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Mapping Visual Field Defects With fMRI – Impact of Approach and Experimental Conditions

Current initiatives to restore vision emphasize the need for objective assessments of visual field (VF) defects as pursued with functional magnetic resonance imaging (fMRI) approaches. Here, we compared population receptive field (pRF) mapping-based VF reconstructions to an fMRI method that uses mor...

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Autores principales: Prabhakaran, Gokulraj T., Al-Nosairy, Khaldoon O., Tempelmann, Claus, Thieme, Hagen, Hoffmann, Michael B.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8455880/
https://www.ncbi.nlm.nih.gov/pubmed/34566575
http://dx.doi.org/10.3389/fnins.2021.745886
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author Prabhakaran, Gokulraj T.
Al-Nosairy, Khaldoon O.
Tempelmann, Claus
Thieme, Hagen
Hoffmann, Michael B.
author_facet Prabhakaran, Gokulraj T.
Al-Nosairy, Khaldoon O.
Tempelmann, Claus
Thieme, Hagen
Hoffmann, Michael B.
author_sort Prabhakaran, Gokulraj T.
collection PubMed
description Current initiatives to restore vision emphasize the need for objective assessments of visual field (VF) defects as pursued with functional magnetic resonance imaging (fMRI) approaches. Here, we compared population receptive field (pRF) mapping-based VF reconstructions to an fMRI method that uses more robust visual stimulation (on-off block design) in combination with individualized anatomy-driven retinotopic atlas-information (atlas-based VF). We investigated participants with sizable peripheral VF-deficits due to advanced glaucoma (n = 4) or retinitis pigmentosa (RP; n = 2) and controls (n = 6) with simulated scotoma. We obtained (1) standard automated perimetry (SAP) data as reference VFs and 3T fMRI data for (2) pRF-mapping [8-direction bar stimulus, fixation color change task] and (3) block-design full-field stimulation [8-direction drifting contrast patterns during (a) passive viewing (PV) and (b) one-back-task (OBT; reporting successions of identical motion directions) to probe the impact of previously reported task-related unspecific visual cortex activations]. Correspondence measures between the SAP and fMRI-based VFs were accuracy, assisted by sensitivity and specificity. We found an accuracy of pRF-based VF from V1 in patients [median: 0.62] that was similar to previous reports and increased by adding V2 and V3 to the analysis [0.74]. In comparison to the pRF-based VF, equivalent accuracies were obtained for the atlas-based VF for both PV [0.67] and, unexpectedly, the OBT [0.59], where, however, unspecific cortical activations were reflected by a reduction in sensitivity [0.71 (PV) and 0.35 (OBT)]. In conclusion, in patients with peripheral VF-defects, we demonstrate that previous fMRI procedures to obtain VF-estimates might be enhanced by: (1) pooling V1-V3 to enhance accuracy; (2) reporting sensitivity and specificity measures to increase transparency of the VF-reconstruction metric; (3) applying atlas-based procedures, if pRF-based VFs are not available or difficult to obtain; and (4) giving, counter-intuitively, preference to PV. These findings are expected to provide guidance to overcome current limitations of translating fMRI-based methods to a clinical work-up.
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spelling pubmed-84558802021-09-23 Mapping Visual Field Defects With fMRI – Impact of Approach and Experimental Conditions Prabhakaran, Gokulraj T. Al-Nosairy, Khaldoon O. Tempelmann, Claus Thieme, Hagen Hoffmann, Michael B. Front Neurosci Neuroscience Current initiatives to restore vision emphasize the need for objective assessments of visual field (VF) defects as pursued with functional magnetic resonance imaging (fMRI) approaches. Here, we compared population receptive field (pRF) mapping-based VF reconstructions to an fMRI method that uses more robust visual stimulation (on-off block design) in combination with individualized anatomy-driven retinotopic atlas-information (atlas-based VF). We investigated participants with sizable peripheral VF-deficits due to advanced glaucoma (n = 4) or retinitis pigmentosa (RP; n = 2) and controls (n = 6) with simulated scotoma. We obtained (1) standard automated perimetry (SAP) data as reference VFs and 3T fMRI data for (2) pRF-mapping [8-direction bar stimulus, fixation color change task] and (3) block-design full-field stimulation [8-direction drifting contrast patterns during (a) passive viewing (PV) and (b) one-back-task (OBT; reporting successions of identical motion directions) to probe the impact of previously reported task-related unspecific visual cortex activations]. Correspondence measures between the SAP and fMRI-based VFs were accuracy, assisted by sensitivity and specificity. We found an accuracy of pRF-based VF from V1 in patients [median: 0.62] that was similar to previous reports and increased by adding V2 and V3 to the analysis [0.74]. In comparison to the pRF-based VF, equivalent accuracies were obtained for the atlas-based VF for both PV [0.67] and, unexpectedly, the OBT [0.59], where, however, unspecific cortical activations were reflected by a reduction in sensitivity [0.71 (PV) and 0.35 (OBT)]. In conclusion, in patients with peripheral VF-defects, we demonstrate that previous fMRI procedures to obtain VF-estimates might be enhanced by: (1) pooling V1-V3 to enhance accuracy; (2) reporting sensitivity and specificity measures to increase transparency of the VF-reconstruction metric; (3) applying atlas-based procedures, if pRF-based VFs are not available or difficult to obtain; and (4) giving, counter-intuitively, preference to PV. These findings are expected to provide guidance to overcome current limitations of translating fMRI-based methods to a clinical work-up. Frontiers Media S.A. 2021-09-08 /pmc/articles/PMC8455880/ /pubmed/34566575 http://dx.doi.org/10.3389/fnins.2021.745886 Text en Copyright © 2021 Prabhakaran, Al-Nosairy, Tempelmann, Thieme and Hoffmann. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Prabhakaran, Gokulraj T.
Al-Nosairy, Khaldoon O.
Tempelmann, Claus
Thieme, Hagen
Hoffmann, Michael B.
Mapping Visual Field Defects With fMRI – Impact of Approach and Experimental Conditions
title Mapping Visual Field Defects With fMRI – Impact of Approach and Experimental Conditions
title_full Mapping Visual Field Defects With fMRI – Impact of Approach and Experimental Conditions
title_fullStr Mapping Visual Field Defects With fMRI – Impact of Approach and Experimental Conditions
title_full_unstemmed Mapping Visual Field Defects With fMRI – Impact of Approach and Experimental Conditions
title_short Mapping Visual Field Defects With fMRI – Impact of Approach and Experimental Conditions
title_sort mapping visual field defects with fmri – impact of approach and experimental conditions
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8455880/
https://www.ncbi.nlm.nih.gov/pubmed/34566575
http://dx.doi.org/10.3389/fnins.2021.745886
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