title: Auditory mismatch negativity and repetition suppression deficits in schizophrenia explained by irregular computation of prediction error.
abstract: BACKGROUND
  The predictive coding model is rapidly gaining attention in schizophrenia research. It posits the neuronal computation of residual variance ('prediction error') between sensory information and top-down expectation through multiple hierarchical levels. Event-related potentials (ERP) reflect cortical processing stages that are increasingly interpreted in the light of the predictive coding hypothesis. Both mismatch negativity (MMN) and repetition suppression (RS) measures are considered a prediction error correlates based on error detection and error minimization, respectively.
  
  
  METHODS
  Twenty-five schizophrenia patients and 25 healthy controls completed auditory tasks designed to elicit MMN and RS responses that were investigated using repeated measures models and strong spatio-temporal a priori hypothesis based on previous research. Separate correlations were performed for controls and schizophrenia patients, using age and clinical variables as covariates.
  
  
  RESULTS
  MMN and RS deficits were largely replicated in our sample of schizophrenia patients. Moreover, MMN and RS measures were strongly correlated in healthy controls, while no correlation was found in schizophrenia patients. Single-trial analyses indicated significantly lower signal-to-noise ratio during prediction error computation in schizophrenia.
  
  
  CONCLUSIONS
  This study provides evidence that auditory ERP components relevant for schizophrenia research can be reconciled in the light of the predictive coding framework. The lack of any correlation between the investigated measures in schizophrenia patients suggests a disruption of predictive coding mechanisms in general. More specifically, these results suggest that schizophrenia is associated with an irregular computation of residual variance between sensory input and top-down models, i.e. prediction error.
authors.affiliation: Department of Psychiatry, Charité University Medicine, Berlin, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Rentzsch
authors.affiliation: Department of Psychiatry, Charité University Medicine, Berlin, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Shen
authors.affiliation: Department of Psychiatry, Charité University Medicine, Berlin, Germany; Department of Psychiatry, Oberhavel Hospital, Hennigsdorf, Germany.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Jockers-Scherübl
authors.affiliation: Department of Psychiatry, Charité University Medicine, Berlin, Germany; Department of Psychiatry, University Hospital Eppendorf, Hamburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
authors.affiliation: Department of Psychiatry, Charité University Medicine, Berlin, Germany.
authors.forename: Andres H
authors.initials: AH
authors.lastname: Neuhaus
mesh_terms: D000293:Adolescent; D000328:Adult; D003198:Computer Simulation; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D055815:Young Adult