Figure 1.

Experimental design. A, Example time line of a single trial. Observers responded with their decision confidence whether the cued target object was present or absent using an 8-point confidence scale. To dissociate decision from motor responses we presented a color cue (red square or green triangle), randomized on a trial-to-trial basis, which indicated the mapping between the observer's hands and the confidence rating. B, Target-absent images were deliberately selected to contain a contextual location that was lateralized either toward the left (i, iii) or right (ii, iv) of the image. C, Examples of target present stimuli.