group (Ms = −1.83 & −0.02 µV, respectively), t(1923) = −8.48, p < .001. The effect was less pronounced for those in the placebo (Ms = −1.72 & −0.68 µV, respectively), t(1923) = −4.73, p < .001, and control groups (Ms = −2.46 & −1.89 µV, respectively), t(1923) = −2.32, p < .05. Critically, the Group × 2-back accuracy × Current trial type interaction was not significant, F(2, 1923) = 1.48, p = .23. Planned comparisons confirmed that incompatible arrays elicited larger FSW amplitude than compatible arrays two trials following correct responses and errors in all groups (see Table 2, bottom).
