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.