title: Magnetoencephalographic recording of auditory mismatch negativity in response to duration and frequency deviants in a single session in patients with schizophrenia.
abstract: OBJECTIVE
  Auditory mismatch negativity (MMN) and its magnetoencephalographic (MEG) counterpart (MMNm) are an established biological index in schizophrenia research. MMN in response to duration and frequency deviants may have differential relevance to the pathophysiology and clinical stages of schizophrenia. MEG has advantage in that it almost purely detects MMNm arising from the auditory cortex. However, few previous MEG studies on schizophrenia have simultaneously assessed MMNm in response to duration and frequency deviants or examined the effect of chronicity on the group difference.
  
  
  METHODS
  Forty-two patients with chronic schizophrenia and 74 matched control subjects participated in the study. Using a whole-head MEG, MMNm in response to duration and frequency deviants of tones was recorded while participants passively listened to an auditory sequence.
  
  
  RESULTS
  Compared to healthy subjects, patients with schizophrenia exhibited significantly reduced powers of MMNm in response to duration deviant in both hemispheres, whereas MMNm in response to frequency deviant did not differ between the two groups. These results did not change according to the chronicity of the illness.
  
  
  CONCLUSIONS
  These results, obtained by using a sequence-enabling simultaneous assessment of both types of MMNm, suggest that MEG recording of MMN in response to duration deviant may be a more sensitive biological marker of schizophrenia than MMN in response to frequency deviant. Our findings represent an important first step towards establishment of MMN as a biomarker for schizophrenia in real-world clinical psychiatry settings.
authors.affiliation: Department of Rehabilitation, The University of Tokyo, Tokyo, Japan.
authors.forename: Motomu
authors.initials: M
authors.lastname: Suga
authors.affiliation: Department of Neuropsychiatry, The University of Tokyo, Tokyo, Japan.
authors.forename: Yukika
authors.initials: Y
authors.lastname: Nishimura
authors.affiliation: Department of Child Neuropsychiatry, The University of Tokyo, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kawakubo
authors.affiliation: Department of Clinical Laboratory, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Yumoto
authors.affiliation: Department of Neuropsychiatry, The University of Tokyo, Tokyo, Japan.
authors.forename: Kiyoto
authors.initials: K
authors.lastname: Kasai
mesh_terms: D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D015415:Biomarkers; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: duration; frequency; magnetoencephalography; mismatch negativity; schizophrenia