The item-specific proportion congruency effect is observed with a color-word verification task: ımplications for ıtem-specific control and stimulus-response contingency learning explanations

The item-specific proportion congruency (ISPC) effect is demonstrated by a smaller Stroop effect for mostly incongruent (MI) items compared to mostly congruent (MC) items. Currently, there is an ongoing debate regarding the contribution of automatic control processes and stimulus-response contingency learning processes to the ISPC effect. The aim of the present study was to further explore the cognitive processes underlying the ISPC effect. Specifically, the ISPC effect was investigated by using a color-word verification task. In this task, which is not a selective attention task, subjects indicate whether or not the presented word and the color match. Results revealed a significant ISPC effect. Importantly, compared to an equal congruency (EC) condition, response times were slower for the MI-congruent items, and faster for the MC-congruent items. Current findings can neither be explained by a pure item-specific control, nor a pure stimulusresponse contingency learning accoun