Fig. 2. Task for Experiment 1.

Each trial consisted of a fixation period (500 ms), stimulus presentation (500 ms), and untimed response period. The stimulus comprised of 49 circles each colored in one of four different colors (red, green, blue, and white). One of the colors (white in this example) was presented more frequently (16 circles; dominant color) than the other colors (11 circles each; nondominant colors). The task was to indicate the dominant color. Two conditions were presented in different blocks. In the four-alternative condition, subjects chose between all four colors. In a separate two-alternative condition, on each trial subjects were given a choice between the dominant and one randomly chosen nondominant color.