Cognition and medial frontal cortex in health and disease.

Recent work on the role of the medial frontal cortex in cognition and its involvement in neurological disorders is critically reviewed. The highly influential notion of conflict monitoring by the anterior cingulate has been called into question by monkey single-cell neurophysiology and lesion studies in monkeys and humans. An alternative role for this region in adapting behaviour in response to changing demands over time is gaining support. By contrast, the more dorsally placed presupplementary motor area and supplementary eye field have been implicated in direct executive control in situations of response conflict. Although more rostral medial areas have been linked to complex cognitive operations involving references to the self, conceptual obstacles make the evidence difficult to interpret. The role of the orbitofrontal cortex in guiding action based on value has been reinforced. The role of the medial frontal cortex in cognition continues to generate both interest and controversy. A few striking discrepancies between data from functional imaging and interventional techniques illustrate the hazards of drawing strong conclusions from merely correlative evidence. More broadly, a case can be made for tempering the empirical enthusiasm here with a little more theoretical restraint.