Figure 2. Event-related potential waveforms for midline electrodes and sensor layout.

a) Grand average waveforms depicting ERP activity at Fz (top), Cz (middle), and Pz (bottom). b) Sensor layout of the 128-channel geodesic sensor net. Solid-line circle indicates centro-parietal recording sites averaged for the early and late P3-like components. cC = congruent trial preceded by a congruent trial, cI = incongruent trial preceded by a congruent trial, iC = congruent trial preceded by an incongruent trial, iI = incongruent trial preceded by an incongruent trial.