title: Evaluative processing of ambivalent stimuli in patients with schizophrenia and depression: a [15O] H2O PET study.
abstract: Decision making in an emotionally conflicting situation is important in social life. We aimed to address the similarity and disparity of neural correlates involved in processing ambivalent stimuli in patients with schizophrenia and patients with depression. Behavioral task-related hemodynamic responses were measured using [15O]H2O positron emission tomography (PET) in 12 patients with schizophrenia and 12 patients with depression. The task was a modified word-stem completion task, which was designed to evoke ambivalence in forced and non-forced choice conditions. The prefrontal cortex and the cerebellum were found to show increased activity in the healthy control group. In the schizophrenia group, activity in these two regions was negligible. In the depression group, the pattern of activity was altered and a functional compensatory recruitment of the inferior parietal regions was suggested. The prefrontal cortex seems to be associated with the cognitive control to resolve the conflict toward the ambivalent stimuli, whereas the cerebellum reflects the sustained working memory to search for compromise alternatives. The deficit of cerebellar activation in the schizophrenia group might underlie the inability to search and consider compromising responses for conflict resolution.
authors.affiliation: Institute of Behavioral Science in Medicine, Yonsei University College of Medicine, Gwangju Gyeonggi, Korea.
authors.forename: Jae-Jin
authors.initials: JJ
authors.lastname: Kim
authors.forename: Hae-Jeong
authors.initials: HJ
authors.lastname: Park
authors.forename: Young-Chul
authors.initials: YC
authors.lastname: Jung
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Chun
authors.forename: Hye Sun
authors.initials: HS
authors.lastname: Kim
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Seok
authors.forename: Nam Wook
authors.initials: NW
authors.lastname: Kim
authors.forename: Il Ho
authors.initials: IH
authors.lastname: Park
authors.forename: Maeng-Gun
authors.initials: MG
authors.lastname: Oh
authors.forename: Jong Doo
authors.initials: JD
authors.lastname: Lee
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D001931:Brain Mapping; D002755:Choice Behavior / Q000502:physiology; D032882:Comprehension / Q000502:physiology; D003657:Decision Making / Q000502:physiology*; D003863:Depression / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010103:Oxygen Isotopes; D049268:Positron-Emission Tomography / Q000379:methods; D012559:Schizophrenia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D013223:Statistics as Topic; D014867:Water; D055815:Young Adult
chemical_list: D010103:Oxygen Isotopes; D014867:Water