Fig. 1.

Perceptual decision task and example psychophysics data. A: experimental procedure. Subjects viewed a cost signal screen informing them of the potential losses for an incorrect face or house categorization at the start of each trial. They were then asked to categorize an image randomly drawn from the face-house phase continuum as a “face” or “house.” Timings shown are for the fMRI experiment. B: illustrative psychophysics data from 1 subject (LB). Crosses show choice probabilities for each stimulus phase and cost combination; lines show psychometric curves fit to the data.