In all conditions, observers were required to select two target characters and determine whether they were of the same (i.e., both letters or both digits) or different category (i.e., letter and digit). (A) The target colors were cued once in the beginning of a block and stayed constant for the rest of the block (64 trials). A trial started with a fixation screen for a jittered interval of 850 to 950 ms, followed by the search display, presented for 50 ms and another fixation screen that lasted for up to 2000 ms or until participants responded. Depending on the response, feedback was presented for 500 ms (‘correct’, or ‘wrong’). If no response was given, a 10 s time out occurred and participants were urged to try responding quicker. (B) Task design. Depending on the condition, either one or two colors were cued to be task-relevant in the beginning of a block (creating one vs. two unique templates). Similarly, whenever two colors were cued, search displays could contain either one of them, or both (one vs. two unique target features). Thus, in the one-template-one-target-feature condition (1TMP–1TGT) one color was cued, and both targets carried this color in the search display, in the two-templates-one-target-feature condition (2TMP–1TGT) two colors were cued but only one of these colors was present in the search display with both targets carrying that color, and in the two-template-two-target-feature condition (2TMP–2TGT) two colors were cued and both colors were present in the search displays. One target always appeared on the horizontal meridian (above or below fixation), and the other target on the vertical meridian (to the left or right of fixation). (C) and (D) Behavioral results. The violin plots depict the distribution of (C) accuracy (see Figure 1—source data 1) and (D) response times (see Figure 1—source data 2) across participants, separately for the 1TMP–1TGT, 2TMP–1TGT, and 2TMP–2TGT conditions. The horizontal lines in the box plots represent quartiles. The vertical line represents the minimum (lower quartile - 1.5 * interquartile range) and maximum (upper quartile + 1.5 * interquartile range) while single dots beyond that range indicate individual outliers.