One of the least well understood regions of the human brain is rostral prefrontal cortex, approximating Brodmann's area 10. Here, we investigate the possibility that there are functional subdivisions within this region by conducting a meta-analysis of 104 functional neuroimaging studies (using positron emission tomography/functional magnetic resonance imaging). Studies involving working memory and episodic memory retrieval were disproportionately associated with lateral activations, whereas studies involving mentalizing (i.e., attending to one's own emotions and mental states or those of other agents) were disproportionately associated with medial activations. Functional variation was also observed along a rostral-caudal axis, with studies involving mentalizing yielding relatively caudal activations and studies involving multiple-task coordination yielding relatively rostral activations. A classification algorithm was trained to predict the task, given the coordinates of each activation peak. Performance was well above chance levels (74% for the three most common tasks; 45% across all eight tasks investigated) and generalized to data not included in the training set. These results point to considerable functional segregation within rostral prefrontal cortex.

There is converging evidence that the observation of an action activates a corresponding motor representation in the observer through a 'mirror-matching' mechanism. However, research on such 'shared representations' of perception and action has widely neglected the question of how we can distinguish our own motor intentions from externally triggered motor representations. By investigating the inhibition of imitative response tendencies, as an index for the control of shared representations, we can show that self -other distinction plays a fundamental role in the control of shared representations. Furthermore, we demonstrate that overlapping brain activations can be found in the anterior fronto-median cortex (aFMC) and the temporo-parietal junction (TPJ) area for the control of shared representations and complex social-cognitive tasks, such as mental state attribution. In a functional magnetic resonance imaging experiment, we functionally dissociate the roles of TPJ and aFMC during the control of shared representations. Finally, we propose a hypothesis stating that the control of shared representations might be the missing link between functions of the mirror system and mental state attribution.

In our daily life, we continuously monitor others' behaviors and interpret them in terms of goals, intentions, and reasons. Despite their central importance for predicting and interpreting each other's actions, the functional mechanisms and neural circuits involved in action understanding remain highly controversial. Two alternative accounts have been advanced. Simulation theory assumes that we understand actions by simulating the observed behavior through a direct matching process that activates the mirror-neuron circuit. The alternative interpretive account assumes that action understanding is based on specialized inferential processes activating brain areas with no mirror properties. Although both approaches recognize the central role of contextual information in specifying action intentions, their respective accounts of this process differ in significant respects. Here, we investigated the role of context in action understanding by using functional brain imaging while participants observed an unusual action in implausible versus plausible contexts. We show that brain areas that are part of a network involved in inferential interpretive processes of rationalization and mentalization but that lack mirror properties are more active when the action occurs in an implausible context. However, no differential activation was found in the mirror network. Our findings support the assumption that action understanding in novel situations is primarily mediated by an inferential interpretive system rather than the mirror system.

Action observation leads to the automatic activation of the corresponding motor representation in the observer through "mirror-matching." This constitutes a "shared representational system," which is thought to subserve social understanding by motor simulation. However, it is unclear how these shared representations can be controlled and distinguished. Brain imaging suggests that controlling shared representations, indexed by the ability to control automatic imitative responses, activates anterior fronto-median cortex (aFMC), and temporo-parietal junction (TPJ). Crucially, these regions are also consistently implicated in mental state attribution and have provided an alternative account for higher-level social cognition. Here, we directly tested whether social-cognitive processes involve similar key computational mechanisms as the control of shared representations by using functional brain imaging to reveal overlapping brain circuits. We show in a within-subject design that commonly activated regions occurred selectively in aFMC and TPJ. Mentalizing and self-referential thoughts recruited a region in aFMC, which was also activated when controlling imitation. In the TPJ, an area overlapped between mentalizing, agency processing, and imitative control. Behavioral and neural correlates of mentalizing were further related to the individual ability for controlling imitation. Our findings support the assumption of shared key processes and suggest a novel link between embodied and social cognition.