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Downey JE, Schone HR, Foldes ST, Greenspon C, Liu F, Verbaarschot C, Biro D, Satzer D, Moon CH, Coffman BA, Youssofzadeh V, Fields D, Hobbs TG, Okorokova E, Tyler-Kabara EC, Warnke PC, Gonzalez-Martinez J, Hatsopoulos NG, Bensmaia SJ, Boninger ML, Gaunt RA, Collinger JL. A roadmap for implanting microelectrode arrays to evoke tactile sensations through intracortical microstimulation. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.04.26.24306239. [PMID: 38712177 PMCID: PMC11071570 DOI: 10.1101/2024.04.26.24306239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Intracortical microstimulation (ICMS) is a method for restoring sensation to people with paralysis as part of a bidirectional brain-computer interface to restore upper limb function. Evoking tactile sensations of the hand through ICMS requires precise targeting of implanted electrodes. Here we describe the presurgical imaging procedures used to generate functional maps of the hand area of the somatosensory cortex and subsequent planning that guided the implantation of intracortical microelectrode arrays. In five participants with cervical spinal cord injury, across two study locations, this procedure successfully enabled ICMS-evoked sensations localized to at least the first four digits of the hand. The imaging and planning procedures developed through this clinical trial provide a roadmap for other brain-computer interface studies to ensure successful placement of stimulation electrodes.
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Affiliation(s)
- John E Downey
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL
| | - Hunter R Schone
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA
| | - Stephen T Foldes
- Department of Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ
| | - Charles Greenspon
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL
| | - Fang Liu
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA
| | - Ceci Verbaarschot
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA
| | - Daniel Biro
- Department of Neurological Surgery, University of Chicago, Chicago, IL
| | - David Satzer
- Department of Neurological Surgery, University of Chicago, Chicago, IL
| | - Chan Hong Moon
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA
| | - Brian A Coffman
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA
| | | | - Daryl Fields
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA
| | - Taylor G Hobbs
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA
| | - Elizaveta Okorokova
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL
| | | | - Peter C Warnke
- Department of Neurological Surgery, University of Chicago, Chicago, IL
| | | | - Nicholas G Hatsopoulos
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL
- Committee on Computation Neuroscience, University of Chicago, Chicago, IL
- Neuroscience Institute, University of Chicago, Chicago, IL
| | - Sliman J Bensmaia
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL
- Committee on Computation Neuroscience, University of Chicago, Chicago, IL
- Neuroscience Institute, University of Chicago, Chicago, IL
| | - Michael L Boninger
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA
| | - Robert A Gaunt
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA
| | - Jennifer L Collinger
- Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, PA
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA
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2
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Ambron E, Garcea FE, Cason S, Medina J, Detre JA, Coslett HB. The influence of hand posture on tactile processing: Evidence from a 7T functional magnetic resonance imaging study. Cortex 2024; 173:138-149. [PMID: 38394974 DOI: 10.1016/j.cortex.2023.12.019] [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: 05/26/2023] [Revised: 09/19/2023] [Accepted: 12/13/2023] [Indexed: 02/25/2024]
Abstract
Although behavioral evidence has shown that postural changes influence the ability to localize or detect tactile stimuli, little is known regarding the brain areas that modulate these effects. This 7T functional magnetic resonance imaging (fMRI) study explores the effects of touch of the hand as a function of hand location (right or left side of the body) and hand configuration (open or closed). We predicted that changes in hand configuration would be represented in contralateral primary somatosensory cortex (S1) and the anterior intraparietal area (aIPS), whereas change in position of the hand would be associated with alterations in activation in the superior parietal lobule. Multivoxel pattern analysis and a region of interest approach partially supported our predictions. Decoding accuracy for hand location was above chance level in superior parietal lobule (SPL) and in the anterior intraparietal (aIPS) area; above chance classification of hand configuration was observed in SPL and S1. This evidence confirmed the role of the parietal cortex in postural effects on touch and the possible role of S1 in coding the body form representation of the hand.
