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Pais ML, Teixeira M, Soares C, Lima G, Rijo P, Cabral C, Castelo-Branco M. Rapid effects of tryptamine psychedelics on perceptual distortions and early visual cortical population receptive fields. Neuroimage 2024; 297:120718. [PMID: 38964563 DOI: 10.1016/j.neuroimage.2024.120718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 06/28/2024] [Accepted: 07/01/2024] [Indexed: 07/06/2024] Open
Abstract
N, N-dimethyltryptamine (DMT) is a psychedelic tryptamine acting on 5-HT2A serotonin receptors, which is associated with intense visual hallucinatory phenomena and perceptual changes such as distortions in visual space. The neural underpinnings of these effects remain unknown. We hypothesised that changes in population receptive field (pRF) properties in the primary visual cortex (V1) might underlie visual perceptual experience. We tested this hypothesis using magnetic resonance imaging (MRI) in a within-subject design. We used a technique called pRF mapping, which measures neural population visual response properties and retinotopic maps in early visual areas. We show that in the presence of visual effects, as documented by the Hallucinogen Rating Scale (HRS), the mean pRF sizes in V1 significantly increase in the peripheral visual field for active condition (inhaled DMT) compared to the control. Eye and head movement differences were absent across conditions. This evidence for short-term effects of DMT in pRF may explain perceptual distortions induced by psychedelics such as field blurring, tunnel vision (peripheral vision becoming blurred while central vision remains sharp) and the enlargement of nearby visual space, particularly at the visual locations surrounding the fovea. Our findings are also consistent with a mechanistic framework whereby gain control of ongoing and evoked activity in the visual cortex is controlled by activation of 5-HT2A receptors.
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Affiliation(s)
- Marta Lapo Pais
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Portugal; Institute of Nuclear Sciences Applied to Health (ICNAS), Portugal
| | - Marta Teixeira
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Portugal; Institute of Nuclear Sciences Applied to Health (ICNAS), Portugal
| | - Carla Soares
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Portugal; Institute of Nuclear Sciences Applied to Health (ICNAS), Portugal
| | - Gisela Lima
- Institute of Nuclear Sciences Applied to Health (ICNAS), Portugal; University of Maastricht, the Netherlands; Faculty of Medicine (FMUC), University of Coimbra, Portugal
| | - Patrícia Rijo
- CBIOS-Universidade Lusófona's Research Center for Biosciences & Health Technologies, Portugal; iMed.ULisboa, Faculty of Pharmacy, University of Lisbon, Portugal
| | - Célia Cabral
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Clinic Academic Center of Coimbra (CACC), University of Coimbra, FMUC, Portugal; Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, Portugal; Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Portugal
| | - Miguel Castelo-Branco
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, Portugal; Institute of Nuclear Sciences Applied to Health (ICNAS), Portugal; University of Maastricht, the Netherlands; Faculty of Medicine (FMUC), University of Coimbra, Portugal.
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2
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Ritter M, Hummer A, Pawloff M, Ledolter AA, Linhardt D, Woletz M, Deak GG, Sacu S, Ristl R, Ramazanova D, Holder GE, Windischberger C, Schmidt-Erfurth UM. Retinotopic cortical mapping in objective functional monitoring of macular therapy. Br J Ophthalmol 2024:bjophthalmol-2021-320723. [PMID: 38811051 DOI: 10.1136/bjo-2021-320723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 05/15/2024] [Indexed: 05/31/2024]
Abstract
BACKGROUND/AIMS To determine the suitability of functional MRI (fMRI) as an objective measure of macular function following therapeutic intervention; conventional psychophysical measures rely heavily on patient compliance. METHODS Twenty patients with neovascular age-related macular degeneration (nAMD) were studied with high-resolution fMRI, visual acuity, reading accuracy and speed, contrast sensitivity (CS) and microperimetry (MP) before and after 3 monthly intravitreal injections of ranibizumab. Population-receptive field retinotopic maps calculated from fMRI data were compared with psychophysical measures and optical coherence tomography. RESULTS Best-corrected visual acuity (BCVA) responders (≥5 letters) showed an increase of 29.5% in activated brain area, while non-responders showed a decrease of 0.8%. Radial histograms over eccentricity allowed quantification of the absolute number of significant voxels and thus differences before and after treatment. Responders showed increases in foveal (α<0.5°) activation, while non-responders did not. Absence of intraretinal fluid and preservation of outer retinal layers was associated with higher numbers of active V1 voxels and better BCVA. Higher voxel numbers were associated with improved reading performance and, less marked, with BCVA, CS and MP. CONCLUSION The data show that retinotopic mapping using fMRI can successfully be applied objectively to evaluate the therapeutic response in nAMD patients treated with anti-vascular endothelial growth factor therapy. This demonstrates the ability of retinotopic mapping to provide an objective assessment of functional recovery at a cortical level; the technique can therefore be applied, in other degenerative macular diseases, to the assessment of potential therapeutic interventions such as gene therapy or cell replacement therapy.
