Dimensional overlap accounts for independence and integration of stimulus—response compatibility effects

Extensive studies have been conducted to examine various attentional control effects that stem from stimulus— stimulus (S—S) and stimulus-response (S—R) incompatibility. Among these behavioral paradigms, the best-known are the Stroop effect, the Simon effect, and Posner’s cue validity effect. In this study, we designed two behavioral tasks incorporating these effects (Simon—color-Stroop and Simon-spatial-Stroop) guided by a general framework of S—R ensemble, the dimensional overlap theory. We analyzed various attentional effects according to dimensional overlaps among S—S and S—R ensembles and their combinations. We found that behavioral performance was independently affected by various dimensional overlaps in the Simon—color-Stroop task, whereas different sources of dimensional overlap in the Simon—spatial-Stroop task interacted with each other. We argue that the dimensional overlap theory can be extended to serve as a viable unified theory that accounts for diverse attentional effects and their interactions and helps to elucidate neural networks subserving attentional control.