Please use this identifier to cite or link to this item: http://dx.doi.org/10.25673/39752
Title: Modulating the global orientation bias of the visual system changes population receptive field elongations
Author(s): Merkel, Christian
Hopf, Jens-MaxLook up in the Integrated Authority File of the German National Library
Schoenfeld, Mircea ArielLook up in the Integrated Authority File of the German National Library
Issue Date: 2020
Type: Article
Language: English
URN: urn:nbn:de:gbv:ma9:1-1981185920-417073
Subjects: Functional MRI
Orientation adapter
Population receptive fields
Abstract: The topographical structure of the visual system in individual subjects can be visualized using fMRI. Recently, a radial bias for the long axis of population receptive fields (pRF) has been shown using fMRI. It has been theorized that the elongation of receptive fields pointing toward the fovea results from horizontal local connections bundling orientation selective units mostly parallel to their polar position within the visual field. In order to investigate whether there is a causal relationship between orientation selectivity and pRF elongation the current study employed a global orientation adapter to modulate the orientation bias for the visual system while measuring spatial pRF characteristics. The hypothesis was that the orientation tuning change of neural populations would alter pRF elongations toward the fovea particularly at axial positions parallel and orthogonal to the affected orientation. The results indeed show a different amount of elongation of pRF units and their orientation at parallel and orthogonal axial positions relative to the adapter orientation. Within the lower left hemifield, pRF radial bias and elongation showed an increase during adaptation to a 135 grating while both parameters decreased during the presentation of a 45 adapter stimulus. The lower right visual field showed the reverse pattern. No modulation of the pRF topographies were observed in the upper visual field probably due to a vertical visual field asymmetry of sensitivity toward the low contrast spatial frequency pattern of the adapter stimulus. These data suggest a direct relationship between orientation selectivity and elongation of population units within the visual cortex.
URI: https://opendata.uni-halle.de//handle/1981185920/41707
http://dx.doi.org/10.25673/39752
Open Access: Open access publication
License: (CC BY 4.0) Creative Commons Attribution 4.0(CC BY 4.0) Creative Commons Attribution 4.0
Sponsor/Funder: Projekt DEAL 2019
Journal Title: Human brain mapping
Publisher: Wiley-Liss
Publisher Place: New York, NY
Volume: 41
Issue: 7
Original Publication: 10.1002/hbm.24909
Page Start: 1765
Page End: 1774
Appears in Collections:Fakultät für Naturwissenschaften (OA)

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