Influential theories of complex behaviour invoke the notion of cognitive control modulated by conflict between counterfactual actions. Medial frontal cortex, notably the anterior cingulate cortex, has been variously posited as critical to such conflict detection, resolution, or monitoring, largely based on correlative data from functional imaging. Examining performance on the most widely used “conflict” task—Stroop—in a large cohort of patients with focal brain injury (N = 176), we compare anatomical patterns of lesion-inferred neural substrate dependence to those derived from functional imaging, meta-analytically summarised. Our results show that whereas performance is sensitive to the integrity of left lateral frontal regions implicated by functional imaging, it does not depend on medial frontal cortex, despite sampling adequate to reveal robust medial effects in the context of phonemic fluency. We suggest that medial frontal cortex is not critically invoked by Stroop and proceed to review the conceptual grounds for rejecting the core notion of conflict-driven cognitive control.

The brain builds and maintains internal models and uses them to make predictions. When predictions are violated, the current model can either be updated or replaced by a new model. The latter is accompanied by pupil dilation responses (PDRs) related to locus coeruleus activity/norepinephrine release (LC-NE). Following earlier research, we investigated PDRs associated with transitions between regular and random patterns of tones in auditory sequences. We presented these sequences to participants and instructed them to find gaps (to maintain attention). Transitions from regular to random patterns induced PDRs, suggesting that an internal model attuned to the regular pattern is reset. Transitions from one regular pattern to another regular pattern also induced PDRs, suggesting that they also led to a model reset. In contrast, transitions from random patterns to regular patterns did not induce PDRs, suggesting a gradual update of model parameters. We modelled these findings, using pupil response functions to show how ongoing PDRs and pupil event rates were sensitive to the trial-by-trial changes in the information content of the auditory sequences. Expanding on previous research, we suggest that PDRs—as biomarkers for LC-NE activation—may indicate the extent of prediction violations.

Recurring utterances (RUs) are a distinct language symptom observed in severe aphasia, known to be associated with global or Broca’s aphasia, though their neural basis remains unclear. We present a case of RU induced by selective left frontal suppression using a novel technique named the super-selective Wada test (ssWada), which involves temporary anesthetization of specific brain regions through super-selective catheterization of cerebral arteries. This method allows for precise simulation of localized brain dysfunction. We applied this technique on a 49-year-old right-handed man with drug-resistant epilepsy as a preoperative examination. Propofol administration to the superior branch of the left middle cerebral artery (MCA), supplying the pars triangularis, pars opercularis, middle frontal gyrus, and part of the precentral gyrus, induced Broca’s aphasia with RUs. The RU content was the phrase uttered at anesthesia administration. Notably, the anesthetic did not affect the temporal language area or basal ganglia. The patient showed minimal awareness of his abnormal speech despite preserved receptive language function and memory, aligning with previous observations of anosognosia in patients with RU. Contrastingly, anesthetic infusion into the inferior branch of the left MCA resulted in mixed aphasia, while right MCA infusion induced no language impairments. This case demonstrates that RUs can arise without deficits in the posterior language area or basal ganglia. It illustrates the potential of ssWada in investigating neural substrates of neuropsychological symptoms through temporary, localized brain disruption. This approach offers novel insights into brain-behavior relationships in language processing and cognition.

Previous studies indicated that the sense of body ownership (i.e., the feeling that our body parts belong to us; SBO) can be experimentally modulated in humans. Here, we focused on SBO from an across-species perspective, by investigating whether similar bottom-up and top-down constraints that consent to build SBO in humans also operate to build it in monkeys. To this aim, one monkey and a cohort of humans (N = 20) performed a paradigm combining the well-known rubber hand illusion (RHI), able to induce a fake hand embodiment, and a hand-identification reaching task, borrowed from the clinical evaluation of patients with SBO disorders. This task consisted of reaching one’s own hand with the other, while presenting a fake hand in different conditions controlling for bottom-up (synchronicity of the visuo-tactile stimulation) and top-down (congruency of the fake hand position relative to the monkey’s body) SBO constraints. Spatiotemporal kinematic features of such self-directed movements were measured. Our results show that, when the monkey aimed at the own hand, the trajectory of self-directed movements was attracted by the position of the hand believed to be one’s own (i.e., the fake hand), as in humans. Interestingly, such an effect was present only when both bottom-up and top-down constraints were met. Moreover, in the monkey, besides displacement of movement trajectory, also other kinematic parameters (velocity peak, deceleration phase) showed sensitivity to the embodiment effect. Overall, if replicated in a larger sample of monkeys, these results should support the view that human and non-human primates share similar body representation constraints and that they are able to modulate the motor behavior in both species.