title: Arithmetic mismatch negativity and numerical magnitude processing in number matching.
abstract: BACKGROUND
  This study examined the relationship of the arithmetic mismatch negativity (AMN) and the semantic evaluation of numerical magnitude. The first question was whether the AMN was sensitive to the incongruity in numerical information per se, or rather, to the violation of strategic expectations. The second question was whether the numerical distance effect could appear independently of the AMN. Event-related potentials (ERPs) were recorded while participants decided whether two digits were matching or non-matching in terms of physical similarity.
  
  
  RESULTS
  The AMN was enhanced in matching trials presented infrequently relative to non-matching trials presented frequently. The numerical distance effect was found over posterior sites during a 92 ms long interval (236-328 ms) but appeared independently of the AMN.
  
  
  CONCLUSIONS
  It was not the incongruity in numerical information per se, but rather, the violation of strategic expectations that elicited the AMN. The numerical distance effect might only temporally coincide with the AMN and did not form an inherent part of it.
authors.affiliation: Centre for Neuroscience in Education, Department of Experimental Psychology, University of Cambridge, Downing site, Cambridge CB2 3EB, UK.
authors.forename: Yi-Fang
authors.initials: YF
authors.lastname: Hsu
authors.forename: Dénes
authors.initials: D
authors.lastname: Szücs
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012659:Semantic Differential; D013647:Task Performance and Analysis