title: Auditory and visual P300 topography from a 3 stimulus paradigm.
abstract: OBJECTIVE
  The P300 event-related brain potential (ERP) was elicited with auditory and visual stimuli in a separate session of a 3 stimulus oddball paradigm, and the scalp topography was assessed with 15 electrode locations.
  
  
  METHODS
  Target (0.10), standard (0.80), and infrequent non-target (0.10) stimuli in the auditory task were 2000, 1000 and 500 Hz tone, and in the visual task, 'X', 'O', and 'H', respectively. The stimuli were presented in a random series, once every 2 s, and participants responded only to the target (N = 12).
  
  
  RESULTS
  Target stimuli elicited larger P300 components than non-target did in both stimulus modalities. For both target and non-target stimuli, P300 amplitude was larger and latency longer for the visual compared with the auditory stimulus. Analysis of normalized P300 amplitude data indicated that the target and non-target P300s from both modalities had identical topography.
  
  
  CONCLUSIONS
  The findings suggest that both target and non-target stimuli in 3 stimulus oddball paradigm elicited the same type of P300 (P3b) for both stimulus modalities.
authors.affiliation: Faculty of Education, Hokkaido University, Sapporo, Japan. jk@edu.hokudai.ac.jp
authors.forename: J
authors.initials: J
authors.lastname: Katayama
authors.forename: J
authors.initials: J
authors.lastname: Polich
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology