title: Effects of auditory hallucinations on the mismatch negativity (MMN) in schizophrenia as measured by a modified 'optimal' multi-feature paradigm.
abstract: The recently developed Optimal-3 multi-feature MMN paradigm, a shortened version of the 'optimal' multi-feature MMN paradigm, allows for the focused recording of the most widely reported MMN deviants (frequency, duration, intensity) within an efficient and time-saving paradigm. The objective of this study was to examine MMN acoustic change detection in schizophrenia (SZ), and elucidate its association with auditory verbal hallucinations (AH), using the Optimal-3.
  
  
  METHODS
  MMN to duration, frequency and intensity deviants were recorded in 12 SZ outpatients (SZs) with persistent AHs and 12 matched healthy controls (HC). Electrical activity was recorded from 32 scalp electrodes; MMN amplitudes and latencies for each deviant were compared between groups and were correlated with trait (PSYRATS) and state measures of AH severity and Positive and Negative Syndrome Scale (PANSS) ratings in SZs.
  
  
  RESULTS
  SZs showed a significantly smaller duration MMN compared to HCs. Furthermore, in SZs attenuated duration MMN amplitudes were correlated with increased PSYRATS scores, as well as increased PANSS positive symptom, hallucination item and general psychoticism ratings, while attenuated intensity MMN amplitudes were correlated with increased PSYRATS scores.
  
  
  CONCLUSIONS
  This is the first study to examine MMN in SZ within the modified (Optimal-3) multi-feature MMN paradigm. This study corroborates previous research reporting a robust duration MMN deficit in SZ and supports previous findings suggesting that AHs may contribute to MMN deficits in SZ.
authors.affiliation: Department of Psychology/Institute of Neuroscience, Carleton University, Ottawa, Ontario, Canada. Derek.Fisher@rohcg.on.ca
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Fisher
authors.forename: Bryan
authors.initials: B
authors.lastname: Grant
authors.forename: Dylan M
authors.initials: DM
authors.lastname: Smith
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Borracci
authors.forename: Alain
authors.initials: A
authors.lastname: Labelle
authors.forename: Verner J
authors.initials: VJ
authors.lastname: Knott
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D005260:Female; D006212:Hallucinations / Q000523:psychology*; D006309:Hearing; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011930:Reaction Time; D012559:Schizophrenia / Q000503:physiopathology; D012565:Schizophrenic Psychology