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Affiliation(s)
- Elisabetta Ambron
- Laboratory for Cognition and Neural Stimulation, Perelman School of Medicine at the University of Pennsylvania, USA; Department Neurology, University of Pennsylvania, USA.
| | - Frank E Garcea
- Department of Neurosurgery, University of Rochester Medical Center, NY, USA; Department of Neuroscience, University of Rochester Medical Center, NY, USA; Del Monte Institute for Neuroscience, University of Rochester Medical Center, NY, USA.
| | - Samuel Cason
- Laboratory for Cognition and Neural Stimulation, Perelman School of Medicine at the University of Pennsylvania, USA; Department Neurology, University of Pennsylvania, USA
| | - Jared Medina
- Department of Psychological and Brain Sciences, University of Delaware, USA
| | - John A Detre
- Department Neurology, University of Pennsylvania, USA
| | - H Branch Coslett
- Laboratory for Cognition and Neural Stimulation, Perelman School of Medicine at the University of Pennsylvania, USA; Department Neurology, University of Pennsylvania, USA
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3
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Brewer AA, Barton B. Cortical field maps across human sensory cortex. Front Comput Neurosci 2023; 17:1232005. [PMID: 38164408 PMCID: PMC10758003 DOI: 10.3389/fncom.2023.1232005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Accepted: 11/07/2023] [Indexed: 01/03/2024] Open
Abstract
Cortical processing pathways for sensory information in the mammalian brain tend to be organized into topographical representations that encode various fundamental sensory dimensions. Numerous laboratories have now shown how these representations are organized into numerous cortical field maps (CMFs) across visual and auditory cortex, with each CFM supporting a specialized computation or set of computations that underlie the associated perceptual behaviors. An individual CFM is defined by two orthogonal topographical gradients that reflect two essential aspects of feature space for that sense. Multiple adjacent CFMs are then organized across visual and auditory cortex into macrostructural patterns termed cloverleaf clusters. CFMs within cloverleaf clusters are thought to share properties such as receptive field distribution, cortical magnification, and processing specialization. Recent measurements point to the likely existence of CFMs in the other senses, as well, with topographical representations of at least one sensory dimension demonstrated in somatosensory, gustatory, and possibly olfactory cortical pathways. Here we discuss the evidence for CFM and cloverleaf cluster organization across human sensory cortex as well as approaches used to identify such organizational patterns. Knowledge of how these topographical representations are organized across cortex provides us with insight into how our conscious perceptions are created from our basic sensory inputs. In addition, studying how these representations change during development, trauma, and disease serves as an important tool for developing improvements in clinical therapies and rehabilitation for sensory deficits.
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Affiliation(s)
- Alyssa A. Brewer
- mindSPACE Laboratory, Departments of Cognitive Sciences and Language Science (by Courtesy), Center for Hearing Research, University of California, Irvine, Irvine, CA, United States
| | - Brian Barton
- mindSPACE Laboratory, Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, United States
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4
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Guekos A, Cole DM, Dörig M, Stämpfli P, Schibli L, Schuetz P, Schweinhardt P, Meier ML. BackWards - Unveiling the brain's topographic organization of paraspinal sensory input. Neuroimage 2023; 283:120431. [PMID: 37914091 DOI: 10.1016/j.neuroimage.2023.120431] [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: 06/26/2023] [Revised: 10/24/2023] [Accepted: 10/27/2023] [Indexed: 11/03/2023] Open
Abstract
Cortical reorganization and its potential pathological significance are being increasingly studied in musculoskeletal disorders such as chronic low back pain (CLBP) patients. However, detailed sensory-topographic maps of the human back are lacking, and a baseline characterization of such representations, reflecting the somatosensory organization of the healthy back, is needed before exploring potential sensory map reorganization. To this end, a novel pneumatic vibrotactile stimulation method was used to stimulate paraspinal sensory afferents, while studying their cortical representations in unprecedented detail. In 41 young healthy participants, vibrotactile stimulations at 20 Hz and 80 Hz were applied bilaterally at nine locations along the thoracolumbar axis while functional magnetic resonance imaging (fMRI) was performed. Model-based whole-brain searchlight representational similarity analysis (RSA) was used to investigate the organizational structure of brain activity patterns evoked by thoracolumbar sensory inputs. A model based on segmental distances best explained the similarity structure of brain activity patterns that were located in different areas of sensorimotor cortices, including the primary somatosensory and motor cortices and parts of the superior parietal cortex, suggesting that these brain areas process sensory input from the back in a "dermatomal" manner. The current findings provide a sound basis for testing the "cortical map reorganization theory" and its pathological relevance in CLBP.
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Affiliation(s)
- Alexandros Guekos
- Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Decision Neuroscience Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), Zurich, Switzerland.
| | - David M Cole
- Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital, University of Zurich, Switzerland
| | - Monika Dörig
- Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; School of Engineering and Architecture, Lucerne University of Applied Sciences and Arts, Horw, Switzerland
| | - Philipp Stämpfli
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric University Hospital, University of Zurich, Switzerland; MR-Center of the Psychiatric University Hospital, Department of Child and Adolescent Psychiatry, University of Zurich, Zurich, Switzerland
| | - Louis Schibli
- Competence Center Thermal Energy Storage, Lucerne University of Applied Sciences and Art, Horw, Switzerland
| | - Philipp Schuetz
- Competence Center Thermal Energy Storage, Lucerne University of Applied Sciences and Art, Horw, Switzerland
| | - Petra Schweinhardt
- Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), Zurich, Switzerland
| | - Michael L Meier
- Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), Zurich, Switzerland
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Asghar M, Sanchez-Panchuelo R, Schluppeck D, Francis S. Two-Dimensional Population Receptive Field Mapping of Human Primary Somatosensory Cortex. Brain Topogr 2023; 36:816-834. [PMID: 37634160 PMCID: PMC10522535 DOI: 10.1007/s10548-023-01000-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/09/2023] [Indexed: 08/29/2023]
Abstract
Functional magnetic resonance imaging can provide detailed maps of how sensory space is mapped in the human brain. Here, we use a novel 16 stimulator setup (a 4 × 4 grid) to measure two-dimensional sensory maps of between and within-digit (D2-D4) space using high spatial-resolution (1.25 mm isotropic) imaging at 7 Tesla together with population receptive field (pRF) mapping in 10 participants. Using a 2D Gaussian pRF model, we capture maps of the coverage of digits D2-D5 across Brodmann areas and estimate pRF size and shape. In addition, we compare results to previous studies that used fewer stimulators by constraining pRF models to a 1D Gaussian Between Digit or 1D Gaussian Within Digit model. We show that pRFs across somatosensory areas tend to have a strong preference to cover the within-digit axis. We show an increase in pRF size moving from D2-D5. We quantify pRF shapes in Brodmann area (BA) 3b, 3a, 1, 2 and show differences in pRF size in Brodmann areas 3a-2, with larger estimates for BA2. Generally, the 2D Gaussian pRF model better represents pRF coverage maps generated by our data, which itself is produced from a 2D stimulation grid.