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Affiliation(s)
- Markus Ritter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Allan Hummer
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Maximilian Pawloff
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Anna A Ledolter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - David Linhardt
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Michael Woletz
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Gabor Gyoergy Deak
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Stefan Sacu
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Robin Ristl
- Section for Medical Statistics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Dariga Ramazanova
- Section for Medical Statistics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Graham E Holder
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- UCL Institute of Ophthalmology, London, UK
| | - Christian Windischberger
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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3
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Heitmann C, Zhan M, Linke M, Hölig C, Kekunnaya R, van Hoof R, Goebel R, Röder B. Early visual experience refines the retinotopic organization within and across visual cortical regions. Curr Biol 2023; 33:4950-4959.e4. [PMID: 37918397 DOI: 10.1016/j.cub.2023.10.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 09/29/2023] [Accepted: 10/06/2023] [Indexed: 11/04/2023]
Abstract
Early visual areas are retinotopically organized in human and non-human primates. Population receptive field (pRF) size increases with eccentricity and from lower- to higher-level visual areas. Furthermore, the cortical magnification factor (CMF), a measure of how much cortical space is devoted to each degree of visual angle, is typically larger for foveal as opposed to peripheral regions of the visual field. Whether this fine-scale organization within and across visual areas depends on early visual experience has yet been unknown. Here, we employed 7T functional magnetic resonance imaging pRF mapping to assess the retinotopic organization of early visual regions (i.e., V1, V2, and V3) in eight sight recovery individuals with a history of congenital blindness until a maximum of 4 years of age. Compared with sighted controls, foveal pRF sizes in these individuals were larger, and pRF sizes did not show the typical increase with eccentricity and down the visual cortical processing stream (V1-V2-V3). Cortical magnification was overall diminished and decreased less from foveal to parafoveal visual field locations. Furthermore, cortical magnification correlated with visual acuity in sight recovery individuals. The results of this study suggest that early visual experience is essential for refining a presumably innate prototypical retinotopic organization in humans within and across visual areas, which seems to be crucial for acquiring full visual capabilities.
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Affiliation(s)
- Carolin Heitmann
- Biological Psychology and Neuropsychology Lab, Faculty of Psychology and Movement Sciences, Universität Hamburg, Von-Melle-Park 11, 20146 Hamburg, Germany.
| | - Minye Zhan
- U992 (Cognitive neuroimaging unit), NeuroSpin, INSERM-CEA, 91191 Gif sur Yvette, France
| | - Madita Linke
- Biological Psychology and Neuropsychology Lab, Faculty of Psychology and Movement Sciences, Universität Hamburg, Von-Melle-Park 11, 20146 Hamburg, Germany
| | - Cordula Hölig
- Biological Psychology and Neuropsychology Lab, Faculty of Psychology and Movement Sciences, Universität Hamburg, Von-Melle-Park 11, 20146 Hamburg, Germany
| | - Ramesh Kekunnaya
- U992 (Cognitive neuroimaging unit), NeuroSpin, INSERM-CEA, 91191 Gif sur Yvette, France
| | - Rick van Hoof
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6229 ER Maastricht, the Netherlands
| | - Rainer Goebel
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Universiteitssingel 40, 6229 ER Maastricht, the Netherlands; Department of Development and Research, Brain Innovation B.V., Oxfordlaan 55, 6229 EV Maastricht, the Netherlands
| | - Brigitte Röder
- Biological Psychology and Neuropsychology Lab, Faculty of Psychology and Movement Sciences, Universität Hamburg, Von-Melle-Park 11, 20146 Hamburg, Germany; Child Sight Institute, Jasti V. Ramanamma Children's Eye Care Center, LV Prasad Eye Institute, Hyderabad, Telangana 500034, India.
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4
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Tangtartharakul G, Morgan CA, Rushton SK, Schwarzkopf DS. Retinotopic connectivity maps of human visual cortex with unconstrained eye movements. Hum Brain Mapp 2023; 44:5221-5237. [PMID: 37555758 PMCID: PMC10543111 DOI: 10.1002/hbm.26446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 06/27/2023] [Accepted: 07/26/2023] [Indexed: 08/10/2023] Open
Abstract
Human visual cortex contains topographic visual field maps whose organization can be revealed with retinotopic mapping. Unfortunately, constraints posed by standard mapping hinder its use in patients, atypical subject groups, and individuals at either end of the lifespan. This severely limits the conclusions we can draw about visual processing in such individuals. Here, we present a novel data-driven method to estimate connective fields, resulting in fine-grained maps of the functional connectivity between brain areas. We find that inhibitory connectivity fields accompany, and often surround facilitatory fields. The visual field extent of these inhibitory subfields falls off with cortical magnification. We further show that our method is robust to large eye movements and myopic defocus. Importantly, freed from the controlled stimulus conditions in standard mapping experiments, using entertaining stimuli and unconstrained eye movements our approach can generate retinotopic maps, including the periphery visual field hitherto only possible to map with special stimulus displays. Generally, our results show that the connective field method can gain knowledge about retinotopic architecture of visual cortex in patients and participants where this is at best difficult and confounded, if not impossible, with current methods.
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Affiliation(s)
- Gene Tangtartharakul
- School of Optometry and Vision ScienceUniversity of AucklandAucklandNew Zealand
- School of Psychology and Centre for Brain ResearchUniversity of AucklandAucklandNew Zealand
| | - Catherine A. Morgan
- School of Psychology and Centre for Brain ResearchUniversity of AucklandAucklandNew Zealand
- Centre for Advanced MRIUniServices LimitedAucklandNew Zealand
| | | | - D. Samuel Schwarzkopf
- School of Optometry and Vision ScienceUniversity of AucklandAucklandNew Zealand
- Experimental PsychologyUniversity College LondonLondonUK
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5
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Kupers ER, Edadan A, Benson NC, Zuiderbaan W, de Jong MC, Dumoulin SO, Winawer J. A population receptive field model of the magnetoencephalography response. Neuroimage 2021; 244:118554. [PMID: 34509622 PMCID: PMC8631249 DOI: 10.1016/j.neuroimage.2021.118554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 07/16/2021] [Accepted: 09/02/2021] [Indexed: 12/23/2022] Open
Abstract
Computational models which predict the neurophysiological response from experimental stimuli have played an important role in human neuroimaging. One type of computational model, the population receptive field (pRF), has been used to describe cortical responses at the millimeter scale using functional magnetic resonance imaging (fMRI) and electrocorticography (ECoG). However, pRF models are not widely used for non-invasive electromagnetic field measurements (EEG/MEG), because individual sensors pool responses originating from several centimeter of cortex, containing neural populations with widely varying spatial tuning. Here, we introduce a forward-modeling approach in which pRFs estimated from fMRI data are used to predict MEG sensor responses. Subjects viewed contrast-reversing bar stimuli sweeping across the visual field in separate fMRI and MEG sessions. Individual subject's pRFs were modeled on the cortical surface at the millimeter scale using the fMRI data. We then predicted cortical time series and projected these predictions to MEG sensors using a biophysical MEG forward model, accounting for the pooling across cortex. We compared the predicted MEG responses to observed visually evoked steady-state responses measured in the MEG session. We found that pRF parameters estimated by fMRI could explain a substantial fraction of the variance in steady-state MEG sensor responses (up to 60% in individual sensors). Control analyses in which we artificially perturbed either pRF size or pRF position reduced MEG prediction accuracy, indicating that MEG data are sensitive to pRF properties derived from fMRI. Our model provides a quantitative approach to link fMRI and MEG measurements, thereby enabling advances in our understanding of spatiotemporal dynamics in human visual field maps.
