Effect of Compatibility of S-R Mapping on Reactions toward the Stimulus Source

Abstract

The purpose of this research was to gain a better understanding of some of the factors which affect the speed of translating information from a visual display into an appropriate control action. The research focused on the concept of “logical recoding” proposed originally by Hedge and Marsh (1975) to explain the results of their study concerning the effect of an irrelevant directional cue (location of a stimulus) on choice reaction time to a relevant symbolic cue (color of the stimulus). Their subjects pressed a green or red key located on the left and right in response to the onset of a green or red stimulus presented in either a left or right window. When subjects were instructed to press the key which was the same color as the stimulus, they reacted faster when the location of the stimulus and response corresponded than when they did not. Hedge and Marsh used the label “Simon effect” to refer to this finding (Simon, 1969; Simon, 1970). The interesting aspect of the Hedge and Marsh findings was that when subjects were instructed to press the alternate colored key, reactions were faster when the location of the stimulus and response key did not correspond than when they corresponded. In other words, reversing the compatibility of S-R mapping produced a reversal of the Simon effect. Hedge and Marsh explained this reversal in terms of logical recoding; i.e., they proposed that with incompatible S-R mapping instructions, subjects recoded the irrelevant location cue as well as the relevant symbolic cue, thus causing them to respond faster on the side opposite the location of the stimulus.