title: Neural substrates of visual perceptual learning of simple and complex stimuli.
abstract: OBJECTIVE
  The two experiments described here used event-related potentials (ERPs) to investigate whether perceptual learning of different complexities of stimuli involves different levels of visual cortical processing in human adults.
  
  
  METHODS
  Reaction times and ERPs were recorded during 3 consecutive training sessions in which subjects discriminated between simple stimuli made of line segments or complex stimuli made of compound shapes.
  
  
  RESULTS
  Reaction times in both experiments were shortened across training sessions. For simple stimuli, training resulted in a decreased N1 (125-155ms) and an increased P2 (180-240ms) over the occipital area. For complex stimuli, however, training resulted in a decreased N1 (125-155ms) and N2 (290-340ms) and an increased P3 (350-550ms) over the central/parietal areas.
  
  
  CONCLUSIONS
  These findings suggest that perceptual learning modifies the response at different levels of visual cortical processing related to the complexity of the stimulus.
  
  
  CONCLUSIONS
  The neuronal mechanisms involved in perceptual learning may depend on the nature (e.g. the complexity) of the stimuli used in the discrimination task.
authors.affiliation: Institute of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China. songyan@bmu.edu.cn
authors.forename: Yan
authors.initials: Y
authors.lastname: Song
authors.forename: Yulong
authors.initials: Y
authors.lastname: Ding
authors.forename: Silu
authors.initials: S
authors.lastname: Fan
authors.forename: Zhe
authors.initials: Z
authors.lastname: Qu
authors.forename: Lun
authors.initials: L
authors.lastname: Xu
authors.forename: Chunming
authors.initials: C
authors.lastname: Lu
authors.forename: Danling
authors.initials: D
authors.lastname: Peng
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*