Wednesday, April 2, 2025
4/2/2025
Development of Human Dorsal Visual Cortex - PROJECT SUMMARY The dorsal visual stream is one of the two major processing pathways in human visual cortex, and is involved in attentional and spatial aspects of vision critical for attending to, filtering, and interacting with the visual environment. The retinotopic maps which comprise the dorsal visual stream have never been mapped across development. This is a fundamental gap in the neuroscience of vision, with no existing models for how the structural and functional development of a major visual processing pathway drives behavioral maturation. Leveraging our prior working in population receptive field (pRF) mapping of ventral visual stream development, we propose a rigorous multimodal approach combining functional magnetic resonance imaging (fMRI), quantitative MRI (qMRI), neuroanatomical mapping, and the innovative use of bespoke video game-based experiments to engage children to measure the dorsal visual stream in childhood, adolescents, and adults. Collecting multiple forms of data on each individual allows us measure how simultaneous changes in function and fine-scale tissue structures in the living brain are coordinated to impact behavioral development. The work is structured around three aims. Aim 1 will produce two developmental atlases of the dorsal visual stream: a functional atlas defining how dorsal stream maps of visual space are organized, and a structural atlas charting fine-scale tissue development in the same maps unfolds across neurotypical development. Using fMRI, qMRI, and behavioral measures, we quantify how the growth or loss of visual space representations across development in parietal cortex is related to changes in tissue structures such as myelin and neuropil density, and how each of these relate to the development of visuospatial attention. Aim 2 will determine how broader functional tuning of the dorsal visual stream matures. Using fMRI and behavioral metrics, we will perform pRF modeling to quantify how representations of space, motion, and numerosity differ between children and adults. Aim 3 will quantify how the visual ability to dynamically shift the locus of spatial attention is constrained by functional development of the dorsal stream. Using fMRI and a novel game-based experiment, we overcome hurdles to engage children in a task in which spatial attention is paramterically altered to determine how dynamic properties of receptive fields—their ability to change size and position—mature into adulthood and constrain ecological visual behaviors such as reading ability. Overall, these data will establish a normative trajectory of the dorsal visual stream's development, both structurally and functionally, filling longstanding gaps in visual neuroscience. A structural-functional atlas of visual cortex will equip researchers with a neurotypical model to better characterize visual disorders that likely result from atypical development of the dorsal visual stream, such as cortical visual impairment (CVI).
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).