Visual object categorization in infancy

Humans make sense of the world by organizing things into categories. When and how does this process begin? We investigated whether real-world object categories that spontaneously emerge in the first months of life match categorical representations of objects in the human visual cortex. Taking infants looking times as a measure of similarity, we defined a representational space where each object was defined in relation to others of the same or different categories. This space was compared with hypothesis-based and fMRI-based models of visual-object categorization in the adults visual cortex. Analyses across different age groups revealed an incremental process with two milestones. Between 4 and 10 months, visual exploration guided by saliency gives way to an organization according to the animate-inanimate distinction. Between 10 and 19 months, a category spurt leads towards a mature organization. We propose that these changes underlie the coupling between seeing and thinking in the developing mind.