Forgetting what you have checked: a link between working memory impairment and checking behaviors in obsessive-compulsive disorder.

ABSTRACT

BACKGROUND: Compulsive checking behaviors are common in obsessive-compulsive disorder (OCD). Several authors have suggested that these checking rituals could be related to memory deficits. Our aim was to test whether patients with OCD show working memory impairment in relation to their checking behavior. METHODS: We evaluated the verbal and visuospatial components of patients' and controls' working memory using the reading span and backward location span tests. Checking behaviors were measured by recording participants' eye movements during an image comparison task using a non-invasive, infra-red TOBII 1750 eyetracker. Participants were seated, head-free, in a natural position in front of the eyetracker screen where the images were displayed. RESULTS: Patients with OCD made more gaze moves to compare images than controls. Both patients' working memory spans were reduced, and the patients' deficit in the comparison task was negatively related to their working memory spans. CONCLUSIONS: This work demonstrates that checking behavior in OCD is linked to a general reduction of the patients' verbal and visuospatial working memory span.