Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss
Purpose: 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 v...
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| Format: | Article |
| Idioma: | en_US |
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Ovid Technologies (Wolters Kluwer) - Lippincott Williams & Wilkins
2016
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| Accés en línia: | http://hdl.handle.net/1721.1/102441 https://orcid.org/0000-0003-3853-7885 |
| _version_ | 1826212490803937280 |
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| author | Dilks, Daniel D. Julian, Joshua B. Peli, Eli Kanwisher, Nancy |
| author2 | Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences Dilks, Daniel D. Julian, Joshua B. Peli, Eli Kanwisher, Nancy |
| author_sort | Dilks, Daniel D. |
| collection | MIT |
| description | Purpose: 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, whereas 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.
Methods: MD6 and two normally sighted control subjects were scanned. Stimuli were gray-scale photographs of objects presented at either the fovea or a peripheral retinal location (i.e., the MD participant’s preferred retinal locus or the control participants’ matched peripheral location).
Results: In MD6, visual stimulation at the preferred retinal locus significantly activated not only the expected “peripheral” retinotopic cortex but also the deprived “foveal” cortex. Crucially, MD6 exhibited no such large-scale reorganization 5 years earlier when she had some foveal sparing. By contrast, in the control participants, stimulation at the matched peripheral location produced significant activation in peripheral retinotopic cortex only.
Conclusions: We conclude that complete loss of foveal function may be a necessary condition for large-scale reorganization of visual processing in individuals with MD. |
| first_indexed | 2024-09-23T15:22:30Z |
| format | Article |
| id | mit-1721.1/102441 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:22:30Z |
| publishDate | 2016 |
| publisher | Ovid Technologies (Wolters Kluwer) - Lippincott Williams & Wilkins |
| record_format | dspace |
| spelling | mit-1721.1/1024412022-09-29T14:34:08Z Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss Dilks, Daniel D. Julian, Joshua B. Peli, Eli Kanwisher, Nancy Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences McGovern Institute for Brain Research at MIT Kanwisher, Nancy Purpose: 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, whereas 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. Methods: MD6 and two normally sighted control subjects were scanned. Stimuli were gray-scale photographs of objects presented at either the fovea or a peripheral retinal location (i.e., the MD participant’s preferred retinal locus or the control participants’ matched peripheral location). Results: In MD6, visual stimulation at the preferred retinal locus significantly activated not only the expected “peripheral” retinotopic cortex but also the deprived “foveal” cortex. Crucially, MD6 exhibited no such large-scale reorganization 5 years earlier when she had some foveal sparing. By contrast, in the control participants, stimulation at the matched peripheral location produced significant activation in peripheral retinotopic cortex only. Conclusions: We conclude that complete loss of foveal function may be a necessary condition for large-scale reorganization of visual processing in individuals with MD. National Institutes of Health (U.S.) (Grant EY016559) National Institutes of Health (U.S.) (Grant EY13455) 2016-05-09T16:55:50Z 2016-05-09T16:55:50Z 2014-08 Article http://purl.org/eprint/type/JournalArticle 1040-5488 http://hdl.handle.net/1721.1/102441 Dilks, Daniel D., Joshua B. Julian, Eli Peli, and Nancy Kanwisher. “Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss:” Optometry and Vision Science 91, no. 8 (August 2014): e199–206. https://orcid.org/0000-0003-3853-7885 en_US http://dx.doi.org/10.1097/opx.0000000000000325 Optometry and Vision Science Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Ovid Technologies (Wolters Kluwer) - Lippincott Williams & Wilkins PMC |
| spellingShingle | Dilks, Daniel D. Julian, Joshua B. Peli, Eli Kanwisher, Nancy Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss |
| title | Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss |
| title_full | Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss |
| title_fullStr | Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss |
| title_full_unstemmed | Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss |
| title_short | Reorganization of Visual Processing in Age-Related Macular Degeneration Depends on Foveal Loss |
| title_sort | reorganization of visual processing in age related macular degeneration depends on foveal loss |
| url | http://hdl.handle.net/1721.1/102441 https://orcid.org/0000-0003-3853-7885 |
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