Figure 6.

Analysis of right rlPFC activity using alternative GLMs (see Materials and Methods). A, Model 2 separated trials into correct and incorrect to assess whether error-related activity could account for effects of confidence. Parameter estimates (arbitrary units) are shown both for average activity during confidence rating (light gray) and the confidence parametric modulator (dark gray). Neither comparison revealed significant differences between correct and incorrect trials. B, Model 3 orthogonalized confidence with respect to reaction time, demonstrating that the effect of reported confidence remained after controlling for the variance in activity accounted for by RT. **p < 0.01; *p < 0.05. Error bars reflect the SEM.