Figure 1.

Schematic of experimental design. A, The adapted classification learning task. Participant made a manual response and received informative feedback. Note that the gender position could change from trial to trial but always fixed to a given stimulus. In this way, participants learned both the stimulus–outcome (“male” or “female”) and stimulus–response (“left” or “right” key press) association. B, The experimental conditions. Each stimulus was associated with a gender; half the stimuli were shown with the male symbol on the left and half on the right. The gray arrow indicates the correct response during training and reversal, which is shown to help demonstrate the reversal conditions but was not printed on the screen in the actual experiment. For NR trials, nothing was changed from training to reversal. For FR trials, only the outcome was changed during reversal: participants were required to relearn the outcome as well as to switch their response. For OR trials, both the outcome and the associated gender symbols changed; participants thus only needed to relearn the outcome without switching their response. For RR trials, only the associated gender symbol was changed; participants only needed to switch their response without relearning the outcome. C, The training procedure. Each isolated block represents one learning block, and the numbers inside represent the number of repetitions. The light gray represents the behavioral sessions, whereas the dark gray indicates sessions in which functional scans were acquired. T, Training; R, reversal learning.