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Affiliation(s)
- Eline R Kupers
- Department of Psychology, New York University, New York, NY 10003, United States; Center for Neural Science, New York University, New York, NY 10003, United States; Department of Psychology, Stanford University, Stanford, CA 94305, United States.
| | - Akhil Edadan
- Spinoza Center for Neuroimaging, Amsterdam 1105 BK, the Netherlands; Department of Experimental Psychology, Utrecht University, Utrecht 3584 CS, the Netherlands
| | - Noah C Benson
- Department of Psychology, New York University, New York, NY 10003, United States; Center for Neural Science, New York University, New York, NY 10003, United States; Sciences Institute, University of Washington, Seattle, WA 98195, United States
| | | | - Maartje C de Jong
- Spinoza Center for Neuroimaging, Amsterdam 1105 BK, the Netherlands; Department of Psychology, University of Amsterdam, Amsterdam 1001 NK, the Netherlands; Amsterdam Brain and Cognition (ABC), University of Amsterdam, Amsterdam 1001 NK, the Netherlands
| | - Serge O Dumoulin
- Spinoza Center for Neuroimaging, Amsterdam 1105 BK, the Netherlands; Department of Experimental Psychology, Utrecht University, Utrecht 3584 CS, the Netherlands; Department of Experimental and Applied Psychology, VU University, Amsterdam 1081 BT, the Netherlands
| | - Jonathan Winawer
- Department of Psychology, New York University, New York, NY 10003, United States; Center for Neural Science, New York University, New York, NY 10003, United States
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6
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Carvalho J, Renken RJ, Cornelissen FW. Predictive masking of an artificial scotoma is associated with a system-wide reconfiguration of neural populations in the human visual cortex. Neuroimage 2021; 245:118690. [PMID: 34758382 DOI: 10.1016/j.neuroimage.2021.118690] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/19/2021] [Accepted: 10/28/2021] [Indexed: 11/29/2022] Open
Abstract
The visual brain has the remarkable capacity to complete our percept of the world even when the information extracted from the visual scene is incomplete. This ability to predict missing information based on information from spatially adjacent regions is an intriguing attribute of healthy vision. Yet, it gains particular significance when it masks the perceptual consequences of a retinal lesion, leaving patients unaware of their partial loss of vision and ultimately delaying diagnosis and treatment. At present, our understanding of the neural basis of this masking process is limited which hinders both quantitative modeling as well as translational application. To overcome this, we asked the participants to view visual stimuli with and without superimposed artificial scotoma (AS). We used fMRI to record the associated cortical activity and applied model-based analyzes to track changes in cortical population receptive fields and connectivity in response to the introduction of the AS. We found that throughout the visual field and cortical hierarchy, pRFs shifted their preferred position towards the AS border. Moreover, extrastriate areas biased their sampling of V1 towards sections outside the AS projection zone, thereby effectively masking the AS with signals from spared portions of the visual field. We speculate that the signals that drive these system-wide population modifications originate in extrastriate visual areas and, through feedback, also reconfigure the neural populations in the earlier visual areas.
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Affiliation(s)
- Joana Carvalho
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Laboratory of Preclinical MRI, Champalimaud Centre for the Unknown, Avenida de Brasília, Lisbon, Portugal 1400-038.
| | - Remco J Renken
- Cognitive Neuroscience Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Frans W Cornelissen
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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7
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Prabhakaran GT, Al-Nosairy KO, Tempelmann C, Thieme H, Hoffmann MB. Mapping Visual Field Defects With fMRI - Impact of Approach and Experimental Conditions. Front Neurosci 2021; 15:745886. [PMID: 34566575 PMCID: PMC8455880 DOI: 10.3389/fnins.2021.745886] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 08/19/2021] [Indexed: 11/13/2022] Open
Abstract
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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Affiliation(s)
| | | | - Claus Tempelmann
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany
| | - Hagen Thieme
- Department of Ophthalmology, Otto von Guericke University, Magdeburg, Germany
| | - Michael B Hoffmann
- Department of Ophthalmology, Otto von Guericke University, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
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8
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Carvalho J, Invernizzi A, Martins J, Jansonius NM, Renken RJ, Cornelissen FW. Visual Field Reconstruction Using fMRI-Based Techniques. Transl Vis Sci Technol 2021; 10:25. [PMID: 33520421 PMCID: PMC7814355 DOI: 10.1167/tvst.10.1.25] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 11/18/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate the accuracy and reliability of functional magnetic resonance imaging (fMRI)-based techniques to assess the integrity of the visual field (VF). Methods We combined 3T fMRI and neurocomputational models, that is, conventional population receptive field (pRF) mapping and a new advanced pRF framework "microprobing" (MP), to reconstruct the VF representations of different cortical areas. To demonstrate their scope, both approaches were applied in healthy participants with simulated scotomas and participants with glaucoma. For the latter group we compared the VFs obtained with standard automated perimetry (SAP) and via fMRI. Results Using SS, we found that the fMRI-based techniques can detect absolute defects in VFs that are larger than 3°, in single participants, based on 12 minutes of fMRI scan time. Moreover, we found that the MP approach results in a less biased estimation of the preserved VF. In participants with glaucoma, we found that fMRI-based VF reconstruction detected VF defects with a correspondence to SAP that was decent, reflected by the positive correlation between fMRI-based sampling density and SAP-based contrast sensitivity loss (SAP) r2 = 0.44, P = 0.0002. This correlation was higher for MP compared to that for the conventional pRF analysis. Conclusions The fMRI-based reconstruction of the VF enables the evaluation of vision loss and provides useful details on the properties of the visual cortex. Translational Relevance The fMRI-based VF reconstruction provides an objective alternative to detect VF defects. It may either complement SAP or could provide VF information in patients unable to perform SAP.