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Affiliation(s)
- Michael Asghar
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
| | - Rosa Sanchez-Panchuelo
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
- University Hospitals Birmingham NHS Foundation Trust, Nottingham, UK
| | | | - Susan Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
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6
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Rabe F, Kikkert S, Wenderoth N. Performing a vibrotactile discrimination task modulates finger representations in primary somatosensory cortex. J Neurophysiol 2023; 130:1015-1027. [PMID: 37671429 PMCID: PMC10649835 DOI: 10.1152/jn.00428.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 08/29/2023] [Accepted: 08/31/2023] [Indexed: 09/07/2023] Open
Abstract
It is well established that vibrotactile stimuli are represented in somatotopic maps. However, less is known about whether these somatotopic representations are modulated by task demands and maybe even in the absence of tactile input. Here, we used a vibrotactile discrimination task as a tool to investigate these questions in further detail. Participants were required to actively perceive and process tactile stimuli in comparison to a no-task control condition where identical stimuli were passively perceived (no-memory condition). Importantly, both vibrotactile stimuli were either applied to the right index or little finger, allowing us to investigate whether cognitive task demands shape finger representations in primary somatosensory cortex (S1). Using multivoxel pattern analysis and representational similarity analysis, we found that S1 finger representations were more distinct during the memory than the no-memory condition. Interestingly, this effect was not only observed while tactile stimuli were presented but also during the delay period (i.e., in the absence of tactile stimulation). Our findings imply that when individuals are required to focus on tactile stimuli, retain them in their memory, and engage in active processing of distinctive stimulus features, this exerts a modulatory effect on the finger representations present in S1.NEW & NOTEWORTHY Using multivoxel pattern analysis, we found that discrimination task demands shape finger representations in the contralateral primary somatosensory cortex (S1), and that somatotopic representations are modulated by task demands not only during tactile stimulation but also to a certain extent in the absence of tactile input.
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Affiliation(s)
- Finn Rabe
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
| | - Sanne Kikkert
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Nicole Wenderoth
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zürich, Zurich, Switzerland
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7
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Sanders Z, Dempsey‐Jones H, Wesselink DB, Edmondson LR, Puckett AM, Saal HP, Makin TR. Similar somatotopy for active and passive digit representation in primary somatosensory cortex. Hum Brain Mapp 2023; 44:3568-3585. [PMID: 37145934 PMCID: PMC10203813 DOI: 10.1002/hbm.26298] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 12/11/2022] [Accepted: 03/13/2023] [Indexed: 05/07/2023] Open
Abstract
Scientists traditionally use passive stimulation to examine the organisation of primary somatosensory cortex (SI). However, given the close, bidirectional relationship between the somatosensory and motor systems, active paradigms involving free movement may uncover alternative SI representational motifs. Here, we used 7 Tesla functional magnetic resonance imaging to compare hallmark features of SI digit representation between active and passive tasks which were unmatched on task or stimulus properties. The spatial location of digit maps, somatotopic organisation, and inter-digit representational structure were largely consistent between tasks, indicating representational consistency. We also observed some task differences. The active task produced higher univariate activity and multivariate representational information content (inter-digit distances). The passive task showed a trend towards greater selectivity for digits versus their neighbours. Our findings highlight that, while the gross features of SI functional organisation are task invariant, it is important to also consider motor contributions to digit representation.
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Affiliation(s)
- Zeena‐Britt Sanders
- Wellcome Centre of Integrative NeuroimagingFMRIB, John Radcliffe HospitalOxfordUK
| | - Harriet Dempsey‐Jones
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUK
- School of PsychologyThe University of QueenslandBrisbaneAustralia
| | - Daan B. Wesselink
- Wellcome Centre of Integrative NeuroimagingFMRIB, John Radcliffe HospitalOxfordUK
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUK
| | | | - Alexander M. Puckett
- School of PsychologyThe University of QueenslandBrisbaneAustralia
- Queensland Brain InstituteThe University of QueenslandBrisbaneAustralia
| | - Hannes P. Saal
- Queensland Brain InstituteThe University of QueenslandBrisbaneAustralia
| | - Tamar R. Makin
- Wellcome Centre of Integrative NeuroimagingFMRIB, John Radcliffe HospitalOxfordUK
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUK
- MRC Cognition and Brain Sciences UnitUniversity of CambridgeCambridgeUK
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Doehler J, Northall A, Liu P, Fracasso A, Chrysidou A, Speck O, Lohmann G, Wolbers T, Kuehn E. The 3D Structural Architecture of the Human Hand Area Is Nontopographic. J Neurosci 2023; 43:3456-3476. [PMID: 37001994 PMCID: PMC10184749 DOI: 10.1523/jneurosci.1692-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 02/15/2023] [Accepted: 03/15/2023] [Indexed: 04/03/2023] Open
Abstract
The functional topography of the human primary somatosensory cortex hand area is a widely studied model system to understand sensory organization and plasticity. It is so far unclear whether the underlying 3D structural architecture also shows a topographic organization. We used 7 Tesla (7T) magnetic resonance imaging (MRI) data to quantify layer-specific myelin, iron, and mineralization in relation to population receptive field maps of individual finger representations in Brodman area 3b (BA 3b) of human S1 in female and male younger adults. This 3D description allowed us to identify a characteristic profile of layer-specific myelin and iron deposition in the BA 3b hand area, but revealed an absence of structural differences, an absence of low-myelin borders, and high similarity of 3D microstructure profiles between individual fingers. However, structural differences and borders were detected between the hand and face areas. We conclude that the 3D structural architecture of the human hand area is nontopographic, unlike in some monkey species, which suggests a high degree of flexibility for functional finger organization and a new perspective on human topographic plasticity.SIGNIFICANCE STATEMENT Using ultra-high-field MRI, we provide the first comprehensive in vivo description of the 3D structural architecture of the human BA 3b hand area in relation to functional population receptive field maps. High similarity of precise finger-specific 3D profiles, together with an absence of structural differences and an absence of low-myelin borders between individual fingers, reveals the 3D structural architecture of the human hand area to be nontopographic. This suggests reduced structural limitations to cortical plasticity and reorganization and allows for shared representational features across fingers.
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Affiliation(s)
- Juliane Doehler
- Institute for Cognitive Neurology and Dementia Research, Medical Faculty, Otto-von-Guericke University Magdeburg, 39120 Magdeburg, Germany
- German Center for Neurodegenerative Diseases, 39120 Magdeburg, Germany
| | - Alicia Northall
- Institute for Cognitive Neurology and Dementia Research, Medical Faculty, Otto-von-Guericke University Magdeburg, 39120 Magdeburg, Germany
- German Center for Neurodegenerative Diseases, 39120 Magdeburg, Germany
| | - Peng Liu
- Institute for Cognitive Neurology and Dementia Research, Medical Faculty, Otto-von-Guericke University Magdeburg, 39120 Magdeburg, Germany
- German Center for Neurodegenerative Diseases, 39120 Magdeburg, Germany
| | - Alessio Fracasso
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Anastasia Chrysidou
- Institute for Cognitive Neurology and Dementia Research, Medical Faculty, Otto-von-Guericke University Magdeburg, 39120 Magdeburg, Germany
- German Center for Neurodegenerative Diseases, 39120 Magdeburg, Germany
| | - Oliver Speck
- German Center for Neurodegenerative Diseases, 39120 Magdeburg, Germany
- Department of Biomedical Magnetic Resonance, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany
- Center for Behavioral Brain Sciences, 39120 Magdeburg, Germany
- Leibniz Institute for Neurobiology, 39120 Magdeburg, Germany
| | - Gabriele Lohmann
- Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany
| | - Thomas Wolbers
- German Center for Neurodegenerative Diseases, 39120 Magdeburg, Germany
- Center for Behavioral Brain Sciences, 39120 Magdeburg, Germany
| | - Esther Kuehn
- Hertie Institute for Clinical Brain Research, 72076 Tübingen, Germany
- Institute for Cognitive Neurology and Dementia Research, Medical Faculty, Otto-von-Guericke University Magdeburg, 39120 Magdeburg, Germany
- German Center for Neurodegenerative Diseases, 39120 Magdeburg, Germany
- Center for Behavioral Brain Sciences, 39120 Magdeburg, Germany
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9
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Rosenthal IA, Bashford L, Kellis S, Pejsa K, Lee B, Liu C, Andersen RA. S1 represents multisensory contexts and somatotopic locations within and outside the bounds of the cortical homunculus. Cell Rep 2023; 42:112312. [PMID: 37002922 PMCID: PMC10544688 DOI: 10.1016/j.celrep.2023.112312] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 02/06/2023] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Recent literature suggests that tactile events are represented in the primary somatosensory cortex (S1) beyond its long-established topography; in addition, the extent to which S1 is modulated by vision remains unclear. To better characterize S1, human electrophysiological data were recorded during touches to the forearm or finger. Conditions included visually observed physical touches, physical touches without vision, and visual touches without physical contact. Two major findings emerge from this dataset. First, vision strongly modulates S1 area 1, but only if there is a physical element to the touch, suggesting that passive touch observation is insufficient to elicit neural responses. Second, despite recording in a putative arm area of S1, neural activity represents both arm and finger stimuli during physical touches. Arm touches are encoded more strongly and specifically, supporting the idea that S1 encodes tactile events primarily through its topographic organization but also more generally, encompassing other areas of the body.
