Distractor value reduces the amplitude of the late positive-going deflection (LPD or P300). A: stimulus-locked centroparietal ERPs across differential choice values (low to high from left to right) and distractor values (low, medium, and high). B: mean amplitude of the LPD component, plotted as a function of differential choice value and distractor value. LPD amplitude decreases as distractor value increases (see topography in C). In contrast, LPD amplitude increases as differential choice value increases (see topography in D). Error bars represent within-subject SE. ††,***Significant main effect of differential choice value (P < 0.01) and distractor value (P < 0.001), respectively.