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Affiliation(s)
- Joana Carvalho
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Azzurra Invernizzi
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Joana Martins
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Nomdo M. Jansonius
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Remco J. Renken
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, The Netherlands
- Cognitive Neuroscience Center, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Frans W. Cornelissen
- Laboratory of Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, The Netherlands
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9
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Studying Cortical Plasticity in Ophthalmic and Neurological Disorders: From Stimulus-Driven to Cortical Circuitry Modeling Approaches. Neural Plast 2019; 2019:2724101. [PMID: 31814821 PMCID: PMC6877932 DOI: 10.1155/2019/2724101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/05/2019] [Indexed: 12/30/2022] Open
Abstract
Unsolved questions in computational visual neuroscience research are whether and how neurons and their connecting cortical networks can adapt when normal vision is compromised by a neurodevelopmental disorder or damage to the visual system. This question on neuroplasticity is particularly relevant in the context of rehabilitation therapies that attempt to overcome limitations or damage, through either perceptual training or retinal and cortical implants. Studies on cortical neuroplasticity have generally made the assumption that neuronal population properties and the resulting visual field maps are stable in healthy observers. Consequently, differences in the estimates of these properties between patients and healthy observers have been taken as a straightforward indication for neuroplasticity. However, recent studies imply that the modeled neuronal properties and the cortical visual maps vary substantially within healthy participants, e.g., in response to specific stimuli or under the influence of cognitive factors such as attention. Although notable advances have been made to improve the reliability of stimulus-driven approaches, the reliance on the visual input remains a challenge for the interpretability of the obtained results. Therefore, we argue that there is an important role in the study of cortical neuroplasticity for approaches that assess intracortical signal processing and circuitry models that can link visual cortex anatomy, function, and dynamics.
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10
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Senden M, Emmerling TC, van Hoof R, Frost MA, Goebel R. Reconstructing imagined letters from early visual cortex reveals tight topographic correspondence between visual mental imagery and perception. Brain Struct Funct 2019; 224:1167-1183. [PMID: 30637491 PMCID: PMC6499877 DOI: 10.1007/s00429-019-01828-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 01/05/2019] [Indexed: 11/12/2022]
Abstract
Visual mental imagery is the quasi-perceptual experience of “seeing in the mind’s eye”. While a tight correspondence between imagery and perception in terms of subjective experience is well established, their correspondence in terms of neural representations remains insufficiently understood. In the present study, we exploit the high spatial resolution of functional magnetic resonance imaging (fMRI) at 7T, the retinotopic organization of early visual cortex, and machine-learning techniques to investigate whether visual imagery of letter shapes preserves the topographic organization of perceived shapes. Sub-millimeter resolution fMRI images were obtained from early visual cortex in six subjects performing visual imagery of four different letter shapes. Predictions of imagery voxel activation patterns based on a population receptive field-encoding model and physical letter stimuli provided first evidence in favor of detailed topographic organization. Subsequent visual field reconstructions of imagery data based on the inversion of the encoding model further showed that visual imagery preserves the geometric profile of letter shapes. These results open new avenues for decoding, as we show that a denoising autoencoder can be used to pretrain a classifier purely based on perceptual data before fine-tuning it on imagery data. Finally, we show that the autoencoder can project imagery-related voxel activations onto their perceptual counterpart allowing for visually recognizable reconstructions even at the single-trial level. The latter may eventually be utilized for the development of content-based BCI letter-speller systems.
