In the standard Proportion-Congruent (PC) paradigm, performance is compared between a list containing mostly congruent (MC) stimuli (e.g., the word RED in the color red in the Stroop task; Stroop, 1935) and a list containing mostly incongruent (MI) stimuli (e.g., the word BLUE in red). The PC effect, the finding that the congruency effect (i.e.,…

In the Stroop task, congruency effects (i.e., the color-naming latency difference between incongruent stimuli, e.g., the word BLUE written in the color red, and congruent stimuli, e.g., RED in red) are smaller in a list in which incongruent trials are frequent than in a list in which incongruent trials are infrequent. The traditional explanation…