Early emergence and later development of face, scene, and object regions revealed by natural vision

High-level visual cortex contains a stereotyped set of regions specialized for processing faces, scenes, and objects. How do these regions develop? Answering this question has proven challenging, given the difficulty of collecting fMRI data from young children – a problem exacerbated by reliance on relatively unengaging paradigms designed for adults. Here we addressed this challenge by studying responses to a short, engaging, animated movie depicting natural visual experience, which allowed high-quality data collection from a large sample (N=122) of children age 3-12 years. We first developed a method for defining face, scene, and object regions using movie data, and confirmed that this method accurately identifies subject-specific regions in adults. We then studied how adult regions responded during the video, and found that the content of movie events eliciting peak responses reflected the well-known selectivity of each region for faces, scenes, or objects. Adults also showed stronger interregional correlations between regions with more similar functions (e.g., two scene regions) than regions with distinct functions (e.g., a face and a scene region). Having characterized responses in adults, we next tested for this same functional organization in children. Remarkably, adult-like function was already detectable across face, scene, and object regions by just 3 years of age, with children showing peak responses to similar movie events, and similar patterns of interregional correlations, as adults. Later in development, the magnitude of responses to peak events continued to increase, with individual regions following distinct trajectories. For example, the fusiform face area showed relatively little change across childhood, whereas the posterior superior temporal sulcus showed clear evidence of protracted developmental change. Taken together, these results reveal that adult-like function emerges in face, scene and object regions within the first three years of life, yet continues to be refined along distinct trajectories in specific regions across childhood.