Abnormalities of internally generated saccades in obsessive-compulsive disorder

Background. We aimed to utilize tests of saccadic function to investigate w hether cognitive abnormalities in obsessive-compulsive disorder (OCD) arise from a dysfunction of inhibitory processes or whether they reflect a more general difficulty in guiding behaviour on the basis of an internal represe ntation of task goal. Methods. Twelve patients with OCD and 12 matched controls performed a visua lly-guided saccade task, a volitional prosaccade task and an antisaccade ta sk. The latency and gain of saccades was compared between groups for the th ree saccade tasks. The number of antisaccade errors was also calculated and compared between groups. Results. There was no difference for antisaccade error rates between the gr oups. The latency of visually guided saccades did not differ between groups , however the latency of both volitional prosaccades and antisaccades was s ignificantly slower in the patients with OCD than in controls. The differen ce in latency between volitional prosacades and antisaccades, however, was equal between groups. Conclusions. These results suggest that patients with OCD have an abnormali ty in guiding behaviour on the basis of an internal representation of the t ask goal, rather than a problem with inhibiting reflexive behaviour.