Habitual or hyper-controlled behavior: OCD symptoms and explicit sequence learning

This study examined whether ritualistic behaviors characteristic of obsessive-compulsive disorder (OCD) are a product of dysfunctional goal-directed behavior leading to habitual behavior (Gillan & Robbins, 2014). We used an explicit motor sequence learning task to investigate the repetition of chunked action sequences across the OC spectrum. As sequential motor behavior is practiced, action movements appear to get bundled together, and the initial movement of the sequence activates the entire sequence, leaving it relatively insensitive to change. Therefore, compulsive behavior in OCD may be a result of failing to inhibit the full activation of an extensively learned action sequence.

Fifty-seven participants across the range of OCD symptoms practiced one sequence and then tested on a novel sequence in which one of the middle movements was omitted. Optimal performance for the new sequence required goal-directed inhibition of the original sequence and goal-directed execution of the new sequence instead. To manipulate activation of goal-directed behavior, we added a dual-task condition with a competing auditory tonal N-Back task. Data were analyzed using mixed-effects models.

Although we did observe expected learning patterns during learning of the original sequence, slower reaction times for the new sequences, and higher errors in the dual-task condition, performance was not significantly related to either obsessive-compulsive symptoms or distress symptoms.

The current study used an analog sample; replication in a treatment seeking sample is warranted.

These findings challenge the goal-directed dysfunction model of OCD.