title: Shifted neuronal balance during stimulus-response integration in schizophrenia: an fMRI study.
abstract: Schizophrenia is characterized by marked deficits in executive and psychomotor functions, as demonstrated for goal-directed actions in the antisaccade task. Recent studies, however, suggest that this deficit represents only one manifestation of a general deficit in stimulus-response integration and volitional initiation of motor responses. We here used functional magnetic resonance imaging to investigate brain activation patterns during a manual stimulus-response compatibility task in 18 schizophrenic patients and 18 controls. We found that across groups incongruent vs. congruent responses recruited a bilateral network consisting of dorsal fronto-parietal circuits as well as bilateral anterior insula, dorsolateral prefrontal cortex (DLPFC) and the presupplementary motor area (preSMA). When testing for the main-effect across all conditions, patients showed significantly lower activation of the right DLPFC and, in turn, increased activation in a left hemispheric network including parietal and premotor areas as well as the preSMA. For incongruent responses patients showed significantly increased activation in a similar left hemispheric network, as well as additional activation in parietal and premotor regions in the right hemisphere. The present study reveals that hypoactivity in the right DLPFC in schizophrenic patients is accompanied by hyperactivity in several fronto-parietal regions associated with task execution. Impaired top-down control due to a dysfunctional DLPFC might thus be partly compensated by an up-regulation of task-relevant regions in schizophrenic patients.
authors.affiliation: Institute of Clinical Neuroscience and Medical Psychology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany, e.cieslik@fz-juelich.de.
authors.forename: Edna C
authors.initials: EC
authors.lastname: Cieslik
authors.forename: Veronika I
authors.initials: VI
authors.lastname: Müller
authors.forename: Tanja S
authors.initials: TS
authors.lastname: Kellermann
authors.forename: Christian
authors.initials: C
authors.lastname: Grefkes
authors.forename: Sarah
authors.initials: S
authors.lastname: Halfter
authors.forename: Simon B
authors.initials: SB
authors.lastname: Eickhoff
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000473:pathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance; D012559:Schizophrenia / Q000473:pathology*; D018709:Statistics, Nonparametric; D014796:Visual Perception
chemical_list: D010100:Oxygen