title: Altered contextual modulation of primary visual cortex responses in schizophrenia.
abstract: Schizophrenia is typically associated with higher-level cognitive symptoms, such as disorganized thoughts, delusions, and hallucinations. However, deficits in visual processing have been consistently reported with the illness. Here, we provide strong neurophysiological evidence for a marked perturbation at the earliest level of cortical visual processing in patients with paranoid schizophrenia. Using functional magnetic resonance imaging (fMRI) and adapting a well-established approach from electrophysiology, we found that orientation-specific contextual modulation of cortical responses in human primary visual cortex (V1)--a hallmark of early neural encoding of visual stimuli--is dramatically reduced in patients with schizophrenia. This indicates that contextual processing in schizophrenia is altered at the earliest stages of visual cortical processing and supports current theories that emphasize the role of abnormalities in perceptual synthesis (eg, false inference) in schizophrenia.
authors.affiliation: 1] Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité Universitätsmedizin Berlin, Berlin, Germany [2] Department of Cognitive Science, Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, NSW, Australia.
authors.forename: Kiley
authors.initials: K
authors.lastname: Seymour
authors.forename: Timo
authors.initials: T
authors.lastname: Stein
authors.forename: Lia Lira Olivier
authors.initials: LL
authors.lastname: Sanders
authors.forename: Matthias
authors.initials: M
authors.lastname: Guggenmos
authors.forename: Ines
authors.initials: I
authors.lastname: Theophil
authors.forename: Philipp
authors.initials: P
authors.lastname: Sterzer
mesh_terms: D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009949:Orientation / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010468:Perceptual Disorders / Q000209:etiology*; D010775:Photic Stimulation; D012559:Schizophrenia / Q000150:complications* / Q000473:pathology*; D014793:Visual Cortex / Q000098:blood supply / Q000503:physiopathology*
chemical_list: D010100:Oxygen