Error-related hyperactivity of the anterior cingulate cortex in obsessive-compulsive disorder.

BACKGROUND: Hyperactivity of the anterior cingulate cortex (ACC) in patients with obsessive-compulsive disorder (OCD) has been shown to increase with symptom provocation and to normalize with treatment-induced symptom reduction. Although the functional significance of anterior cingulate involvement in OCD remains unknown, electrophysiological evidence has linked this region to error-processing abnormalities in patients with OCD. In this functional magnetic resonance imaging (fMRI) study, we sought to further localize error-processing differences within the ACC of OCD patients compared with healthy subjects. METHODS: Event-related fMRI data were collected for eight OCD patients and seven healthy subjects during the performance of a simple cognitive task designed to elicit errors but not OCD symptoms. RESULTS: Both OCD patients and healthy subjects demonstrated dorsal ACC activation during error commission. The OCD patients exhibited significantly greater error-related activation of the rostral ACC than comparison subjects. Activity in this region was positively correlated with symptom severity in the patients. CONCLUSIONS: Error-processing abnormalities within the rostral anterior cingulate occur in the absence of symptom expression in patients with OCD.