title: Theta response in schizophrenia is indifferent to perceptual illusion.
abstract: OBJECTIVE
  Patients with schizophrenia are impaired in maintaining coherent perceptual experiences. This is reflected in the oscillatory theta response and can be investigated by visual illusions. Ambiguous stimuli elicit illusory perceptual switches while the stimulus remains unchanged.
  
  
  METHODS
  Theta responses elicited by an ambiguous and unambiguous control stimulus were measured using the EEG during time periods of perceptual switching and perceptual stability (non-switching).
  
  
  RESULTS
  For the ambiguous task, theta activity increased during perceptual switching in healthy controls only. For the unambiguous task, the switching-related increase of theta activity was larger in controls than in patients. This reduced modulation of the theta response seems not to be related to a general decrease of theta activity in patients.
  
  
  CONCLUSIONS
  These findings may be related to disturbances in the spatio-temporal integration of neural activity in patients. Reporting ambiguous and unambiguous perceptual switches seems to be more demanding for patients with schizophrenia than healthy controls.
  
  
  CONCLUSIONS
  This is one of the first studies on the neurophysiologic correlates of illusory perception in schizophrenia. Focussing on the relation between different brain states (such as switching and non-switching) might integrate different findings about altered theta oscillations in schizophrenia.
authors.affiliation: University of Bremen, Institute of Psychology and Cognition Research, Bremen, Germany; Centre for Cognitive Science, Bremen, Germany. Electronic address: birgit.mathes@uni-bremen.de.
authors.forename: Birgit
authors.initials: B
authors.lastname: Mathes
authors.affiliation: University of Bremen, Institute of Psychology and Cognition Research, Bremen, Germany; Centre for Cognitive Science, Bremen, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Schmiedt-Fehr
authors.affiliation: University of Bremen, Institute of Psychology and Cognition Research, Bremen, Germany; Centre for Cognitive Science, Bremen, Germany.
authors.forename: Shwetha
authors.initials: S
authors.lastname: Kedilaya
authors.affiliation: Experimental Psychology Lab, Dpt. of Psychology, European Medical School, University of Oldenburg, Germany; Research Center Neurosensory Science, University of Oldenburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Strüber
authors.affiliation: University of Bremen, Institute of Psychology and Cognition Research, Bremen, Germany; Centre for Cognitive Science, Bremen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Brand
authors.affiliation: University of Bremen, Institute of Psychology and Cognition Research, Bremen, Germany; Centre for Cognitive Science, Bremen, Germany.
authors.forename: Canan
authors.initials: C
authors.lastname: Basar-Eroglu
mesh_terms: D000328:Adult; D004569:Electroencephalography / Q000379:methods / Q000523:psychology; D005260:Female; D006801:Humans; D007088:Illusions / Q000502:physiology* / Q000523:psychology*; D008297:Male; D009039:Motion Perception / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D013826:Theta Rhythm / Q000502:physiology*; D055815:Young Adult
keywords: Brain oscillations; Long-range coordination; Multistable perception; Object perception; Top-down bottom-up