Fig 3. Brain activity during decision-making and feedback.

(A) Brain activity during decision-making. The reward magnitude (R_W, yellow) of the chosen option is related to the activity in the ventral striatum (CTD Z = 3.1, cluster corrected p-value < 3e-8, for visualization threshold Z = 4). The degree of ambiguity (P_a, blue) correlates with the IPS and the PCC (cluster corrected p-value < 1e-10), among other areas. The probability assigned during ambiguity correlated with the right IPS (light blue, P_all[A > nA]:contrast P_all during ambiguity > P_all during no-ambiguity condition, corrected p-value = 0.0002). Underestimating uncertainty (red, P_{all(τi = 0)} calculated with τ_i = 0) correlated bilaterally with the IPS (corrected p-value = 0.0003) and the PCC (corrected p-value < 1e-10). Objective uncertainty (green, P_{all(τi = 1)} calculated with τ_i = 1) correlated with the IPS, the PCC, the somatosensory area in the left hemisphere, and the SMA (all corrected p-value < 1e-10). (B) Brain activity during feedback. The fact of winning (Win, yellow) correlated with ventral striatum activity (CTD Z = 3.1, cluster corrected p-value < 1e-5, for visualization threshold Z = 4). The probability prediction during ambiguity (uPE-P_all[A], red) correlated with activity in the MCC (CTD Z = 3.1, cluster corrected p-value < 1e-5). Contextual brain connectivity (PPI) (IPS seed from P_all[A > nA] contrast) showed that the ambiguity condition generates an increase in the correlation between the IPS and several brain regions, including the MCC and the ventral striatum. See also S2 Table. The data underlying this figure can be found at https://osf.io/zd3g7/. CTD, cluster threshold detection; IPS, intraparietal sulcus; MCC, midcingulate cortex; PPI, psychophysiological interaction.