Figure 3.

Neural correlates of single-update and double-update prediction error processing. (a) Across both groups, peak conjoint activity elicited by PE_SU and PE_DU was observed in the ventro-medial prefrontal cortex (vmPFC, X=-6 Y=52 Z=-12, t=4.86, p-FWE for the whole brain=0.03, see Supplementary Table S6). (b, c) Comparing PE_SU and PE_DU between groups revealed significantly reduced activation associated with of PE_DU signatures in BED in the medial prefrontal cortex (X=−12, Y=40, Z=−6, t=4.06, FWE-corrected for vmPFC p=0.03). For display purposes, threshold is set at p<0.001, cluster level k=10. (d) Parameter estimates at the peak-coordinate of the group difference in vmPFC for PE_DU were extracted and, for both groups separately, correlated with behavioral performance (percentage of correct choices, percentage of switching). This revealed a significant positive association between activation associated with PE_DU and correct choices in both, BED (r=0.60, p=0.005) and HC (r=0.53, p=0.02). The correlation between PE_DU related activation and switching was significant (r=−0.35, p=0.03) and did not indicate any evidence for an interaction effect with group (t<1.41, p>0.17, R² change due to moderator<0.03). PEs, prediction errors; BED, binge eating patients; DU, double update; HC, healthy controls; SU, single update.