title: Auditory evoked potential variability in healthy and schizophrenia subjects.
abstract: OBJECTIVE
  To investigate if the reduced P50, N100 and P200 auditory evoked potential (EP) components and gating deficits seen in schizophrenia can be explained in terms of response incompleteness.
  
  
  METHODS
  Twenty-five healthy and schizophrenia participants were studied using pairs of 1000Hz tones (S1 and S2, 0.5s apart) separated by 8.0s. A correlation-based clustering method identified the responses containing P50, N100, and/or P200 related-activity.
  
  
  RESULTS
  Schizophrenia participants produced fewer S1 and S2 responses containing all three EP components than healthy participants. Healthy participants, but not the patient population, produced fewer and smaller S2 than S1 responses containing all three EP components. However, the S2 responses following complete S1 responses were smaller than the complete S1 responses in both populations.
  
  
  CONCLUSIONS
  The gating deficits observed in schizophrenia are due to two mechanisms. First, the S1 response consistency is less in schizophrenia than in health. Second, the S2 responses are attenuated less in schizophrenia.
  
  
  CONCLUSIONS
  This research contributes to the understanding of response variability and sensory gating in health and schizophrenia. It also extends previous reports that fewer and smaller P300 components are produced in schizophrenia than in health to the mid-latency component range.
authors.affiliation: Department of Electrical and Computer Engineering, and Center for Neuro-Engineering and Cognitive Science, University of Houston, TX 77204-4005, United States. bjansen@uh.edu
authors.forename: Ben H
authors.initials: BH
authors.lastname: Jansen
authors.forename: Lingli
authors.initials: L
authors.lastname: Hu
authors.forename: Nash N
authors.initials: NN
authors.lastname: Boutros
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology*; D016000:Cluster Analysis; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007206:Individuality; D008297:Male; D008875:Middle Aged; D011930:Reaction Time / Q000502:physiology; D012559:Schizophrenia / Q000503:physiopathology*; D055139:Sensory Gating / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted