Schematic Diagram of the Procedure and Stimuli in the Experimental Tasks.

<p>In the change detection task (A), participants were presented with arrays of two, four, six, or eight colored squares (memory array). After a retention interval they indicated whether the color of the test probe matched or did not match the color of the original memory item in that location. In the attentional capture task (B), participants reported the orientation of the Landolt C that had been presented in the target color (red). In one third of the trials, a flanker (a task-irrelevant colored box) was presented before the search array; in two thirds of the trials, no flanker was presented. In half of the flanker-present trials the flanker was drawn in the target color (relevant-colored flanker), in the other half the flanker was green (irrelevant-colored flanker). The stimulus onset asynchrony (SOA) between the flanker and the search array varied across trials. The duration of the search array was titrated for each participant.