title: A common N400 EEG component reflecting contextual integration irrespective of symbolic form.
abstract: OBJECTIVE
  Electroencephalographic (EEG) waves modulated by context have been identified about 400 ms after presentation of a new semantic stimulus, such as a word or a number, within a prior context. However, it is not known if any component of these waves arises from a common brain system activated by different symbolic forms.
  
  
  METHODS
  Multichannel EEG recordings were performed in 10 healthy subjects during the presentation of lexical and numerical series with congruent and incongruent endings. EEG was analysed using a combination of independent component and cluster analysis.
  
  
  RESULTS
  Contextual integration of semantic stimuli elicited a negative independent component at around 400 ms that shared the same pattern of spatio-temporal covariation across numerical series and sentences within single subjects. This independent component was bigger following incongruent endings.
  
  
  CONCLUSIONS
  These data provide evidence that one element of the activity contributing to the N400 is common to different symbolic forms.
  
  
  CONCLUSIONS
  One component of the brain systems evaluating the semantic inter-relationship of new stimuli with prior context may be common to different symbolic forms.
authors.affiliation: Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London WC1N 3BG, UK.
authors.forename: Noa
authors.initials: N
authors.lastname: Fogelson
authors.forename: Constantinos
authors.initials: C
authors.lastname: Loukas
authors.forename: John
authors.initials: J
authors.lastname: Brown
authors.forename: Peter
authors.initials: P
authors.lastname: Brown
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D016000:Cluster Analysis; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D012660:Semantics