CAN PATIENTS WITH OBSESSIVE-COMPULSIVE DISORDER DISCRIMINATE BETWEEN PERCEPTS AND MENTAL IMAGES - A SIGNAL-DETECTION ANALYSIS

Signal detection analysis was used to test three hypotheses for repeti tive thoughts and behaviors characteristic of obsessive-compulsive dis order (OCD). Patients might have (a) low sensitivity for the differenc e between having seen something or having imagined seeing it, (b) a hi gh criterion for this discrimination, or (c) difficulty associating co ntext with information in memory. Subjects judged viewed words or imag ined words and later indicated which were actually seen. Patients with OCD discriminated seen from imaged words significantly better than no rmal control subjects, as evidenced by higher d' scores on a recogniti on memory task. Groups did not differ in response criterion, beta, use d to decide whether words had been seen or imaged. Implications for th e study of OCD from an information-processing perspective are discusse d.