Grand average waveforms of the P3 (250–450 ms) and LPP (450–750 ms) ERPs at midline parietal electrodes (CPz, Pz and POz) for (A) control group participants during the unprimed decision stage, (B) control group participants during the primed decision stage, (C) health warning group participants during the unprimed decision stage, and (D) health warning group participants during the primed decision stage. Blue lines denote trials featuring food items perceived as tasty, red lines denote trials featuring food items perceived as not tasty. Positive amplitudes plotted upwards.