks, 2008), elicited motor activity when participants had previously performed mental rotation of hands, a task found to engage motor processes or motor strategy (i.e., the internal rotation of oneʼs own hand; Kosslyn, Ganis, & Thompson, 2001; Ganis, Keenan, Kosslyn, & Pascual- Leone, 2000; Bonda, Petrides, Frey, & Evans, 1995; Parsons et al., 1995). That is, because of the implicit transfer of the motor strategy used during the hand rotation task, partici- pants imagined grasping and rotating objects with their own hands. No motor activity was found when object rota- tion was not preceded by the hand rotation task. Adopting a strategy to perform a Task A can thus implicitly evoke a “cognitive context” that affects neural responses to a subsequent Task B. We exploited this cognitive phenomenon to contribute to the current debate on word processing. It has been proposed that processing words denoting motor acts in- volves accessing stored sensorimotor information (Binder 1 SISSA, Area of Neuroscience, Trieste, Italy, 2 I.R.C.C.S. “E. Medea,” San Vito al Tagliamento, Italy, 3 Harvard University, 4 University of Trento © 2012 Massachusetts Institute of Technology Journal of Cognitive Neuroscience 24:12, pp. 2348–2362