title: Altered center-surround motion inhibition in schizophrenia.
abstract: BACKGROUND
  Schizophrenia is a brain disorder that spans across biological and behavioral levels. The links between altered neural circuitry and abnormal behaviors are yet to be understood. Visual motion perception has been established in basic neuroscience and may provide an opportunity to link different levels of brain functions in schizophrenia. Center-surround interaction is a ubiquitous neural mechanism underlying the organization of visual information over different spatial locations.
  
  
  METHODS
  We applied a psychophysical paradigm to examine center-surround interaction in schizophrenia. Patients (n = 24) and control subjects (n = 33) judged the direction of a moving random dot pattern (RDP, center) with and without the presence of another concentric surrounding RDP (surround).
  
  
  RESULTS
  The presence of a moving surround shifted the perceptual judgments of center motion in the opposite direction from the surround in both subject groups but the magnitude of the perceptual shift was significantly larger in patients. The increased perceptual shift was not correlated with psychotic symptoms, which were mild in this patient sample, or antipsychotic medication.
  
  
  CONCLUSIONS
  The increased perceptual shift suggests that the putative surround suppression on visual motion perception is abnormally increased in schizophrenia. This result provides perceptual evidence for altered basic inhibitory control of visual motion context in schizophrenia.
authors.affiliation: McLean Hospital, Department of Psychiatry, Harvard Medical School, Belmont, Massachusetts, USA. ychen@mclean.harvard.edu
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.forename: Daniel
authors.initials: D
authors.lastname: Norton
authors.forename: Dost
authors.initials: D
authors.lastname: Ongur
mesh_terms: D000328:Adult; D001288:Attention; D004193:Discrimination Learning; D005260:Female; D005364:Field Dependence-Independence; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D009039:Motion Perception; D009949:Orientation; D010364:Pattern Recognition, Visual; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology