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Ofir‐Geva S, Meilijson I, Frenkel‐Toledo S, Soroker N. Use of multi-perturbation Shapley analysis in lesion studies of functional networks: The case of upper limb paresis. Hum Brain Mapp 2023; 44:1320-1343. [PMID: 36206326 PMCID: PMC9921264 DOI: 10.1002/hbm.26105] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 09/07/2022] [Accepted: 09/19/2022] [Indexed: 11/07/2022] Open
Abstract
Understanding the impact of variation in lesion topography on the expression of functional impairments following stroke is important, as it may pave the way to modeling structure-function relations in statistical terms while pointing to constraints for adaptive remapping and functional recovery. Multi-perturbation Shapley-value analysis (MSA) is a relatively novel game-theoretical approach for multivariate lesion-symptom mapping. In this methodological paper, we provide a comprehensive explanation of MSA. We use synthetic data to assess the method's accuracy and perform parameter optimization. We then demonstrate its application using a cohort of 107 first-event subacute stroke patients, assessed for upper limb (UL) motor impairment (Fugl-Meyer Assessment scale). Under the conditions tested, MSA could correctly detect simulated ground-truth lesion-symptom relationships with a sensitivity of 75% and specificity of ~90%. For real behavioral data, MSA disclosed a strong hemispheric effect in the relative contribution of specific regions-of-interest (ROIs): poststroke UL motor function was mostly contributed by damage to ROIs associated with movement planning (supplementary motor cortex and superior frontal gyrus) following left-hemispheric damage (LHD) and by ROIs associated with movement execution (primary motor and somatosensory cortices and the ventral brainstem) following right-hemispheric damage (RHD). Residual UL motor ability following LHD was found to depend on a wider array of brain structures compared to the residual motor ability of RHD patients. The results demonstrate that MSA can provide a unique insight into the relative importance of different hubs in neural networks, which is difficult to obtain using standard univariate methods.
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Affiliation(s)
- Shay Ofir‐Geva
- Department of Neurological RehabilitationLoewenstein Rehabilitation Medical CenterRaananaIsrael
- Department of Rehabilitation Medicine, Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Isaac Meilijson
- School of Mathematical SciencesTel Aviv UniversityTel AvivIsrael
| | | | - Nachum Soroker
- Department of Neurological RehabilitationLoewenstein Rehabilitation Medical CenterRaananaIsrael
- Department of Rehabilitation Medicine, Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
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Masina F, Pezzetta R, Lago S, Mantini D, Scarpazza C, Arcara G. Disconnection from prediction: A systematic review on the role of right temporoparietal junction in aberrant predictive processing. Neurosci Biobehav Rev 2022; 138:104713. [PMID: 35636560 DOI: 10.1016/j.neubiorev.2022.104713] [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: 01/21/2022] [Revised: 05/06/2022] [Accepted: 05/24/2022] [Indexed: 11/27/2022]
Abstract
The right temporoparietal junction (rTPJ) is a brain area that plays a critical role in a variety of cognitive functions. Although different theoretical proposals tried to explain the ubiquitous role of rTPJ, recent evidence suggests that rTPJ may be a fundamental cortical region involved in different kinds of predictions. This systematic review aims to better investigate the potential role of rTPJ under a predictive processing perspective, providing an overview of cognitive impairments in neurological patients as the consequence of structural or functional disconnections or damage of rTPJ. Results confirm the involvement of rTPJ across several tasks and neurological pathologies. RTPJ, via its connections with other brain networks, would integrate diverse information and update internal models of the world. Against traditional views, which tend to focus on distinct domains, we argue that the role of rTPJ can be parsimoniously interpreted as a key hub involved in domain-general predictions. This alternative account of rTPJ role in aberrant predictive processing opens different perspectives, stimulating new hypotheses in basic research and clinical contexts.
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Affiliation(s)
| | | | - Sara Lago
- IRCCS San Camillo Hospital, Venice, Italy.
| | - Dante Mantini
- Research Center for Motor Control and Neuroplasticity, KU Leuven, Leuven 3001, Belgium.
| | - Cristina Scarpazza
- IRCCS San Camillo Hospital, Venice, Italy; Department of General Psychology, University of Padua, Padua, Italy.
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Disconnection somewhere down the line: Multivariate lesion-symptom mapping of the line bisection error. Cortex 2020; 133:120-132. [PMID: 33120190 DOI: 10.1016/j.cortex.2020.09.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/17/2020] [Accepted: 09/04/2020] [Indexed: 11/23/2022]
Abstract
Line Bisection is a simple task frequently used in stroke patients to diagnose disorders of spatial perception characterized by a directional bisection bias to the ipsilesional side. However, previous anatomical and behavioural findings are contradictory, and the diagnostic validity of the line bisection task has been challenged. We hereby aimed to re-analyse the anatomical basis of pathological line bisection by using multivariate lesion-symptom mapping and disconnection-symptom mapping based on support vector regression in a sample of 163 right hemispheric acute stroke patients. In line with some previous studies, we observed that pathological line bisection was related to more than a single focal lesion location. Cortical damage primarily to right parietal areas, particularly the inferior parietal lobe, including the angular gyrus, as well as damage to the right basal ganglia contributed to the pathology. In contrast to some previous studies, an involvement of frontal cortical brain areas in the line bisection task was not observed. Subcortically, damage to the right superior longitudinal fasciculus (I, II and III) and arcuate fasciculus as well as the internal capsule was associated with line bisection errors. Moreover, white matter damage of interhemispheric fibre bundles, such as the anterior commissure and posterior parts of the corpus callosum projecting into the left hemisphere, was predictive of pathological deviation in the line bisection task.
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Toba MN, Zavaglia M, Malherbe C, Moreau T, Rastelli F, Kaglik A, Valabrègue R, Pradat-Diehl P, Hilgetag CC, Valero-Cabré A. Game theoretical mapping of white matter contributions to visuospatial attention in stroke patients with hemineglect. Hum Brain Mapp 2020; 41:2926-2950. [PMID: 32243676 PMCID: PMC7336155 DOI: 10.1002/hbm.24987] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 02/24/2020] [Accepted: 03/06/2020] [Indexed: 01/19/2023] Open
Abstract
White matter bundles linking gray matter nodes are key anatomical players to fully characterize associations between brain systems and cognitive functions. Here we used a multivariate lesion inference approach grounded in coalitional game theory (multiperturbation Shapley value analysis, MSA) to infer causal contributions of white matter bundles to visuospatial orienting of attention. Our work is based on the characterization of the lesion patterns of 25 right hemisphere stroke patients and the causal analysis of their impact on three neuropsychological tasks: line bisection, letter cancellation, and bells cancellation. We report that, out of the 11 white matter bundles included in our MSA coalitions, the optic radiations, the inferior fronto-occipital fasciculus and the anterior cingulum were the only tracts to display task-invariant contributions (positive, positive, and negative, respectively) to the tasks. We also report task-dependent influences for the branches of the superior longitudinal fasciculus and the posterior cingulum. By extending prior findings to white matter tracts linking key gray matter nodes, we further characterize from a network perspective the anatomical basis of visual and attentional orienting processes. The knowledge about interactions patterns mediated by white matter tracts linking cortical nodes of attention orienting networks, consolidated by further studies, may help develop and customize brain stimulation approaches for the rehabilitation of visuospatial neglect.
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Affiliation(s)
- Monica N Toba
- Cerebral Dynamics, Plasticity and Rehabilitation Team, Frontlab, Paris Brain Institute, ICM, Sorbonne Universités, UPMC Paris 06, Inserm UMR S 1127, CNRS UMR 7225, F-75013, & IHU-A-ICM, Paris, France.,Institute of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,AP-HP, HxU Pitié-Salpêtrière-Charles-Foix, service de Médecine Physique et de Réadaptation & PHRC Régional NEGLECT, Paris, France.,Laboratory of Functional Neurosciences (EA 4559), University of Picardie Jules Verne, Amiens, France
| | - Melissa Zavaglia
- Institute of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Jacobs University, Focus Area Health, Bremen, Germany
| | - Caroline Malherbe
- Institute of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Neurology, Head and Neuro Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tristan Moreau
- Cerebral Dynamics, Plasticity and Rehabilitation Team, Frontlab, Paris Brain Institute, ICM, Sorbonne Universités, UPMC Paris 06, Inserm UMR S 1127, CNRS UMR 7225, F-75013, & IHU-A-ICM, Paris, France
| | - Federica Rastelli
- Cerebral Dynamics, Plasticity and Rehabilitation Team, Frontlab, Paris Brain Institute, ICM, Sorbonne Universités, UPMC Paris 06, Inserm UMR S 1127, CNRS UMR 7225, F-75013, & IHU-A-ICM, Paris, France.,AP-HP, HxU Pitié-Salpêtrière-Charles-Foix, service de Médecine Physique et de Réadaptation & PHRC Régional NEGLECT, Paris, France
| | - Anna Kaglik
- Cerebral Dynamics, Plasticity and Rehabilitation Team, Frontlab, Paris Brain Institute, ICM, Sorbonne Universités, UPMC Paris 06, Inserm UMR S 1127, CNRS UMR 7225, F-75013, & IHU-A-ICM, Paris, France.,AP-HP, HxU Pitié-Salpêtrière-Charles-Foix, service de Médecine Physique et de Réadaptation & PHRC Régional NEGLECT, Paris, France
| | - Romain Valabrègue
- Centre for NeuroImaging Research-CENIR, Paris Brain Institute, ICM, Sorbonne Universités, Inserm UMR S 1127, CNRS UMR 7225, F-75013, Paris, France
| | - Pascale Pradat-Diehl
- AP-HP, HxU Pitié-Salpêtrière-Charles-Foix, service de Médecine Physique et de Réadaptation & PHRC Régional NEGLECT, Paris, France.,GRC-UPMC n° 18-Handicap cognitif et réadaptation, Paris, France
| | - Claus C Hilgetag
- Institute of Computational Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Health Sciences, Boston University, 635 Commonwealth Ave., Boston, Massachusetts, 02215, USA
| | - Antoni Valero-Cabré
- Cerebral Dynamics, Plasticity and Rehabilitation Team, Frontlab, Paris Brain Institute, ICM, Sorbonne Universités, UPMC Paris 06, Inserm UMR S 1127, CNRS UMR 7225, F-75013, & IHU-A-ICM, Paris, France.,AP-HP, HxU Pitié-Salpêtrière-Charles-Foix, service de Médecine Physique et de Réadaptation & PHRC Régional NEGLECT, Paris, France.,Laboratory for Cerebral Dynamics, Plasticity & Rehabilitation, Boston University School of Medicine, Boston, Massachusetts, 02118, USA
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Neural correlates of visuospatial bias in patients with left hemisphere stroke: a causal functional contribution analysis based on game theory. Neuropsychologia 2018; 115:142-153. [DOI: 10.1016/j.neuropsychologia.2017.10.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 10/10/2017] [Accepted: 10/10/2017] [Indexed: 11/22/2022]
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Toba MN, Zavaglia M, Rastelli F, Valabrégue R, Pradat‐Diehl P, Valero‐Cabré A, Hilgetag CC. Game theoretical mapping of causal interactions underlying visuo-spatial attention in the human brain based on stroke lesions. Hum Brain Mapp 2017; 38:3454-3471. [PMID: 28419682 PMCID: PMC5645205 DOI: 10.1002/hbm.23601] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 03/22/2017] [Accepted: 03/23/2017] [Indexed: 01/08/2023] Open
Abstract
Anatomical studies conducted in neurological conditions have developed our understanding of the causal relationships between brain lesions and their clinical consequences. The analysis of lesion patterns extended across brain networks has been particularly useful in offering new insights on brain-behavior relationships. Here we applied multiperturbation Shapley value Analysis (MSA), a multivariate method based on coalitional game theory inferring causal regional contributions to specific behavioral outcomes from the characteristic functional deficits after stroke lesions. We established the causal patterns of contributions and interactions of nodes of the attentional orienting network on the basis of lesion and behavioral data from 25 right hemisphere stroke patients tested in visuo-spatial attention tasks. We calculated the percentage of damaged voxels for five right hemisphere cortical regions contributing to attentional orienting, involving seven specific Brodmann Areas (BA): Frontal Eye Fields, (FEF-BA6), Intraparietal Sulcus (IPS-BA7), Inferior Frontal Gyrus (IFG-BA44/BA45), Temporo-Parietal Junction (TPJ-BA39/BA40), and Inferior Occipital Gyrus (IOG-BA19). We computed the MSA contributions of these seven BAs to three behavioral clinical tests (line bisection, bells cancellation, and letter cancelation). Our analyses indicated IPS as the main contributor to the attentional orienting and also revealed synergistic influences among IPS, TPJ, and IOG (for bells cancellation and line bisection) and between TPJ and IFG (for bells and letter cancellation tasks). The findings demonstrate the ability of the MSA approach to infer plausible causal contributions of relevant right hemisphere sites in poststroke visuo-spatial attention and awareness disorders. Hum Brain Mapp 38:3454-3471, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Monica N. Toba
- Cerebral Dynamics, Plasticity and Rehabilitation Team, Frontlab, Brain and Spine Institute, ICMParisFrance
- Sorbonne Universités, UPMC Paris 06, Inserm UMR S 1127, CNRS UMR 7225, F‐75013, & IHU‐A‐ICMParisFrance
- Laboratory of Functional Neurosciences (EA 4559)University Hospital of Amiens and University of Picardy Jules VerneAmiensFrance
| | - Melissa Zavaglia
- Department of Computational NeuroscienceUniversity Medical Center Hamburg‐EppendorfHamburgGermany
- School of Engineering and ScienceJacobs University BremenGermany
| | - Federica Rastelli
- Cerebral Dynamics, Plasticity and Rehabilitation Team, Frontlab, Brain and Spine Institute, ICMParisFrance
- Sorbonne Universités, UPMC Paris 06, Inserm UMR S 1127, CNRS UMR 7225, F‐75013, & IHU‐A‐ICMParisFrance
- AP‐HP, HxU Pitié‐Salpêtrière‐Charles‐Foix, service de Médecine Physique et de Réadaptation & PHRC Regional NEGLECTParisFrance
| | - Romain Valabrégue
- Sorbonne Universités, UPMC Paris 06, Inserm UMR S 1127, CNRS UMR 7225, F‐75013, & IHU‐A‐ICMParisFrance
- Centre for NeuroImaging Research ‐ CENIR, Brain and Spine Institute, ICM, Paris, France
| | - Pascale Pradat‐Diehl
- AP‐HP, HxU Pitié‐Salpêtrière‐Charles‐Foix, service de Médecine Physique et de Réadaptation & PHRC Regional NEGLECTParisFrance
- GRC‐UPMC n° 18‐ Handicap cognitif et réadaptationParisFrance
| | - Antoni Valero‐Cabré
- Cerebral Dynamics, Plasticity and Rehabilitation Team, Frontlab, Brain and Spine Institute, ICMParisFrance
- Sorbonne Universités, UPMC Paris 06, Inserm UMR S 1127, CNRS UMR 7225, F‐75013, & IHU‐A‐ICMParisFrance
- Laboratory for Cerebral Dynamics, Plasticity & Rehabilitation, Boston University School of MedicineBostonMassachusetts
- Cognitive Neuroscience and Information Technology Research Program, Open University of Catalonia (UOC)Barcelona08035Spain
| | - Claus C. Hilgetag
- Department of Computational NeuroscienceUniversity Medical Center Hamburg‐EppendorfHamburgGermany
- Department of Health SciencesBoston UniversityBostonMassachusetts
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Zavaglia M, Forkert ND, Cheng B, Gerloff C, Thomalla G, Hilgetag CC. Technical considerations of a game-theoretical approach for lesion symptom mapping. BMC Neurosci 2016; 17:40. [PMID: 27349961 PMCID: PMC4924231 DOI: 10.1186/s12868-016-0275-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 06/15/2016] [Indexed: 08/27/2023] Open
Abstract
Background Various strategies have been used for inferring brain functions from stroke lesions. We explored a new mathematical approach based on game theory, the so-called multi-perturbation Shapley value analysis (MSA), to assess causal function localizations and interactions from multiple perturbation data. We applied MSA to a dataset composed of lesion patterns of 148 acute stroke patients and their National Institutes of Health Stroke Scale (NIHSS) scores, to systematically investigate the influence of different parameter settings on the outcomes of the approach. Specifically, we investigated aspects of MSA methodology including the choice of the predictor algorithm (typology and kernel functions), training dataset (original versus binary), as well as the influence of lesion thresholds. We assessed the suitability of MSA for processing real clinical lesion data and established the central parameters for this analysis. Results We derived general recommendations for the analysis of clinical datasets by MSA and showed that, for the studied dataset, the best approach was to use a linear-kernel support vector machine predictor, trained with a binary training dataset, where the binarization was implemented through a median threshold of lesion size for each region. We demonstrated that the results obtained with different MSA variants lead to almost identical results as the basic MSA. Conclusions MSA is a feasible approach for the multivariate lesion analysis of clinical stroke data. Informed choices need to be made to set parameters that may affect the analysis outcome.
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Affiliation(s)
- Melissa Zavaglia
- Department of Computational Neuroscience, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, 20246, Hamburg, Germany. .,School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany.
| | - Nils D Forkert
- Department of Computational Neuroscience, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, 20246, Hamburg, Germany.,Department of Radiology and Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
| | - Bastian Cheng
- Department of Neurology, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, 20246, Hamburg, Germany
| | - Christian Gerloff
- Department of Neurology, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, 20246, Hamburg, Germany
| | - Götz Thomalla
- Department of Neurology, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, 20246, Hamburg, Germany
| | - Claus C Hilgetag
- Department of Computational Neuroscience, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, 20246, Hamburg, Germany.,Department of Health Sciences, Boston University, 635 Commonwealth Ave., Boston, MA, 02215, USA
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Zavaglia M, Forkert ND, Cheng B, Gerloff C, Thomalla G, Hilgetag CC. Mapping causal functional contributions derived from the clinical assessment of brain damage after stroke. NEUROIMAGE-CLINICAL 2015; 9:83-94. [PMID: 26448908 PMCID: PMC4544394 DOI: 10.1016/j.nicl.2015.07.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/03/2015] [Accepted: 07/15/2015] [Indexed: 11/26/2022]
Abstract
Lesion analysis reveals causal contributions of brain regions to mental functions, aiding the understanding of normal brain function as well as rehabilitation of brain-damaged patients. We applied a novel lesion inference technique based on game theory, Multi-perturbation Shapley value Analysis (MSA), to a large clinical lesion dataset. We used MSA to analyze the lesion patterns of 148 acute stroke patients together with their neurological deficits, as assessed by the National Institutes of Health Stroke Scale (NIHSS). The results revealed regional functional contributions to essential behavioral and cognitive functions as reflected in the NIHSS, particularly by subcortical structures. There were also side specific differences of functional contributions between the right and left hemispheric brain regions which may reflect the dominance of the left hemispheric syndrome aphasia in the NIHSS. Comparison of MSA to established lesion inference methods demonstrated the feasibility of the approach for analyzing clinical data and indicated its capability for objectively inferring functional contributions from multiple injured, potentially interacting sites, at the cost of having to predict the outcome of unknown lesion configurations. The analysis of regional functional contributions to neurological symptoms measured by the NIHSS contributes to the interpretation of this widely used standardized stroke scale in clinical practice as well as clinical trials and provides a first approximation of a 'map of stroke'.
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Key Words
- CT, computer tomography
- DWI, diffusion weighted imaging
- Game-theory
- Lesion inference
- MAPP, Multi-Area Pattern Prediction
- MCA, middle cerebral artery
- MRI, magnetic resonance imaging
- MSA, Multi-perturbation Shapley value Analysis
- MVPA, Multi-Variate Pattern Analysis
- Multi-perturbation Shapley value Analysis (MSA)
- NIHSS
- NIHSS, National Institutes of Health Stroke Scale
- SVM, support vector machine
- VAL, voxel-based analysis of lesions
- VBM, voxel-based morphometry
- VLSC, VOI-based Lesion Symptom Correlation
- VLSM, Volume-based Lesion Symptom Mapping
- VOI, volume of interest
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Affiliation(s)
- Melissa Zavaglia
- Department of Computational Neuroscience, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, Hamburg 20246, Germany ; School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, Bremen 28759, Germany
| | - Nils D Forkert
- Department of Computational Neuroscience, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, Hamburg 20246, Germany ; Department of Radiology, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - Bastian Cheng
- Department of Neurology, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, Hamburg 20246, Germany
| | - Christian Gerloff
- Department of Neurology, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, Hamburg 20246, Germany
| | - Götz Thomalla
- Department of Neurology, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, Hamburg 20246, Germany
| | - Claus C Hilgetag
- Department of Computational Neuroscience, University Medical Center Eppendorf, Hamburg University, Martinistraße 52, Hamburg 20246, Germany ; Department of Health Sciences, Boston University, 635 Commonwealth Ave., Boston, MA 02215, USA
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Hulme OJ, Whiteley L, Shipp S. Spatially distributed encoding of covert attentional shifts in human thalamus. J Neurophysiol 2010; 104:3644-56. [PMID: 20844113 PMCID: PMC3007633 DOI: 10.1152/jn.00303.2010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Spatial attention modulates signal processing within visual nuclei of the thalamus—but do other nuclei govern the locus of attention in top-down mode? We examined functional MRI (fMRI) data from three subjects performing a task requiring covert attention to 1 of 16 positions in a circular array. Target position was cued after stimulus offset, requiring subjects to perform target detection from iconic visual memory. We found positionally specific responses at multiple thalamic sites, with individual voxels activating at more than one direction of attentional shift. Voxel clusters at anatomically equivalent sites across subjects revealed a broad range of directional tuning at each site, with little sign of contralateral bias. By reference to a thalamic atlas, we identified the nuclear correspondence of the four most reliably activated sites across subjects: mediodorsal/central-intralaminar (oculomotor thalamus), caudal intralaminar/parafascicular, suprageniculate/limitans, and medial pulvinar/lateral posterior. Hence, the cortical network generating a top-down control signal for relocating attention acts in concert with a spatially selective thalamic apparatus—the set of active nuclei mirroring the thalamic territory of cortical “eye-field” areas, thus supporting theories which propose the visuomotor origins of covert attentional selection.
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Affiliation(s)
- Oliver J Hulme
- Department of Vision Science, UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
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