Fig. 6.

Effects of categorical uncertainty. A: saggital section (y = −2) showing positive (red) and negative (blue) correlations with a regressor indexing categorical uncertainty (see methods). Dorsal medial frontal cortex (dMFC; 6, 12, 51; z score = 3.70; P < 0.05, whole-brain corrected) and insula (not shown; 42, 24, −3; z score = 4.11; P < 0.05, whole-brain corrected) showed positive correlations with uncertainty. A cluster in ventromedial prefrontal cortex (vmPFC) showed increased activity for easier perceptual decisions (6, 36, 30; z score = 4.20; P < 0.05, whole-brain corrected). B: hemodynamic response timecourses for the 3 different cost conditions, plotted for the significant cluster in dMFC. While showing strong correlations with the categorical uncertainty regressor, this region was insensitive to changes in category value (cf. Fig. 3B).