title: Reduced laterality of the source locations for generators of the auditory steady-state field in schizophrenia.
abstract: BACKGROUND
  Reduced hemispheric asymmetry of evoked field generators in schizophrenia in secondary auditory cortex has been replicated with mixed success. This disparity is possibly due to the complex nature of the 100-msec generators typically investigated. In this study, we evaluated a source located in primary auditory cortex, responsible for the steady-state response, to determine whether similar asymmetries were present.
  
  
  METHODS
  Contralateral evoked fields were recorded with a 37-channel neuromagnetometer in response to 40-Hz pulse trains. Dipole models were used to localize the sources in both hemispheres of schizophrenic subjects (n = 17) and normal control subjects (n = 18).
  
  
  RESULTS
  Control subjects were asymmetrically lateralized, with sources in the right hemisphere approximately 6 mm further anterior than those on the left. In contrast, schizophrenic subjects showed no significant difference between hemispheres.
  
  
  CONCLUSIONS
  The findings support theories linking schizophrenia to disturbed asymmetry of temporal lobe function. The steady-state response, having a more discrete Heschl's gyrus generator location, may be better suited for evaluating auditory asymmetry.
authors.affiliation: Biomagnetic Imaging Laboratory, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
authors.forename: Peter
authors.initials: P
authors.lastname: Teale
authors.forename: Jon
authors.initials: J
authors.lastname: Carlson
authors.forename: Donald
authors.initials: D
authors.lastname: Rojas
authors.forename: Martin
authors.initials: M
authors.lastname: Reite
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001921:Brain / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology