Impaired conflict adaptation in an emotional task context following rostral anterior cingulate cortex lesions in humans.

Recent brain imaging studies have implicated the rostral ACC (rACC) in the resolution of conflict between competing response tendencies in emotional task contexts, but not in neutral task contexts. This study tested the hypothesis that the rACC is necessary for such context-specific conflict adaptation. To this end, a group of patients with lesions of the rACC, a group of brain-damaged controls, and a group of normal controls classified the emotional expression (emotional task context) or the gender (neutral task context) of faces while ignoring congruent and incongruent words written across the faces. In all three groups, performance was worse with incongruent as compared with congruent stimuli in both task contexts. In the two control groups, this congruency effect was reduced following incongruent trials in both task contexts. By contrast, the rACC group displayed such conflict adaptation only in the neutral, but not in the emotional, task context. These results show that the rACC is necessary for conflict adaptation in emotional but not in neutral task contexts and suggest that the regulation of behavior is context specific.