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Affiliation(s)
- Mario Senden
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6201 BC, Maastricht, The Netherlands. .,Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre, Faculty of Psychology and Neuroscience, Maastricht University, Oxfordlaan 55, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
| | - Thomas C Emmerling
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6201 BC, Maastricht, The Netherlands.,Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre, Faculty of Psychology and Neuroscience, Maastricht University, Oxfordlaan 55, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Rick van Hoof
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6201 BC, Maastricht, The Netherlands.,Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre, Faculty of Psychology and Neuroscience, Maastricht University, Oxfordlaan 55, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Martin A Frost
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6201 BC, Maastricht, The Netherlands.,Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre, Faculty of Psychology and Neuroscience, Maastricht University, Oxfordlaan 55, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Rainer Goebel
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, 6201 BC, Maastricht, The Netherlands.,Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre, Faculty of Psychology and Neuroscience, Maastricht University, Oxfordlaan 55, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.,Department of Neuroimaging and Neuromodeling, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA, Amsterdam, The Netherlands
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11
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van Es DM, Theeuwes J, Knapen T. Spatial sampling in human visual cortex is modulated by both spatial and feature-based attention. eLife 2018; 7:e36928. [PMID: 30526848 PMCID: PMC6286128 DOI: 10.7554/elife.36928] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 11/13/2018] [Indexed: 11/13/2022] Open
Abstract
Spatial attention changes the sampling of visual space. Behavioral studies suggest that feature-based attention modulates this resampling to optimize the attended feature's sampling. We investigate this hypothesis by estimating spatial sampling in visual cortex while independently varying both feature-based and spatial attention. Our results show that spatial and feature-based attention interacted: resampling of visual space depended on both the attended location and feature (color vs. temporal frequency). This interaction occurred similarly throughout visual cortex, regardless of an area's overall feature preference. However, the interaction did depend on spatial sampling properties of voxels that prefer the attended feature. These findings are parsimoniously explained by variations in the precision of an attentional gain field. Our results demonstrate that the deployment of spatial attention is tailored to the spatial sampling properties of units that are sensitive to the attended feature.
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Affiliation(s)
- Daniel Marten van Es
- Behavioural and Movement SciencesVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Jan Theeuwes
- Behavioural and Movement SciencesVrije Universiteit AmsterdamAmsterdamThe Netherlands
| | - Tomas Knapen
- Behavioural and Movement SciencesVrije Universiteit AmsterdamAmsterdamThe Netherlands
- Spinoza Centre for NeuroimagingRoyal Academy of SciencesAmsterdamThe Netherlands
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12
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Frass-Kriegl R, Navarro de Lara LI, Pichler M, Sieg J, Moser E, Windischberger C, Laistler E. Flexible 23-channel coil array for high-resolution magnetic resonance imaging at 3 Tesla. PLoS One 2018; 13:e0206963. [PMID: 30383832 PMCID: PMC6211745 DOI: 10.1371/journal.pone.0206963] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 10/23/2018] [Indexed: 11/18/2022] Open
Abstract
PURPOSE The purpose of this work is the design, implementation and evaluation of a mechanically flexible receive-only coil array for magnetic resonance imaging (MRI) at 3 T that can be applied to various target organs and provides high parallel imaging performance. METHODS A 23-channel array was designed based on a rigid-flex printed circuit board (PCB). The flexible multi-layer part contains the copper traces forming the coil elements. The rigid part of the PCB houses the solder joints and lumped elements. The coil housing consists of rigid caps mounted above the rigid parts. Adhesive PTFE sheets cover all flexible parts. The developed array was tested on the bench as well as in phantom and in vivo MRI experiments employing parallel imaging acceleration factors up to six. RESULTS Efficient mutual decoupling between receive elements and detuning between receive array and body coil was achieved. An increased signal-to-noise ratio in comparison to commercial reference coils is demonstrated, especially in regions close to the developed array and for high parallel imaging acceleration factors. Exemplary in vivo images of head, ankle, knee, shoulder and hand are presented. CONCLUSION Based on high sensitivity close to the array and low g-factors, this flexible coil is well suited for studies of occipital and temporal cortex, as well as musculoskeletal targets like knee, ankle, elbow and wrist.
