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

According to Gestalt theory, the perceptual system works on economic princi ples and tends to reach the maximum efficiency (i.e., increase of quality, goodness, and accuracy) with minimum invested energy (i.e., reduction of pr ocessing load). In this study the effects of two concurrent stimulus constr aints, symmetry and simplicity, were investigated with the following variab les related to perceptual economy: Goodness judgement (Experiment 1), compl etion of semi-structured patterns (Experiment 2), duration of search for ta rget patterns (Experiment 3), and the duration and accuracy of pattern dete ction (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 task s, such as goodness judgement and pattern completion (Experiments 1, 2, and , partly, Experiment 3), whereas simplicity prevailed in difficult and rest ricted conditions, such as the detection of briefly exposed stimuli (50 ms; Experiment 4). The results are discussed in the context of Koffka's concep t 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 organizatio n will be preferred. When the perceptual system has a large amount of energ y, or when external situations are unrestricted and interesting (maximum si mplicity conditions), fine and regular articulations of stimulus patterns w ill be preferred. Our study confirmed the prediction implied by the concept of minimum and maximum simplicity.