The Stroop task (Stroop, 1935) required inhibiting a prepotent word reading response in favor of a color categorization response. In each of 180 trials (split into four mixed-trial blocks), participants named, as quickly and accurately as possible, the color (red, green, blue, orange, yellow, or purple) of the stimulus. The stimulus could be any one of three equally probable types: a colored string of asterisks, a color word printed in an incongruent different color (e.g., blue printed in red), or a colored neutral word (e.g., ship). The dependent measure was the difference between the average incongruent trial RT and the average asterisks trial RT.