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Affiliation(s)
- Roberta Frass-Kriegl
- Division MR Physics, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Lucia Isabel Navarro de Lara
- Division MR Physics, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Michael Pichler
- Division MR Physics, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Jürgen Sieg
- Division MR Physics, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Ewald Moser
- Division MR Physics, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Christian Windischberger
- Division MR Physics, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Elmar Laistler
- Division MR Physics, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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13
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Dumoulin SO, Knapen T. How Visual Cortical Organization Is Altered by Ophthalmologic and Neurologic Disorders. Annu Rev Vis Sci 2018; 4:357-379. [DOI: 10.1146/annurev-vision-091517-033948] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Receptive fields are a core property of cortical organization. Modern neuroimaging allows routine access to visual population receptive fields (pRFs), enabling investigations of clinical disorders. Yet how the underlying neural circuitry operates is controversial. The controversy surrounds observations that measurements of pRFs can change in healthy adults as well as in patients with a range of ophthalmological and neurological disorders. The debate relates to the balance between plasticity and stability of the underlying neural circuitry. We propose that to move the debate forward, the field needs to define the implied mechanism. First, we review the pRF changes in both healthy subjects and those with clinical disorders. Then, we propose a computational model that describes how pRFs can change in healthy humans. We assert that we can correctly interpret the pRF changes in clinical disorders only if we establish the capabilities and limitations of pRF dynamics in healthy humans with mechanistic models that provide quantitative predictions.
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Affiliation(s)
- Serge O. Dumoulin
- Spinoza Centre for Neuroimaging, 1105 BK Amsterdam, Netherlands
- Department of Experimental and Applied Psychology, VU University Amsterdam, 1181 BT Amsterdam, Netherlands
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, 3584 CS Utrecht, Netherlands
| | - Tomas Knapen
- Spinoza Centre for Neuroimaging, 1105 BK Amsterdam, Netherlands
- Department of Experimental and Applied Psychology, VU University Amsterdam, 1181 BT Amsterdam, Netherlands
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14
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Ritter M, Hummer A, Ledolter AA, Holder GE, Windischberger C, Schmidt-Erfurth UM. Correspondence between retinotopic cortical mapping and conventional functional and morphological assessment of retinal disease. Br J Ophthalmol 2018; 103:208-215. [PMID: 29699983 DOI: 10.1136/bjophthalmol-2017-311443] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 04/12/2018] [Indexed: 11/04/2022]
Abstract
PURPOSE The present study describes retinotopic mapping of the primary visual cortex using functional MRI (fMRI) in patients with retinal disease. It addresses the relationship between fMRI data and data obtained by conventional assessment including microperimetry (MP) and structural imaging. METHODS Initial testing involved eight patients with central retinal disease (Stargardt disease, STGD) and eight with peripheral retinal disease (retinitis pigmentosa, RP), who were examined using fMRI and MP (Nidek MP-1). All had a secure clinical diagnosis supported by electrophysiological data. fMRI used population-receptive field (pRF) mapping to provide retinotopic data that were then compared with the results of MP, optical coherence tomography and fundus autofluorescence imaging. RESULTS Full analysis, following assessment of fMRI data reliability criteria, was performed in five patients with STGD and seven patients with RP; unstable fixation was responsible for unreliable pRF measurements in three patients excluded from final analysis. The macular regions in patients with STGD with central visual field defects and outer retinal atrophy (ORA) at the macula correlated well with pRF coverage maps showing reduced density of activated voxels at the occipital pole. Patients with RP exhibited peripheral ORA and concentric visual field defects both on MP and pRF mapping. Anterior V1 voxels, corresponding to peripheral regions, showed no significant activation. Correspondence between MP and pRF mapping was quantified by calculating the simple matching coefficient. CONCLUSION Retinotopic maps acquired by fMRI provide a valuable adjunct in the assessment of retinal dysfunction. The addition of microperimetric data to pRF maps allowed better assessment of macular function than MP alone. Unlike MP, pRF mapping provides objective data independent of psychophysical perception from the patient.
