Human blindsight is mediated by an intact geniculo-extrastriate pathway
Although damage to the primary visual cortex (V1) causes hemianopia, many patients retain some residual vision; known as blindsight. We show that blindsight may be facilitated by an intact white-matter pathway between the lateral geniculate nucleus and motion area hMT+. Visual psychophysics, diffusi...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
eLife Sciences Publications
2015
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| _version_ | 1797107998671241216 |
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| author | Ajina, S Pestilli, F Rokem, A Kennard, C Bridge, H |
| author_facet | Ajina, S Pestilli, F Rokem, A Kennard, C Bridge, H |
| author_sort | Ajina, S |
| collection | OXFORD |
| description | Although damage to the primary visual cortex (V1) causes hemianopia, many patients retain some residual vision; known as blindsight. We show that blindsight may be facilitated by an intact white-matter pathway between the lateral geniculate nucleus and motion area hMT+. Visual psychophysics, diffusion-weighted magnetic resonance imaging and fibre tractography were applied in 17 patients with V1 damage acquired during adulthood and 9 age-matched controls. Individuals with V1 damage were subdivided into blindsight positive (preserved residual vision) and negative (no residual vision) according to psychophysical performance. All blindsight positive individuals showed intact geniculo-hMT+ pathways, while this pathway was significantly impaired or not measurable in blindsight negative individuals. Two white matter pathways previously implicated in blindsight: (i) superior colliculus to hMT+ and (ii) between hMT+ in each hemisphere were not consistently present in blindsight positive cases. Understanding the visual pathways crucial for residual vision may direct future rehabilitation strategies for hemianopia patients. |
| first_indexed | 2024-03-07T07:23:21Z |
| format | Journal article |
| id | oxford-uuid:bd95ff93-f402-431e-b6b0-c588b059feb4 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:23:21Z |
| publishDate | 2015 |
| publisher | eLife Sciences Publications |
| record_format | dspace |
| spelling | oxford-uuid:bd95ff93-f402-431e-b6b0-c588b059feb42022-10-28T11:27:31ZHuman blindsight is mediated by an intact geniculo-extrastriate pathwayJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:bd95ff93-f402-431e-b6b0-c588b059feb4EnglishSymplectic Elements at OxfordeLife Sciences Publications2015Ajina, SPestilli, FRokem, AKennard, CBridge, HAlthough damage to the primary visual cortex (V1) causes hemianopia, many patients retain some residual vision; known as blindsight. We show that blindsight may be facilitated by an intact white-matter pathway between the lateral geniculate nucleus and motion area hMT+. Visual psychophysics, diffusion-weighted magnetic resonance imaging and fibre tractography were applied in 17 patients with V1 damage acquired during adulthood and 9 age-matched controls. Individuals with V1 damage were subdivided into blindsight positive (preserved residual vision) and negative (no residual vision) according to psychophysical performance. All blindsight positive individuals showed intact geniculo-hMT+ pathways, while this pathway was significantly impaired or not measurable in blindsight negative individuals. Two white matter pathways previously implicated in blindsight: (i) superior colliculus to hMT+ and (ii) between hMT+ in each hemisphere were not consistently present in blindsight positive cases. Understanding the visual pathways crucial for residual vision may direct future rehabilitation strategies for hemianopia patients. |
| spellingShingle | Ajina, S Pestilli, F Rokem, A Kennard, C Bridge, H Human blindsight is mediated by an intact geniculo-extrastriate pathway |
| title | Human blindsight is mediated by an intact geniculo-extrastriate pathway |
| title_full | Human blindsight is mediated by an intact geniculo-extrastriate pathway |
| title_fullStr | Human blindsight is mediated by an intact geniculo-extrastriate pathway |
| title_full_unstemmed | Human blindsight is mediated by an intact geniculo-extrastriate pathway |
| title_short | Human blindsight is mediated by an intact geniculo-extrastriate pathway |
| title_sort | human blindsight is mediated by an intact geniculo extrastriate pathway |
| work_keys_str_mv | AT ajinas humanblindsightismediatedbyanintactgeniculoextrastriatepathway AT pestillif humanblindsightismediatedbyanintactgeniculoextrastriatepathway AT rokema humanblindsightismediatedbyanintactgeniculoextrastriatepathway AT kennardc humanblindsightismediatedbyanintactgeniculoextrastriatepathway AT bridgeh humanblindsightismediatedbyanintactgeniculoextrastriatepathway |