Grand average ERPs time-locked to the audio onset for the three electrodes (Cz, Pz, and O1) in the AO (blue) and AV (red) conditions.
The black vertical line indicates the audio onset. The left panels are for ESs (N = 8) and right panels for JSs (N = 12). The coloured topographic map shows the differences in amplitude between the two conditions (AV−AO) for the 170–220 ms time window (depicted by the grey background on each graph). The colour distribution of the two maps clearly demonstrates the differences between ESs and JSs for the central and posterior electrodes (see Table 2 for statistics). ERP: event-related potential.