The analysis showed significant effects of Current trial type, F(1, 1969) = 91.78, p < .0001, indicating larger amplitudes on incompatible (M = 0.44 µV) compared to compatible trials (M = 1.40 µV), and Previous trial accuracy, F(1, 1969) = 14.57, p < .001, indicating larger amplitudes following correct (M = 0.73 µV) compared to incorrect responses (M = 1.11 µV). These effects were qualified by a Group × Previous trial accuracy × Current trial type interaction, F(2, 1969) = 8.43, p < .001 (see Table 2). On trials following correct responses incompatible arrays elicited larger N2s than compatible arrays for participants in all beverage groups. However, on trials following errors, this pattern was evident in the placebo and control groups only.
