Symmetry, complexity and perceptual economy: Effects of minimum and maximum simplicity conditions

Abstract

According to Gestalt theory, the perceptual system works on economic principles and tends to reach the maximum efficiency (i.e., increase of quality, goodness, and accuracy) with minimum invested energy (i.e., reduction of processing load). In this study the effects of two concurrent stimulus constraints, symmetry and simplicity, were investigated with the following variables related to perceptual economy: Goodness judgement (Experiment 1), completion of semi-structured patterns (Experiment 2), duration of search for target patterns (Experiment 3), and the duration and accuracy of pattern detection (Experiment 4). The results suggest that the dominance of symmetry or simplicity depends upon the difficulty of the experimental task. Symmetry prevailed in less restrictive, more interesting, and easier perceptual tasks, such as goodness judgement and pattern completion (Experiments 1, 2, and, partly, Experiment 3), whereas simplicity prevailed in difficult and restricted conditions, such as the detection of briefly exposed stimuli (50 ms; Experiment 4). The results are discussed in the context of Koffka's concept of minimum and maximum simplicity. When the perceptual system has a small energy disposal, or when external conditions are difficult and restricted (minimum simplicity conditions), simplicity in stimulus pattern organization will be preferred. When the perceptual system has a large amount of energy, or when external situations are unrestricted and interesting (maximum simplicity conditions), fine and regular articulations of stimulus patterns will be preferred. Our study confirmed the prediction implied by the concept of minimum and maximum simplicity.