Fig. 2.

Grand-average ERP waveforms elicited by the final chords, (A) in the subgroup in which irregular chord functions were supertonics and (B) in the subgroup in which irregular chord functions were Neapolitan sixth chords. The solid grey lines indicates potentials elicited by regular (tonic) chords, the dotted grey line responses to irregular chords (supertonic or Neapolitan sixth chord). The thick black lines represent the difference wave (regular subtracted from irregular chords) – dashed in the subgroup where supertonics served as irregular chords, solid in the subgroup where Neapolitan sixth chords served as irregular chords. The ERAN is indicated by an arrow.