Symbolic control of attention: tracking its temporal dynamics.

Three experiments examined the temporal dynamics of the impact of symbols with task-irrelevant spatial meanings on attentional control. In Experiments 1 and 2, participants were color-cued to report the first letter they saw in the left or right of two parallel letter streams. The cue appeared in the shape of an arrow pointing to the target stream (compatible) or to the other stream (incompatible). Incompatible arrows delayed letter selection; that is, participants reported later-appearing letters and made more errors. In Experiment 3, the target stream was cued in advance, and yet, incompatible symbols delayed target selection. These findings suggest that the irrelevant meaning of symbolic stimuli can still penetrate and bias attentional top-down control, an observation that challenges available control theories.