Plasticity of the human visual brain after early cortical lesion

Publication date: Available online 31 October 2017 Source:Neuropsychologia Author(s): K. Mikellidou, R. Arrighi, G. Aghakhanyan, F. Tinelli, F. Frijia, S. Crespi, F. De Masi, D. Montanaro, M.C. Morrone In adults, partial damage to V1 or optic radiations abolishes perception in the corresponding part of the visual field, causing a scotoma. However, it is widely accepted that the developing cortex has superior capacities to reorganize following an early lesion to endorse adaptive plasticity. Here we report a single patient case (G.S.) with near normal central field vision despite a massive unilateral lesion to the optic radiations acquired early in life. The patient underwent surgical removal of a right hemisphere parieto-temporal-occipital atypical choroid plexus papilloma of the right lateral ventricle at four months of age, which presumably altered the visual pathways during in utero development. Both the tumor and surgery severely compromised the optical radiations. Residual vision of G.S. was tested psychophysically when the patient was 7 years old. We found a close-to-normal visual acuity and contrast sensitivity within the central 25° and a great impairment in form and contrast vision in the far periphery (40–50°) of the left visual hemifield. BOLD response to full field luminance flicker was recorded from V1 and in a region in the residual temporal-occipital region, presumably corresponding to MT+, of the lesioned (right) hemisphere. A population receptiv...
Source: Neuropsychologia - Category: Neurology Source Type: research