title: LORETA current source density for duration mismatch negativity and neuropsychological assessment in early schizophrenia.
abstract: BACKGROUND
  Patients with schizophrenia elicit cognitive decline from the early phase of the illness. Mismatch negativity (MMN) has been shown to be associated with cognitive function. We investigated the current source density of duration mismatch negativity (dMMN), by using low-resolution brain electromagnetic tomography (LORETA), and neuropsychological performance in subjects with early schizophrenia.
  
  
  METHODS
  Data were obtained from 20 patients meeting DSM-IV criteria for schizophrenia or schizophreniform disorder, and 20 healthy control (HC) subjects. An auditory odd-ball paradigm was used to measure dMMN. Neuropsychological performance was evaluated by the brief assessment of cognition in schizophrenia Japanese version (BACS-J).
  
  
  RESULTS
  Patients showed smaller dMMN amplitudes than those in the HC subjects. LORETA current density for dMMN was significantly lower in patients compared to HC subjects, especially in the temporal lobes. dMMN current density in the frontal lobe was positively correlated with working memory performance in patients.
  
  
  CONCLUSIONS
  This is the first study to identify brain regions showing smaller dMMN current density in early schizophrenia. Further, poor working memory was associated with decreased dMMN current density in patients. These results are likely to help understand the neural basis for cognitive impairment of schizophrenia.
authors.affiliation: Department of Neuropsychiatry, University of Toyama Graduate School of Medicine and Pharmaceutical Sciences, Toyama, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Miyanishi
authors.forename: Tomiki
authors.initials: T
authors.lastname: Sumiyoshi
authors.forename: Yuko
authors.initials: Y
authors.lastname: Higuchi
authors.forename: Tomonori
authors.initials: T
authors.lastname: Seo
authors.forename: Michio
authors.initials: M
authors.lastname: Suzuki
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D016022:Case-Control Studies; D018450:Disease Progression; D004553:Electric Conductivity; D055590:Electromagnetic Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D009483:Neuropsychological Tests; D011618:Psychotic Disorders / Q000150:complications; D012559:Schizophrenia / Q000150:complications / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D013702:Temporal Lobe / Q000473:pathology / Q000503:physiopathology; D014054:Tomography; D055815:Young Adult