Symptom provocation alters behavioral ratings and brain electrical activity in obsessive-compulsive disorder: a preliminary study.

Regional brain activity was measured using quantitative electroencephalography (EEG) in six patients with obsessive-compulsive disorder (OCD) during live and imaginal exposure to feared contaminants. OCD symptoms increased significantly from baseline levels during live and imaginal exposures. However, live exposure provoked significantly more OCD symptoms than imaginal exposure. There was a significant change in the anterior-to-posterior scalp distribution of alpha power during live exposure. These preliminary results suggest that: (1) live exposure is more effective than imaginal exposure in altering behavioral and electrophysiological measures; and (2) live exposure is associated with regional EEG changes in OCD.