With Or without a Hole: Young Infant's Sensitivity for Topological

Evidence from adult psychophysics, brain imaging, and honeybee's behavior has been reported to support the notion that topological properties are the primitives of visual representation (Chen, 1982). The present study aims to explore the question of how the sensitivity to topological property might originate during development. Specifically, we tested 1.5- to 6-month-old infants' visual sensitivity for topological versus geometric properties with the forced-choice novelty preference technique. A disk and a ring were used in the topologically-different condition (Exp. 1), while a disk and a triangle were used in the geometrically different condition (Exp. 2). The results showed that infants could reliably discriminate stimuli based on topological differences, but failed to do so based on geometric differences. Moreover, infants preferred the topologically-different figure (the ring) in the test phase of the generalization task. Further analysis on individual infants' age and performance revealed two distinct developmental trends. Infants seem to be sensitive to topological differences as young as 1.5 months while their ability to discriminate geometric differences was at chance before 3 months and gradually improves with age. Taken together, our findings suggested an early sensitivity for topological property, at least for the detection of stimuli with or without a hole