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Affiliation(s)
- Markus Ritter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Allan Hummer
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Anna A Ledolter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Graham E Holder
- Department of Ophthalmology, National University of Singapore, National University Hospital, Singapore.,UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital, London, UK
| | - Christian Windischberger
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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15
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Development differentially sculpts receptive fields across early and high-level human visual cortex. Nat Commun 2018; 9:788. [PMID: 29476135 PMCID: PMC5824941 DOI: 10.1038/s41467-018-03166-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/23/2018] [Indexed: 11/22/2022] Open
Abstract
Receptive fields (RFs) processing information in restricted parts of the visual field are a key property of visual system neurons. However, how RFs develop in humans is unknown. Using fMRI and population receptive field (pRF) modeling in children and adults, we determine where and how pRFs develop across the ventral visual stream. Here we report that pRF properties in visual field maps, from the first visual area, V1, through the first ventro-occipital area, VO1, are adult-like by age 5. However, pRF properties in face-selective and character-selective regions develop into adulthood, increasing the foveal coverage bias for faces in the right hemisphere and words in the left hemisphere. Eye-tracking indicates that pRF changes are related to changing fixation patterns on words and faces across development. These findings suggest a link between face and word viewing behavior and the differential development of pRFs across visual cortex, potentially due to competition on foveal coverage. Population receptive fields (pRFs) in the visual system are key information-processors, but how they develop is unknown. Here, authors use fMRI and pRF modeling in children and adults to show that in the ventral stream only pRFs in face- and word-selective regions continue to develop, mirroring changes in viewing behavior.
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16
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Hummer A, Ritter M, Woletz M, Ledolter AA, Tik M, Dumoulin SO, Holder GE, Schmidt-Erfurth U, Windischberger C. Artificial scotoma estimation based on population receptive field mapping. Neuroimage 2017; 169:342-351. [PMID: 29253656 DOI: 10.1016/j.neuroimage.2017.12.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 11/22/2017] [Accepted: 12/04/2017] [Indexed: 10/18/2022] Open
Abstract
Population receptive field (pRF) mapping based on functional magnetic resonance imaging (fMRI) is an ideal method for obtaining detailed retinotopic information. One particularly promising application of pRF mapping is the estimation and quantification of visual field effects, for example scotomata in patients suffering from macular dysfunction or degeneration (MD) or hemianopic defects in patients with intracranial dysfunction. However, pRF mapping performance is influenced by a number of factors including spatial and temporal resolution, distribution of dural venous sinuses and patient performance. This study addresses the ability of current pRF methodology to assess the size of simulated scotomata in healthy individuals. The data demonstrate that central scotomata down to a radius of 2.35° (4.7° diameter) visual angle can be reliably estimated in single subjects using high spatial resolution protocols and multi-channel receive array coils.
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Affiliation(s)
- A Hummer
- MR Centre of Excellence, Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - M Ritter
- Department of Ophthalmology and Optometry, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - M Woletz
- MR Centre of Excellence, Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - A A Ledolter
- Department of Ophthalmology and Optometry, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - M Tik
- MR Centre of Excellence, Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - S O Dumoulin
- Spinoza Centre for Neuroimaging, Royal Netherlands Academy of Sciences, Meibergdreef 75, 110BK Amsterdam, Netherlands
| | - G E Holder
- Department of Ophthalmology, National University of Singapore & National University Hospital, 1E Kent Ridge Road, Singapore 119228, Singapore; UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK
| | - U Schmidt-Erfurth
- Department of Ophthalmology and Optometry, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - C Windischberger
- MR Centre of Excellence, Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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Image identification from brain activity using the population receptive field model. PLoS One 2017; 12:e0183295. [PMID: 28922355 PMCID: PMC5603170 DOI: 10.1371/journal.pone.0183295] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 08/02/2017] [Indexed: 11/19/2022] Open
Abstract
A goal of computational models is not only to explain experimental data but also to make new predictions. A current focus of computational neuroimaging is to predict features of the presented stimulus from measured brain signals. These computational neuroimaging approaches may be agnostic about the underlying neural processes or may be biologically inspired. Here, we use the biologically inspired population receptive field (pRF) approach to identify presented images from fMRI recordings of the visual cortex, using an explicit model of the underlying neural response selectivity. The advantage of the pRF-model is its simplicity: it is defined by a handful of parameters, which can be estimated from fMRI data that was collected within half an hour. Using 7T MRI, we measured responses elicited by different visual stimuli: (i) conventional pRF mapping stimuli, (ii) semi-random synthetic images and (iii) natural images. The pRF mapping stimuli were used to estimate the pRF-properties of each cortical location in early visual cortex. Next, we used these pRFs to identify which synthetic or natural images was presented to the subject from the fMRI responses. We show that image identification using V1 responses is far above chance, both for the synthetic and natural images. Thus, we can identify visual images, including natural images, using the most fundamental low-parameter pRF model estimated from conventional pRF mapping stimuli. This allows broader application of image identification.
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