Fig. 2.

Event-related potentials (ERPs) from experiments 1–3. Response-aligned grand average correct no-stop (thin solid line) and errant noncanceled waveforms (thick broken line) at each midline scalp site (Fz, Cz, and Pz) are shown for saccadic (A), unimanual/simple RT (B), and bimanual/2-alternative forced choice (2AFC) RT (C) experiments. Shaded regions represent significant differences in the error-related negativity (ERN; light gray) and error positivity (Pe; dark gray) components. Response-aligned grand average bipolar horizontal (HEOG) and vertical electrooculogram (VEOG) waveforms for right (blue) and left (red) peripheral target locations and errant noncanceled and correct no-stop trials are illustrated for each experiment. Note that in this and all subsequent figures, negativity is plotted upwardly.