Fig. 3

Statistical cluster plots of the MMN: comparing the amplitude of the AEP in response to the standard versus oddball stimulus, for each group. Significant differences are seen in the control group (left) over central and fronto-central areas (see also Figs. 1 and 2) at 50–70 ms and 100–120 ms. For the Rett group (right), the first wave of significant differences is seen at 130–180 ms, and a second at about 300 ms. Significant T values indicate a t-stat value of ≥2 for at least 20 consecutive milliseconds and three nearby electrode sites