Figure 1.

After a fixation cross, flanker faces (congruent or incongruent with the target) were shown alone for 80 ms and then together with the target for 30 ms more. Participants were instructed to indicate with a button press whether the target was upright or upside down. They could press a different button if they were uncertain. After a jittered time interval, participants rated their previous response (accuracy rating) by pressing the same button again (correct), the opposite button (incorrect), or the uncertain button.