Fig. 2

Upper plot shows a typical EEG trial in which target ERPs, namely N100 and P200, are present. Bottom plot simulates ERPs denoising after synchronous and asynchronous average of 100 trials. The smooth, black, and thick line shows the two target ERPs. The thin and dotted lines are the results of synchronous and asynchronous averaging, respectively. In the asynchronous average, the onset error was uniformly distributed in the range [0–60 ms]. Longer latencies and lower amplitudes in comparison with the synchronous denoising can be observed for N100 and P200