Suprathreshold perceptual decisions constrain models of confidence
Fig 2
A) Task design. Observers were shown dots drawn from a Gaussian generating distribution with seven possible horizontal spatial offsets between ±4° from the screen centre. They judged if the distribution mean was left or right of centre. After each pair of perceptual decisions (Interval 1 and Interval 2), they reported the interval in which they had higher confidence in their decision. There were six levels of stimulus uncertainty, defined by information quantity (number of dots: 2 or 5) and quality (sampling distribution SD: 1.5, 2, or 2.5°), presented in an interleaved design. B) Occurrence of unique stimulus sets (colour coded). Squares: stimulus set in a single session. Sets are ordered by type, not session order, and participants by frequency of stimulus set repeats (5-pass to 1-pass).