Jaafari, N. 1 , Descoust, M. 2 , Frasca, M. 2 , Rigalleau, F. 2 & Vibert, N. 2
1 Unité de Recherche Clinique en Psychiatrie, Centre Hospitalier Henri Laborit et Université de Poitiers, Poitiers, France
2 CeRCA, CNRS - Université de Poitiers, Poitiers, France
Obsessive-compulsive disorder (OCD) is a psychiatric disease associated with abnormalities of the orbitofrontal prefrontal cortex. This study was aimed at clarifying the relationships between working memory capacities, executive abilities and neurological soft signs (NSS), i.e. three measures that have been linked to prefrontal brain areas, in OCD patients. Participants were 43 patients and their individually-matched controls. The verbal and visuo-spatial components of participants’ working memory were evaluated using the reading span and the backward location span tests. Executive functions were assessed through selective attention tests involving active inhibition (the Stroop and d2 target crossing tests), tests assessing information retrieval from long-term memory (the verbal fluency and Hayling sentence completion tests), and a task switching test. OCD patients’ working memory spans were both reduced compared to controls. All OCD patients’ executive abilities were impaired, but their performance was particularly low on all tests involving active inhibition processes. NSS were more frequent in OCD patients than in controls, and there was a negative correlation between the OCD patients’ intensity of NSS, their working memory spans and their performance on the Stroop and d2 selective inhibition tests. This suggests that NSS might be used as an index of the prefrontal abnormalities underlying OCD.