How do Cortical regions selective for visual scenes develop in human infants? - Project Summary The goal of the proposed work is to study the typical development of the critical ability to recognize and navigate the local visual environment, or ”scene”, which constitutes the bedrock of a healthy, independent, and productive life. A rich behavioral literature in humans has shown that remarkable spatial and navigational abilities are already develop- ing within the first few years of life. Likewise, extensive neuroimaging work has uncovered a network of brain regions dedicated to scene perception and navigation in adulthood. However, there is key knowledge gap about how these regions develop the human brain, particularly during the first year of life. Here we propose to study the typical devel- opment of scene-selective cortex in the awake infant brain using magnetic resonance imaging (fMRI) and functional near-infrared spectroscopy (fNIRS). Across three aims, we develop and test two competing theoretical frameworks. One framework suggests that early responses to scenes are driven by low-level visual information inherited from earlier visual systems, and that higher-level scene responses are built on these foundations via cumulative passive exposure to visual scenes over time. By contrast, the second framework suggests that early responses to scenes al- ready reflect higher-level information about the navigation-relevant features of scenes, influenced by connectivity with regions beyond the visual system, and that representations of the structure of the scene are specifically enhanced as infants begin to make independent choices of where to go and how. In Aim 1, we will use fMRI in 2-9 month old infants to test when responses to scenes depicting navigational affordances first emerge in the infant cortex; and whether connections guiding the development of the network are primarily from earlier visual areas, or also from areas beyond the visual cortex. In Aim 2, we will use fNIRS and wide-angle immersive displays in 5-11 month old infants to study whether early-emerging functional responses in this system are driven by low-level features (e.g., peripheral visual stimulation) only, or also by higher-level information about the functional relevance of scenes (e.g., for navigation). Finally, in Aim 3, we will quantify infants' ecological passive visual experience with scenes, and how that changes with motor development, in order to ask whether the onset of independent navigation specifically shapes the neural devel- opment of scenes, over and above passive visual experience. The results of this work will yield basic insights into the typical development of cortical scene processing, and shed light on the fundamental debate in development over the relative roles of maturation and experience. This work will also inform clinically focused investigations into how the basic developmental processes studied here go awry in developmental disorders, and hopefully, novel interventions and rehabilitation strategies for individuals who lose these abilities as a result of stroke or neurodegeneration.
