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Recognition of global and local aspects of a visual scene has been shown to rely on the analysis of the spatial frequencies (SF) constituting the visual scenes.Global information would be preferentially conveyed by low spatial frequencies (LSF) (magnocellular pathway) whereas local information would be conveyed by high spatial frequencies (HSF) (parvocellular pathway).Behavioural as well as neuroimaging studies have emphasized a hemispheric specialization for spatial frequency processing with the left middle occipital gyrus particularly implicated when processing HSF, whereas the right occipito-temporal area is particularly implicated when processing LSF.Using the same kind of paradigm in patients with peripheral or cortical visual deficits, we were able to show that even when visual acuity recovered, patients with (right or left) optic neuritis continue to exhibit altered LSF processing consistent with a dysfunction of the magnocellular pathway.Using fMRI we found that in patients with left optic neuritis, LSF was associated with a large network including occipital and parietal areas whereas no specific network was observed for HSF.Conversely, in patients with fight optic neuritis, no specific network was observed when LSF were processed whereas HSF was associated with increased activation in parietal and frontal areas.In patients with homonymous hemianopia, performance also depends on the lesion side, the visual field stimulated and the task.A fight occipital lesion altered LSF processing whereas HSF processing remained almost unaffected.In addition, using the same paradigm with fMRI revealed a different cerebral reorganization depending on the lesion side.Whereas right hemianopes recruited only the intact hemisphere, left hemianopes recruited both hemispheres to complete the recognition task.The present findings raise the question of specific cortical plasticity following the visual system lesion site and side.