THE EFFECTS OF INCONGRUENT PROBABILITY, RESPONSE MODE, AND STIMULUS SET ON RT
Groups of participants identified the color of color-word stimuli either by typing the first letter of the color name or by saying it out loud. Half the groups saw congruent and incongruent stimuli; the others saw neutral and incongruent stimuli. Incongruent probability varied between groups from 0.25 to 0.86 in six steps. Incongruent inhibition was significant in all conditions but was greater with typing and with congruent stimuli. Inhibition decreased linearly with increasing incongruent probability. Color identification process remained stable as incongruent proportion increased, but word identification process was reduced, partially supporting process dissociation. Neutral RT with typing was usually faster when preceded by a neutral stimulus than an incongruent stimulus about half the time. The preceding stimulus had little effect on incongruent RT. Relevant dimensional changes slowed RT more than irrelevant ones. Results suggest stimulus-response compatibility, color-word process dissociation, and priming are the important mechanisms for modeling color-word responses.