B.1.5.1.3. Procedure

First, a fixation cross appeared for 1000 ms, followed by a 500 ms black background. Then, the search display appeared until the participants responded according to the target's orientation (top or bottom). Participants performed three blocks (one for each condition: random, small-relevant and large-relevant) of 72 trials, in counterbalanced orders. In the random block, each size had the same 33% probability to be the target. In the small- (large-) relevant conditions, the small (large) item had a 67% probability to be the target, while each other square (i.e. the medium and large squares, or the medium and small squares, respectively) had the same 17% probability to be the target. The probabilities were explicitly stated to participants prior to each block of trials. Discarded trials accounted for less than 4 % of the total number of trials.