Proceedings of the Annual Meeting of the Cognitive Science Society

Humans' sensitivity to geometric structure begins to emerge in infancy. However, representational strategies underlying infant shape processing remain unknown. Do infants encode shapes through abstract combinations of geometric primitives, or do they rely primarily on low-level perceptual features? To address this question, we examined shape processing in 10–12-month-olds using a novel eye-tracking intruder task. Infants viewed arrays of 4 geometric shapes consisting of 3 standard and 1 deviant shape. Shapes varied in regularity and number of sides/angles (equilateral triangle, isosceles triangle, square, rhombus, regular pentagon). We assessed whether shape complexity influenced deviant detection, defined as the proportion of looking time to the deviant shape. Results revealed a significant effect of shape, with above-chance deviant detection only for squares and real-world objects. This selective success suggests that infants' geometric representations may be sensitive to particular structural properties (e.g. right angles, symmetry, parallelism), rather than reflecting a fully-fledged combinatorial system of geometric primitives.