Fig. 1.

Probabilistic reversal task. Participants were asked to choose between a winter and summer item (A) according to their belief that the current season was either summer or winter. Correct seasonal choices (and correct deliveries) resulted in 87% of the trials in a profitable or unprofitable sale [happy or sad face in (D), respectively]. To balance gains and losses, the delivery service (C) would not always bring the desired item. Moreover, half of the trials were uninformative for learning about the current season (i.e., did not allow a choice between winter or summer items). After every trial, participants were asked to rate how sure they were that the current season was summer or winter (E). Background, font color, as well as pictures where adjusted to an overall luminance of 0.5 to allow for continuous pupillometric recordings. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)