neutral crosshair is presented for 3 s, such that the total trial length is 7 s. One incongruent trial (e.g. a negative-feedback trial within a predominantly positive block) was included within each block to maintain task engagement and motivation and prevent participants from anticipating trial feedback. Three control blocks are interleaved between the six experimental card-guessing blocks, during which participants are instructed to make button presses during the 3-s presentation of an ‘x,’ which is then followed by an asterisk and a yellow circle (presented for 500 ms each). Participants were unaware of the fixed outcome probabilities and were led to believe that their performance would determine their net monetary gain. All subjects received $10 upon completion of the task.
