Production and perception rules underlying visual patterns: effects of symmetry and hierarchy

Abstract

Formal language theory has been extended to two-dimensional patterns, but little is known about two-dimensional pattern perception. We first examined spontaneous two-dimensional visual pattern production by humans, gathered using a novel touch screen approach. Both spontaneous creative production and subsequent aesthetic ratings show that humans prefer ordered, symmetrical patterns over random patterns. We then further explored pattern-parsing abilities in different human groups, and compared them with pigeons. We generated visual plane patterns based on rules varying in complexity. All human groups tested, including children and individuals diagnosed with autism spectrum disorder (ASD), were able to detect violations of all production rules tested. Our ASD participants detected pattern violations with the same speed and accuracy as matched controls. Children's ability to detect violations of a relatively complex rotational rule correlated with age, whereas their ability to detect violations of a simple translational rule did not. By contrast, even with extensive training, pigeons were unable to detect orientation-based structural violations, suggesting that, unlike humans, they did not learn the underlying structural rules. Visual two-dimensional patterns offer a promising new formally-grounded way to investigate pattern production and perception in general, widely applicable across species and age groups.

Studying aesthetics with the method of production: Effects of context and local symmetry.

“…The initial orientation of the tiles in the array was randomized in each trial and differently for each participant. There was no time limit for the production trials, and the participants received no specific task instructions, other than to change as little Symmetry along orthogonal axis: 1 Symmetry along diagonal axis: or as much as they liked in the initial random pattern, and click on a "Finish" button under the tile array when they were ready to move on to the next trial (Westphal-Fitch et al, 2012). In total, there were 18 production trials, which were divided into blocks of six.…”

Bayesian selection of grammar productions for the language of thought

“…The language of geometry, Geo, is a probabilistic generator of sequences of movements on a regular octagon like the one in Figure 1. The production rules of grammar Geo were selected based on previous claims of the universality of certain human geometrical knowledge (Dehaene, Izard, Pica, & Spelke, 2006 (Machilsen, Pauwels, & Wagemans, 2009;Westphal-Fitch, Huber, Gómez, & Fitch, 2012). With these production rules, sequences are described by concatenating or repeating sequence of movements in the octagon.…”

A psycho-historical research program for the integrative science of art

“…Humans prefer to make, and perceive, patterns with a high level of symmetry and regularity (direct component). Creativity is also evident: participants often produced different pattern variants for the same tile array (Westphal-Fitch et al 2012).…”