Response-locked ERP waveforms were averaged from 1-s sub-epochs including 700 ms before and 300 ms after the recorded response and applying the stimulus-locked baseline correction. Although trials with responses faster than 400 ms or slower than 1,400 ms had to be excluded when computing response-locked ERPs, because of insufficient sample points at the beginning or end of the sub-epochs, the number of remaining trials was still sufficient in each group (92.3% for controls and 85.7% for patients of stimulus-locked trials).
