Inhibition of return in obsessive-compulsive disorder.

Obsessive-compulsive disorder (OCD) is characterized by repetitive obsessions and/or compulsions that interfere with daily functioning. Neuropsychological studies have suggested that such perseverative behaviors may be due to underlying attentional deficits. Inhibition of return (IOR) is an adaptive mechanism that is thought to assist visual search by biasing attention after a critical, short interval to novel, previously unattended areas. Therefore, this study aimed to examine whether deficient IOR mechanisms could underlie some of the attentional, and perhaps behavioral, problems, reported in OCD patients. Using a computerized IOR paradigm, participants were required to respond to a target that appeared at either the same or different location to a precue that was presented either 100 ms or 700 ms earlier. Results indicate that patients had a reduced IOR for targets presented in the left visual field, suggesting lateralized anomalies in shifting attention. Results are consistent with lateralization anomalies previously reported in OCD.