A one-sample t-test of the difference wave of deviants (tones in the 1st position) minus final tones in the 4th to 30th positions confirmed that the average peak amplitude was significantly smaller than zero (M= -0.91 μV, SD = 0.47 μV; t (34) = -11.59, p< .001), showing that the MMN was elicited. The MMN waveform and topography with fronto-central negativity and temporal positivity are shown in Figure 3.