Conflict adaptation in generalized anxiety disorder: small paradigm twist, large scientific leap.

In this issue of the Journal, Etkin and colleagues (1) have published a functional MRI (fMRI) study of implicit affective regulation in health and anxiety that is both provocative and exciting. Provocative because it demonstrates that the elusive process of implicit emotion regulation may be measurable, and exciting because this approach is applied to a clinical question. The study examines the effects of trial repetition on task performance, particularly for trials with conflicting information. This work relies on more than a decade of research investigating " the conflict monitoring theory " (2). This theory posits that the resolution of a conflict—defined as the concomitant presence of stimuli calling for incompatible responses—requires initial detection of the conflict as well as its subsequent resolution. The detection site resides in medial prefrontal structures, including the dorsal anterior cingulate cortex extending dorsally to premotor regions. Once activated, the detection system alerts a cognitive control system that initiates conflict resolution by modulating information processing, i.e., facilitating the processing of the appropriate response while hampering the processing of the incorrect, conflictual, response. The resolution site resides in regions of the dor-solateral prefrontal cortex. The modulated information processing streams lay in posterior brain regions (e.g., the parietal cortex), which are dedicated to sensory-perceptual integration. The study by Etkin and colleagues draws on the critical observation that performance in a conflict trial is influenced by the level of conflict present in the preceding trial. Specifically, performance on a conflict trial is facilitated when preceded by a similar conflict trial. This effect, which relies upon small behavioral adjustments, has been called conflict adaptation (3). The paradigm used by Etkin and colleagues employs pairs of stimuli that combine fearful or happy faces with the words " FEAR " or " HAPPY. " In this study, " conflict " entails the presence of competing stimuli (e.g., " HAPPY " printed on a fearful face) in incongruent trials, and " absence of conflict " refers to synergistic stimuli (e.g., " HAPPY " on happy faces) in congruent trials. Subjects were instructed to identify the facial emotion (target stimulus) as fast as possible, while ignoring the word (distracter stimulus). Consistent with the conflict monitoring theory described above, the incongruent stimuli engage the conflict detection node. This node, in turn, activates the conflict resolution system, which biases information processing and promotes correct responding. It is at this critical point that the focus of this …