title: Impairment of source memory in patients with obsessive-compulsive disorder: equivalent current dipole analysis.
abstract: We examined memory performance and cortical source localization of old/new effects in a source memory task in obsessive-compulsive disorder (OCD) patients by employing an equivalent current dipole (ECD) model using EEG and a realistic head model. Event-related potentials (ERPs) were recorded while 14 OCD patients and 14 age-, sex-, handedness-, and educational level-matched healthy control subjects performed recognition tasks for spoken words (items) or for the voice of the speaker of spoken words (sources). In the item memory task, both groups showed ERP old/new effects at 300-700 ms. In the source memory task, the controls showed ERP old/new effects at 400-700 ms, whereas the OCD patients did not. Compared with the controls, the OCD patients showed significantly lower source accuracy and prolonged reaction times to the old words with accurate voice judgments. There were no differences between the OCD and control groups with regard to the locations of the ERP generators elicited by source correct and correct rejection conditions. The OCD patients showed significantly altered hemispheric asymmetry of ECD power in the frontal lobe during source memory retrieval, compared with the controls. These results indicate that OCD patients have preserved item memory about content, but impaired source memory about context.
authors.affiliation: BK21 Research Division of Human Life Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Youn
authors.initials: YY
authors.lastname: Kim
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Roh
authors.forename: So Young
authors.initials: SY
authors.lastname: Yoo
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Kang
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007600:Judgment / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009771:Obsessive-Compulsive Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D019047:Phantoms, Imaging; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology; D012016:Reference Values; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception / Q000502:physiology; D014706:Verbal Learning / Q000502:physiology*; D014833:Voice Quality / Q000502:physiology; D055815:Young Adult