A popular metaphor in the Stroop literature derives from the notion of automaticity. This is the horse race model of interference. In this phenomenon, the Stroop effect is characterized as a race between two responses, one of which (the word) is processed faster than the other (the ink color). This preserves the relative speed idea. In the case of BLUE printed in red ink, blue arrives at the output buffer before red does, even when the required response is red. Although the race starts at the same time, word information is processed faster than color information; thus, once information gets to the finish line, the two responses must compete for control. For congruent stimuli, there is no response competition since the word and color information
