Hemispheric functional imbalance in a sub-clinical obsessive-compulsive sample assessed by the Continuous Performance Test, Identical Pairs version

Obsessive-compulsive disorder (OCD) sufferers have long been observed to give excessive consideration to normally ignored exogenous and endogenous stimuli. This over-focused attention concerning their symptoms has led researchers to experimentally investigate the attentional mechanisms involved in this disorder and its psychobiological basis. Previous psychometric and neuropsychological research has demonstrated the validity of the sub-clinical analogue in the study of the mechanisms underlying OCD. In this study, 71 introductory university students were recruited from an original pool of 450 people on the basis of their scores on the Spanish version of the Padua Inventory. A high obsessive group (n = 35) was compared with a control group (n = 36) on a standard sustained attention task: the Continuous Performance Test, Identical Pairs version (CPT-IP). The results showed a significant interaction effect between CPT-IP subscales (verbal and spatial) and group membership. This effect was more evident among men. The results were unrelated to general intelligence, depression, anxiety, personality or motivational factors. These findings support the hypothesis that neuropsychological deficits in OCD may be related to a hemispheric functional imbalance rather than to a lateralised dysfunction of a particular hemisphere. (C) 1997 Elsevier Science Ireland Ltd.