Figure 1 .

Selective attention task design and behavior. The single-trial layout of the flanker task is shown above, in which participants viewed a centrally presented crosshair for 1500 ms and then were presented with 1 of the 4 arrow arrays shown. Upon presentation of the arrow array, participants were instructed to indicate the direction of the central arrow, regardless of congruency. The significant effect of congruency (i.e., the flanker effect) on reaction time (P < 0.001) is illustrated by the box-and-whisker plot on the bottom left. The scatterplot on the bottom right shows the relationship between chronological age (x-axis, in years) and the effect of congruency on reaction time (y-axis, in milliseconds), with the line of best fit and correlation coefficient for this relationship overlaid.