Fig. 1.

Task sequence. Participants do a coin-flip guessing task. In the NoOP trials, participants were instructed to record their prediction about the upcoming coin flip when the word ‘Press’ appeared on the screen by pressing a button labeled ‘H’ if they predicted ‘head’ and a button labeled ‘T’ if they predicted ‘tail’. In the Op trials, participants made their predictions privately: instead of the ‘Head’ and ‘Tail’ in the NoOP trials, the word ‘Random’ would appear and the participants would press the ‘R’ key to indicate they finished their prediction. The ERPs were locked to the outcome cue screen (marked with a red box).