Cornelissen, FransVigário, RicardoMartins, Joana Isabel Faustino2020-02-172020-02-172019-102019http://hdl.handle.net/10362/92879Glaucoma is a disease resulting from damage at the optic nerve, the “highway” through which visual information travels from the retina towards the visual brain. Such lesion deprives the visual cortex of the regular input, causing interruptions within the visual field – scotoma. However, even when such lesions occur, perception remains stable as the human visual system perceptually masks the insult with the visual features of nearby regions of the visual field. To unravel the neural mechanisms by which this remarkable capacity occurs in glaucomatous individuals, we used functional magnetic resonance imaging (fMRI) and neural modelling to track changes in cortical population receptive fields (pRFs). We found that visual neurons from early visual areas (V1-3) expanded their pRFs both inside and at the vicinity of the lesion. V1 pRFs also shifted their preferred central position towards the outside of the scotoma. By doing so, neural populations were able to process information from spared visual field, consistent with the notion of predictive masking. In contrast, well-sighted observers did not show similar patterns of neural activity in response to the introduction of an artificial scotoma (AS). Our findings provide evidence of enduring cortical reorganization underlying the predictive spatial masking of scotomas in glaucoma, meeting the contemporary view that early visual areas of the adult human brain retain plastic mechanisms. Furthermore, the involvement of the brain suggests that glaucoma pathogenesis goes beyond the eye.engglaucomamaskingpopulation receptive fieldreorganizationfMRImaster thesis