Delineating the functional organization of the prefrontal cortex is central to advancing models of goal-directed cognition. Considerable evidence indicates that specific forms of cognitive control are associated with distinct subregions of the left ventrolateral prefrontal cortex (VLPFC), but less is known about functional specialization within the right VLPFC. We report a functional MRI meta-analysis of two prominent theories of right VLPFC function: stopping of motor responses and reflexive orienting to abrupt perceptual onsets. Along with a broader review of right VLPFC function, extant data indicate that stopping and reflexive orienting similarly recruit the inferior frontal junction (IFJ), suggesting that IFJ supports the detection of behaviorally relevant stimuli. By contrast, other right VLPFC subregions are consistently active during motor inhibition, but not reflexive reorienting tasks, with posterior-VLPFC being active during the updating of action plans and mid-VLPFC responding to decision uncertainty. These results highlight the rich functional heterogeneity that exists within right VLPFC.

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Understanding the neural basis of conscious experience and its regulation are fundamental goals of science. While recent research has made substantial progress in identifying the neural correlates of conscious experiences, it remains unclear how individuals exert control over the contents of awareness. In particular, can a memory that has entered the aware state be purged from consciousness if it is not currently desired? Here we tracked the correlates of consciousness in humans using fMRI and demonstrated the involvement of a down-regulation mechanism that purges contents from conscious awareness. When individuals tried to prevent the retrieval of a memory in response to reminders, hippocampal activity was reduced, as previously established. Crucially, using trial-by-trial reports of phenomenal awareness, we found that this reduction of hippocampal activation was specifically associated with moments when a memory involuntarily intruded into conscious awareness and needed to be purged. This down-regulation of activity during memory intrusions appears to disrupt momentary awareness of unwanted contents and, importantly, predicts impaired recall of the memory on later tests. These results tie the voluntary control of phenomenal awareness to observable changes in neural activity linked to awareness, and so provide a neurobiological model for guiding inquiry into the physical foundations of control over consciousness.

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