BAYESIAN RETINOTOPIC INFERENCE OF VISUAL FIELD REPRESENTATIONS FOR CLINICAL APPLICATION IN AGE-RELATED MACULAR DISEASES

Advanced forms of age-related macular diseases (AMD) cause central vision loss and the formation of a lesion projection zone (LPZ) in the visual cortex, complicating the interpretation of fMRI data. Absent or unreliable foveal signals challenge population receptive field (pRF) modelling and limit pRF-based characterization of preserved peripheral vision. To address these issues, this methodological study combines pRF-based retinotopic mapping with Bayesian retinotopic inference to quantify visual field representations using artificial scotoma on healthy individuals. Retinotopic responses from two participants were first estimated using pRF modelling, adapted to altered visual input, allowing identification of cortical regions corresponding to the LPZ and surrounding peripheral representations. A Bayesian inference framework integrating retinotopic measurements with an anatomically defined retinotopic prior was then applied to reconstruct topologically coherent maps despite incomplete central data. This approach generated retinotopic representations reflecting LPZ-related alterations across early visual cortex and enabled quantification of deviations between simulated patient-specific maps and the anatomical prior. Results indicate that Bayesian inference improves the stability and completeness of retinotopic maps in simulated AMD compared to data-driven pRF estimates alone, particularly near the LPZ boundary. While large-scale retinotopic organization in peripheral cortex remains broadly consistent with the prior, localized deviations were observed adjacent to the deprived central field, providing a quantitative measure of altered structure–function relationships in AMD. Collectively, these findings demonstrate the feasibility and added value of Bayesian retinotopic mapping for clinical populations with central vision loss and establish a framework for characterizing the functional organization of spared visual cortex in AMD.