Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss

• Type of Material: Article
• Authors: Daniel D Dilks, Emory University; Joshua B. Julian, University of Pennsylvania; Eli Peli, Harvard Medical School; Nancy Kanwisher, Massachusetts Institute of Technology
• Language: English
• Date: 2014-08
• Publisher: Lippincott, Williams & Wilkins
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: (C) 2014 American Academy of Optometry
• Final Published Version (URL): http://dx.doi.org/10.1097/OPX.0000000000000325
• Title of Journal or Parent Work: Optometry and Vision Science
• ISSN: 1040-5488
• Volume: 91
• Issue: 8
• Start Page: e199
• End Page: e206
• Grant/Funding Information: This work was supported in part by NIH grants EY016559 and EY13455 (NK), and EY05957 (EP).
• Keywords: retinotopy; adult visual system; cortical reorganization; primary visual cortex; cortical plasticity; human
• Research Categories: Health Sciences, Opthamology

Abstract

When individuals with central vision loss due to macular degeneration (MD) view stimuli in the periphery, most of them activate the region of retinotopic cortex normally activated only by foveal stimuli – a process often referred to as ‘reorganization’. Why do some show this reorganization of visual processing whereas others do not? We reported previously that six individuals with complete bilateral loss of central vision showed such reorganization, while two with bilateral central vision loss but with foveal sparing did not, and we hypothesized that the effect occurs only after complete bilateral loss of foveal vision. Here we conduct a stronger test of the dependence of reorganization of visual processing in MD on complete loss of foveal function, by bringing back one (called MD6) of the two participants who previously did not show reorganization, and who showed foveal sparing. MD6 has now lost all foveal function, and we predicted that if large-scale reorganization of visual processing in MD individuals depends on complete loss of foveal input, then we will now see such reorganization in this individual.