Information processing research has become increasingly important in understanding a large number of different disorders, including obsessive compulsive disorder (OCD). This work, which focuses on the factors affecting attention, encoding (learning), and different types of memory, promises not only to improve our knowledge of the psychopathology of OCD and related problems, but also to influence the treatment of these often severe and debilitating conditions. This chapter reviews the history and research associated with aspects of information processing as they relate to both the psychopathology and treatment of OCD, trichotillomania, and body dysmorphic disorder. This includes descriptions of some experimental methodologies used to assess challenging aspects of cognition in OCD. Consistencies and inconsistencies in the literature are highlighted, and an attempt is made to resolve some of them through conceptualizing information-processing studies as either relevant or irrelevant to the experience of OCD. Ideas and questions for future research are proposed.
