Fig. 1.

Trial structure of task. Participants were presented two wheels (gambles) that differed with respect to the magnitudes and probabilities of outcomes, and asked to select one. After wheel choice, participants were shown how many points they won or lost and were asked to rate how pleased or disappointed they felt by that outcome (rating 1; partial feedback). Then, participants were shown how many points they could have won or lost if they had chosen differently (i.e., selected the other wheel) and were asked to rate how pleased or disappointed they felt knowing their outcomes compared with the other wheel (rating 2; complete feedback). The complete list of trials presented to participants is provided in Table S3. Equations represented here illustrate the mapping of these parameters onto information about each wheel provided to participants. d, Disappointment; e, expected value (EV); r, regret.