In everyday life, our actions are often guided by verbal instructions. Usually, we can implement such instructions immediately without trial and error learning. This raises the fundamental question how verbal instructions are transformed into efficient motor behavior. The aim of this study was to gain deeper insights into the implementation of verbal instructions both on a neural and a cognitive level. To this end, we devised an fMRI experiment in which participants were required to permanently implement new stimulus-response (S-R) mappings and object-color (O-C) mappings. This enabled us to test whether there are brain areas that are specific to the implementation of newly instructed S-R mappings or whether newly instructed rules are represented independently from the specific content. Furthermore, we could test which brain areas are involved in the processing of S-R mappings when compared with O-C mappings. Our results suggest that only one brain area, the left inferior frontal junction (IFJ), was sensitive to the novelty of instructions regardless of whether these instructions conveyed S-R or O-C mappings. Furthermore, our results show that instructions conveying S-R mapping involve a network of brain areas, including pre-PMd, M1, and IPS that was not sensitive to the novelty of the instructions. Therefore, we conclude that the implementation of verbal instructions results from an interplay of a brain areas that represent novel rulelike information in domain general terms and brain areas that are specific to S-R rules.

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In the last decade, research on error and conflict processing has become one of the most influential research areas in the domain of cognitive control. There is now converging evidence that a specific part of the posterior frontomedian cortex (pFMC), the rostral cingulate zone (RCZ), is crucially involved in the processing of errors and conflict. However, error-related research has focused primarily on a specific error type, namely, response errors. The aim of the present study was to investigate whether errors on the task level rely on the same neural and functional mechanisms. Here we report a dissociation of both error types in the pFMC: whereas response errors activate the RCZ, task errors activate the dorsal frontomedian cortex. Although this last region shows an overlap in activation for task and response errors on the group level, a closer inspection of the single-subject data is more in accordance with a functional anatomical dissociation. When investigating brain areas related to conflict on the task and response levels, a clear dissociation was perceived between areas associated with response conflict and with task conflict. Overall, our data support a dissociation between response and task levels of processing in the pFMC. In addition, we provide additional evidence for a dissociation between conflict and errors both at the response level and at the task level.

Abstract■ Verbal instructions are central to humans' capacity to learn new behaviors with minimal training, but the neurocognitive mechanisms involved in verbally instructed behaviors remain puzzling. Recent functional magnetic resonance imaging (fMRI) evidence suggests that the right middle frontal gyrus and dorsal premotor cortex (rMFG-dPMC) supports the translation of symbolic stimulus-response mappings into sensorimotor representations. Here, we set out to (1) replicate this finding, (2) investigate whether this region's involvement is specific to novel (vs. trained) instructions, and (3) study whether rMFG-dPMC also shows differences in its (voxel) pattern response indicative of general cognitive processes of instruction implementation. Participants were shown instructions, which they either had to perform later or merely memorize. Orthogonal to this manipulation, the instructions were either entirely novel or had been trained before the fMRI session. Results replicate higher rMFG-dPMC activation levels during instruction implementation versus memorization and show how this difference is restricted to novel, but not trained, instruction presentations. Pattern similarity analyses at the voxel level further reveal more consistent neural pattern responses in rMFG-dPMC during the implementation of novel versus trained instructions. In fact, this more consistent neural pattern response seemed to be specific to the first instruction presentation and disappeared after the instruction had been applied once. These results further support a role of rMFGdPMC in the implementation of novel task instructions and highlight potentially important differences in studying this region's gross activation levels versus (the consistency of ) its response patterns. ■

Decision-making involves the ability to choose between competing actions that are associated with uncertain benefits and penalties. The Iowa Gambling Task (IGT), which mimics real-life decision-making, involves learning a reward-punishment rule over multiple trials. Patients with damage to ventromedial prefrontal cortex (VMPFC) show deficits learning these rules, although this performance deficit is not exclusively associated with VMPFC damage. In this study, we used functional Magnetic Resonance Imaging to study the roles of prefrontal cortex regions involved in rule learning and rule application in healthy adults using an adapted version of the Iowa Gambling Task. Participants (N =20) were asked to infer rules over series of 16 trials in a two-deck card game. Rewards were given on each trial and punishment was unpredictable. For half of the series, those decks that gave high rewards were also better decks in the long run. For the other half of the series, the decks that gave low rewards were better decks in the long run. Behaviorally, participants started to differentiate between advantageous and disadvantageous decks after approximately four/six trials, and learning occurred faster for high-reward decks. Lateral PFC (lat-PFC) and Anterior Cingulate Coretex (ACC)/pre-Supplementary Motor Area (pre-SMA) were most active for early decisions, whereas medial orbital frontal cortex (med-OFC) was most active for decisions made later in the series. These results suggest that lat-PFC and ACC/pre-SMA are important for directing behavior towards long-term goals, whereas med-OFC represents reward values towards which behavior should be directed.