< Back to Article

The confidence-noise confidence-boost (CNCB) model of confidence rating data

Fig 2

Trade-off between confidence noise and confidence boost.

(A) Type 2 ROC. The blue dot shows the Type 2 hit and false alarm rates for the simulated human observer of Fig 1 (, , and ). The smooth blue curve corresponds to the theoretical ROC curve obtained with the same values of confidence noise and confidence boost, but by varying the value of the confidence boundary. The dashed green curve corresponds to another observer with different confidence noise and confidence boost ( and ), chosen such that Type 2 hit and false alarm rates are identical to the simulated human observer. Note that these two curves intersect in a single point (blue dot), and slightly differ outside this point. In fact, there is an infinite number of pairs of confidence noise and confidence boost that will give the same set of Type 2 hit and false alarm rates, as illustrated in panel B. (B) Equivalent pairs of confidence noise and confidence boost. Each coloured line represents an observer with a particular set of Type 2 hit and false alarm rates. The blue curve shows the pairs of confidence noise and confidence boost that are equivalent to the simulated human observer shown by the blue dot that was also the example shown in panel A. The black curve shows the equivalent pairs of confidence noise and confidence boost for the ideal confidence observer (i.e., for whom and ). The equivalent confidence noise is obtained when the confidence boost is set to 1, and is shown as a green dot for the human observer (), and as a black dot for the ideal observer (). The red and yellow curves are equivalent pairs of confidence noise and confidence boost for other simulated observers that are presented later in this paper, namely in red and in yellow.

doi: https://doi.org/10.1371/journal.pcbi.1012451.g002