Eliminating, magnifying, and reversing spatial compatibility effects with mixed location-relevant and irrelevant trials

Abstract

Abstract Abstract. Regardless of whether stimulus location is relevant or irrelevant to a task, responses are faster and more accurate when stimulus location and response location correspond than when they do not. Stimulus– response compatibility (SRC) effects of this nature are robust and typically considered to be automatic consequences of stimulus-response associations that are either hard-wired or acquired through years of experience. An exception to the robustness of SRC effects has been shown to occur when compatible and incompatible mappings are mixed. In the present paper, we review the literature on mixing compatible and incompatible mappings and show that mixing does not always reduce the SRC effect. We then present results from studies in which location-irrelevant (LI) trials are mixed with location-relevant (LR) trials. The SRC effect for LR trials of physical locations to keypresses is eliminated when stimulus color, rather than location, is relevant on half of the trials. However, the SRC effect for LR trials is unaffected by mixing when the location information is conveyed by arrows and ampli1ed when it is conveyed by words. With vocal location responses, the SRC effects for all three stimulus types are enhanced by mixing.