Mechanisms of judgments in perception-action relations: Representational affordance or holistic processing?

Dongbin Cho, Purdue University

Abstract

The object-based Simon effect refers to the finding that choice reactions are often faster when the location of the graspable part of an object corresponds with the location of the response than when it does not. Several experiments have suggested that different types of judgment influence the performances differently. Some argue that affordances for action are activated when an action-relevant property such as orientation or shape is judged, as distinct from a surface property such as color. However, perceptual research has suggested that processing of shape and orientation is fundamentally different from processing of color because the former is holistic but the latter is not. Thus, I proposed a holistic processing hypothesis as an alternative to the affordance hypothesis to evaluate the role of judgment type in object-based Simon effects. The hypotheses were tested in five experiments, using door-handle stimuli with the handle oriented to the left or right. In Experiment 1, color judgments showed a Simon effect relative to the base of the door handle, whereas shape judgments showed no Simon effect. Experiment 2 used stimuli for which only the handle was colored and found a Simon effect similar to that of the color condition of Experiment 1. In Experiment 3, when the tip or the base of the handle was colored, the Simon effect was obtained relative to the color location. When the middle of the handle was colored, the Simon effect was obtained relative to the base, implying that color processing isolates the salient part from the object. For Experiment 4, only the base was colored, and the Simon effect was larger for a passive rather than active handle state, as in the near-the-base color condition of Experiment 3. In Experiment 5, orientation judgments showed an absence of Simon effect, as the shape judgments did in Experiment 1. The findings of (a) an absence of Simon effects for shape and orientation judgments, (b) no larger Simon effects for active than passive handle states, and (c) isolation of the salient component for color judgments, converge to support the holistic processing hypothesis.

Degree

Ph.D.

Advisors

Proctor, Purdue University.

Subject Area

Behavioral psychology|Experimental psychology|Cognitive psychology

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