Effects of stimulus -set location on orthogonal stimulus -response compatibility

Yang Seok Cho, Purdue University

Abstract

Stimulus-response compatibility (SRC) effects occur when stimulus and response sets are arrayed orthogonally. Two types of orthogonal SRC effect are found, an overall up-right/down-left advantage and orthogonal mapping preferences that vary with response factors such as response location and hand posture. Umiltà's (1991) dual-strategy hypothesis and Lippa and Adam's (2001) end-state comfort hypothesis assume that these two types of the effect have different underlying mechanisms. Moreover, because the end-state comfort hypothesis emphasizes the state of the motor system to explain the latter type of effect, it predicts that the orthogonal SRC effect should be dependent on response mode. In contrast, because Weeks and Proctor's (1990) salient features coding hypothesis attributes the effects to the asymmetry of spatial codes, it predicts that the orthogonal SRC effect should not depend on response mode. The present study investigated whether the location of the stimulus set influences the orthogonal SRC effect and whether the effects are qualitatively similar for different response modes. Experiments 1 and 2 showed that the orthogonal SRC effect was not influenced by the location of the stimulus set when it varied along the same dimension as the stimulus alternatives. Experiments 3 and 4, in which the location of the stimulus set was varied along the same dimension as the response alternatives, showed that the orthogonal SRC effect was influenced by the response location relative to the stimulus set. In addition, the effect of response location on the orthogonal SRC effect was independent of stimulus-onset asynchrony, whereas a spatial correspondence effect for the irrelevant stimulus-set location and response varied as a function of SOA. In Experiment 5, the orthogonal SRC effect was determined by the response location relative to the location of the stimulus set, rather than the hand position in terms of body midline, in all response modes. These results provide evidence for the view that the orthogonal SRC effect varies as a function of response location rather than hand position. Only the salient features coding perspective provides an explanation for the results showing that the orthogonal SRC effect is influenced by the response location regardless of response mode.

Degree

Ph.D.

Advisors

Proctor, Purdue University.

Subject Area

Cognitive psychology|Experimental psychology|Psychology

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