Figure 8.

Brain activations in the decision phase. Relative decision value (A), a linear contrast of the regressors for relative (chosen − unchosen option) predicted reward magnitude + shown reward probability − predicted effort magnitude, led to increases (orange) and decreases (blue) in BOLD at the time of the decision. Regions activated in this contrast are regions in which activity is covarying with the value information that ought, rationally, to guide decision-making. Importantly, we also found increases in BOLD (B) in the vmPFC (beige) when a real rather than a hypothetical reward had been received on the last trial. vmPFC activity, therefore, covaries with an outcome feature that led to irrational biases in behavior. All results are cluster-corrected at p < 0.05.