Illustration of the sequential sampling approach.

The displayed model predictions refer to the example trial in Figure 1A. Each panel represents a choice accumulator over the course of the whole trial (upper panel = buy, middle panel = reject, lower panel = decision not to decide). The colored lines refer to the decision thresholds, the thick black lines to the average position of the decision variables (DV). The DV varies by Gaussian noise such that the model specifies the time point of the choice probabilistically. At the bottom of the three x-axes the model predictions for the models M1_standard (gray line) and M1*_evidence (black line) are depicted. The two models differ from each other by (not) assuming the existence of the third accumulator.