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Population receptive field analysis of the primary visual cortex complements perimetry in patients with homonymous visual field defects.

ΤίτλοςPopulation receptive field analysis of the primary visual cortex complements perimetry in patients with homonymous visual field defects.
Publication TypeJournal Article
Year of Publication2014
AuthorsPapanikolaou, A., Keliris G. A., T Papageorgiou D., Shao Y., Krapp E., Papageorgiou E., Stingl K., Bruckmann A., Schiefer U., Logothetis N. K., & Smirnakis S. M.
JournalProc Natl Acad Sci U S A
Volume111
Issue16
PaginationE1656-65
Date Published2014 Apr 22
ISSN1091-6490
Λέξεις κλειδιάBlindness, Brain Mapping, Humans, Retina, Scotoma, Visual Cortex, Visual Field Tests, Visual Fields
Abstract

Injury to the primary visual cortex (V1) typically leads to loss of conscious vision in the corresponding, homonymous region of the contralateral visual hemifield (scotoma). Several studies suggest that V1 is highly plastic after injury to the visual pathways, whereas others have called this conclusion into question. We used functional magnetic resonance imaging (fMRI) to measure area V1 population receptive field (pRF) properties in five patients with partial or complete quadrantic visual field loss as a result of partial V1+ or optic radiation lesions. Comparisons were made with healthy controls deprived of visual stimulation in one quadrant ["artificial scotoma" (AS)]. We observed no large-scale changes in spared-V1 topography as the V1/V2 border remained stable, and pRF eccentricity versus cortical-distance plots were similar to those of controls. Interestingly, three observations suggest limited reorganization: (i) the distribution of pRF centers in spared-V1 was shifted slightly toward the scotoma border in 2 of 5 patients compared with AS controls; (ii) pRF size in spared-V1 was slightly increased in patients near the scotoma border; and (iii) pRF size in the contralesional hemisphere was slightly increased compared with AS controls. Importantly, pRF measurements yield information about the functional properties of spared-V1 cortex not provided by standard perimetry mapping. In three patients, spared-V1 pRF maps overlapped significantly with dense regions of the perimetric scotoma, suggesting that pRF analysis may help identify visual field locations amenable to rehabilitation. Conversely, in the remaining two patients, spared-V1 pRF maps failed to cover sighted locations in the perimetric map, indicating the existence of V1-bypassing pathways able to mediate useful vision.

DOI10.1073/pnas.1317074111
Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID24706881
PubMed Central IDPMC4000790
Grant ListR01 EY019272 / EY / NEI NIH HHS / United States
R01 EY024019 / EY / NEI NIH HHS / United States
R01 EY024019 / EY / NEI NIH HHS / United States
/ / Howard Hughes Medical Institute / United States

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