Action-Outcome Knowledge Dissociates From Behavior in Obsessive-Compulsive Disorder Following Contingency Degradation.

Abstract

Background. In obsessive–compulsive disorder (OCD), actions persist despite being inappropriate to the situation and without relationship to the overall goal. Dysfunctional beliefs have traditionally been postulated to underlie this condition. More recently, OCD has been characterised in terms of an imbalance between the goal-directed and the habit system. To test these competing hypotheses, we used a novel experimental task designed to test subjective action-outcome knowledge of the effectiveness of actions (i.e., instrumental contingency), together with the balance between goal-directed and habitual responding.

Methods. Twenty-seven patients with OCD and 27 healthy subjects were tested on a novel task involving the degradation of an action–outcome contingency. Sensitivity to instrumental contingency and the extent to which explicitly reported action-outcome knowledge guided behavior, was probed by measuring response rate and subjectively reported judgments.

Results. Patients with OCD responded more than controls in situations in which an action was less causally related to obtaining an outcome. However, patients showed intact explicit action–outcome knowledge, as assessed by self-report. In patients the relationship between causality judgment and responding was altered, therefore their actions were dissociated from explicit action-outcome knowledge.

Conclusions. These findings indicate reduced sensitivity to instrumental contingency in OCD, reinforcing the notion of a deficient goal-directed system in this disorder. By showing a dissociation between subjectively reported action–outcome knowledge and behavior, the data provide experimental evidence for the ego-dystonic nature of OCD.