A Referential coding Explanation for Compatibility Effects of Physically Orthogonal Stimulus and Response Dimensions

This study addresses the dependence of compatibility effects on responding hand with horizontally oriented stimuli and vertically oriented responses (H-V effect) and with vertically oriented stimuli and horizontally oriented responses (V-H effect) reported by Bauer and Miller (1982). Experiment 1 replicated the H-V effect. In Experiment 2, the subject was instructed to respond with the hand in line with the response keys. That eliminated the H-V effect. In Experiment 3, the response board was placed to the left or right side of the subject, yielding a considerably reduced H-V effect and a novel compatibility effect dependent on board location. In Experiment 4, the V-H effect was produced when the subject was required to respond with the hand in line with the response keys. With the hand rotated through 90 in Experiment 5, the V-H effect was eliminated, and a main effect of mapping was observed. The results challenge Bauer and Miller's movement-preference hypothesis and support a referential-coding hypothesis proposed by the author. This assumes that response positions are coded in reference to hand posture, so that physically orthogonal stimulus and response dimensions can overlap with respect to their mental representations. The applicability of this hypothesis to other compatibility effects is demonstrated, and its significance for compatibility theories is briefly discussed.