ALTERNATION LEARNING IN OBSESSIVE-COMPULSIVE DISORDER

The Wisconsin Card Sorting Test (WCST) and an alternation learning tas k were administered to 15 women with obsessive-compulsive disorder (OC D) and 15 age-, sex-, education-, and intelligence-matched healthy con trols. OCD patients were significantly slower on the WCST as compared to the controls. Their performance on the alternation learning task wa s impaired relative to the control group, though this difference was d iminished when we used education as a covariate, We found a significan t positive correlation between performance on the alternation task and severity of symptoms in the OCD group, performance of similar alterna tion tasks is impaired by damage to the orbitofrontal cortex in nonhum an primates, Therefore the data presented support the hypothesis of or bitofrontal cortex dysfunction in OCD.