title: Pre-attentive auditory processing in ultra-high-risk for schizophrenia with magnetoencephalography.
abstract: BACKGROUND
  It is uncertain whether the neurobiological abnormalities in schizophrenia emerge at the first episode of the disorder or are present during the prodromal phase. Recent neuroimaging studies indicate that some brain abnormalities are present in subjects at ultra-high-risk (UHR) for schizophrenia. Pre-attentive auditory deficits, which represent a core feature of schizophrenia, were investigated in individuals at UHR for schizophrenia.
  
  
  METHODS
  We assessed early auditory processing indexed by the magnetoencephalographic mismatch negativity magnetic counterpart (MMNm) component elicited during a passive oddball paradigm in UHR individuals. Sixteen individuals at UHR for schizophrenia on the basis of clinical criteria and 18 healthy control subjects matched for age, gender, and education participated. A duration-deviant oddball paradigm was used to obtain MMNm dipole moment, which was measured with cortical source modeling.
  
  
  RESULTS
  The UHR group showed a smaller right MMNm dipole moment than those of the control group. Group difference was observed in MMNm dipole latency, suggestive of slowed processing. The left MMNm dipole moment was negatively correlated with clinical symptoms measured by the Comprehensive Assessment of At-Risk Mental States positive symptom score.
  
  
  CONCLUSIONS
  Our findings suggest that deficits in the early stage of auditory processing in individuals at UHR for schizophrenia exist before the onset of psychosis. The MMNm dipole moment might reflect the functional decline at the prodromal stage of schizophrenia.
authors.affiliation: Interdisciplinary Program in Cognitive Science, Seoul National University, Seoul, Korea.
authors.forename: Kyung Soon
authors.initials: KS
authors.lastname: Shin
authors.forename: June Sic
authors.initials: JS
authors.lastname: Kim
authors.forename: Do-Hyung
authors.initials: DH
authors.lastname: Kang
authors.forename: Yuri
authors.initials: Y
authors.lastname: Koh
authors.forename: Jung-Seok
authors.initials: JS
authors.lastname: Choi
authors.forename: Brian F
authors.initials: BF
authors.lastname: O'Donnell
authors.forename: Chun Kee
authors.initials: CK
authors.lastname: Chung
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
mesh_terms: D000161:Acoustic Stimulation; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001288:Attention / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D011569:Psychiatric Status Rating Scales; D012306:Risk; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology; D012565:Schizophrenic Psychology; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents