Fig. 2.

Topographic maps for each of the four time windows of the LPP, depicting differences (in µV) in the sample as a whole for pleasant minus neutral and unpleasant minus neutral pictures; activity in each time window is depicted from two angles to display parietal (left) and frontal (right) effects. Also depicted are stimulus-locked ERP waveforms reflecting the average activity at Fz (top) and Pz (bottom), referenced to an average of the mastoids. Stimulus onset is at time 0 and negative is plotted up.