Visual activation of extra-striate cortex in the absence of V1 activation

NEUROPSYCHOLOGIA

卷:48

Article

Bridge, Holly^1,2  Hicks, Stephen L.²  Xie, Jingyi¹  Okell, Thomas W.¹  Mannan, Sabira²  Alexander, Iona³  Cowey, Alan³  Kennard, Christopher² 

[1] Univ Oxford, John Radcliffe Hosp, FMRIB Ctr, Oxford OX3 9DU, England

[2] Univ Oxford, John Radcliffe Hosp, Dept Clin Neurol, Oxford OX3 9DU, England

[3] Univ Oxford, Dept Expt Psychol, Oxford OX1 3UD, England

关键词: Primary visual cortex;    Blind;    fMRI;    Lateral geniculate nucleus;    Structural imaging;   

DOI  :  10.1016/j.neuropsychologia.2010.10.022

来源: Elsevier

【 摘 要 】

When the primary visual cortex (VI) is damaged, there are a number of alternative pathways that can carry visual information from the eyes to extrastriate visual areas. Damage to the visual cortex from trauma or infarct is often unilateral, extensive and includes gray matter and white matter tracts, which can disrupt other routes to residual visual function. We report an unusual young patient. SBR, who has bilateral damage to the gray matter of V1, sparing the adjacent white matter and surrounding visual areas. Using functional magnetic resonance imaging (fMRI), we show that area MT+/V5 is activated bilaterally to visual stimulation, while no significant activity could be measured in Vi. Additionally, the white matter tracts between the lateral geniculate nucleus (LGN) and V1 appear to show some degeneration, while the tracts between LGN and MT+/V5 do not differ from controls. Furthermore, the bilateral nature of the damage suggests that residual visual capacity does not result from strengthened interhemispheric connections. The very specific lesion in SBR suggests that the ipsilateral connection between LGN and MT+/V5 may be important for residual visual function in the presence of damage to V1. (C) 2010 Elsevier Ltd. All rights reserved.

【 授权许可】

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