The confidence-noise confidence-boost (CNCB) model of confidence rating data
Fig 5
Effect of multiple difficulty levels on Type 2 ROC.
(A) Psychometric function from six stimulus strengths chosen to be equally spaced between and
. In this figure, sensory noise is
and sensory criterion is
. (B) For each stimulus strength, confidence probability is plotted for each confidence level (‘high’ and ‘low’). Blue bars represent ‘Right’ perceptual responses, and orange bars ‘Left’ responses (running downwards). In this figure, confidence noise is
and confidence boost is
. (C) The sensory evidence for each stimulus strength has an associated confidence evidence. The full bivariate distribution of sensory and confidence evidence is shown for one of the six stimulus strengths. Positive stimulus strengths are shown in solid lines, negative ones in dotted lines. (D) When the observer is unbiased (
), there are now three Type II ROC curves. The three dots correspond to the Type 2 hit and false alarms rates obtained when the confidence boundary was set to equate the overall fraction of high and low confidence ratings (
) over all six stimulus strengths.