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Affiliation(s)
- Isabelle A Rosenthal
- Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA.
| | - Luke Bashford
- Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA
| | - Spencer Kellis
- Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA; Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA 90033, USA; USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA 90033, USA
| | - Kelsie Pejsa
- Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA
| | - Brian Lee
- Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA 90033, USA; USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA 90033, USA
| | - Charles Liu
- Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA 90033, USA; USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA 90033, USA; Rancho Los Amigos National Rehabilitation Center, Downey, CA 90242, USA
| | - Richard A Andersen
- Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; T&C Chen Brain-machine Interface Center, California Institute of Technology, Pasadena, CA 91125, USA
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10
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Fukuda S, Tsujinaka R, Oda H, Hamada N, Matsuoka M, Hiraoka K. Suppression of perceptual sensitivity to digital nerve stimulation induced by afferent volley from digital nerve of contralateral homologous finger. Neuroreport 2023; 34:436-440. [PMID: 37096762 DOI: 10.1097/wnr.0000000000001909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
The purpose of the present study is to investigate whether perceptual sensitivity to digital nerve stimulation is modulated by the afferent volley from the digital nerve of a contralateral finger. Fifteen healthy humans participated in this study. A test stimulus was given to the right-hand index finger, and a conditioning stimulus was given to one of the five fingers on the left hand 20, 30, or 40 ms before the test stimulus. The perceptual threshold of the finger stimulation was measured. The perceptual threshold of the test stimulus was significantly increased by a conditioning stimulus to the left-hand index finger given 40 ms before the test stimulus. In contrast, the threshold was not significantly changed by a conditioning stimulus to any finger other than the index finger. Perceptual sensitivity to digital nerve stimulation is suppressed by the afferent volley from the digital nerve of the contralateral homologous finger. This means that the afferent volley from the digital nerve suppresses the homologous finger representation in the ipsilateral somatosensory areas. These findings can be explained by the view that the afferent volley from the digital nerve of the index finger projects to the index finger representation in the contralateral primary sensory cortex and that the interhemispheric transcallosal inhibitory drive is provided from the secondary sensory cortex to the homologous finger representation in the contralateral secondary sensory cortex.
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Affiliation(s)
- Shiho Fukuda
- Graduate School of Rehabilitation Science, Osaka Metropolitan University
| | - Ryo Tsujinaka
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University
| | - Hitoshi Oda
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University
| | - Naoki Hamada
- Graduate School of Rehabilitation Science, Osaka Metropolitan University
| | - Masakazu Matsuoka
- Graduate School of Rehabilitation Science, Osaka Metropolitan University
| | - Koichi Hiraoka
- School of Medicine, Osaka Metropolitan University, Habikino city, Osaka, Japan
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11
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Kikkert S, Sonar HA, Freund P, Paik J, Wenderoth N. Hand and face somatotopy shown using MRI-safe vibrotactile stimulation with a novel soft pneumatic actuator (SPA)-skin interface. Neuroimage 2023; 269:119932. [PMID: 36750151 DOI: 10.1016/j.neuroimage.2023.119932] [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: 04/22/2022] [Revised: 01/23/2023] [Accepted: 02/02/2023] [Indexed: 02/07/2023] Open
Abstract
The exact somatotopy of the human facial representation in the primary somatosensory cortex (S1) remains debated. One reason that progress has been hampered is due to the methodological challenge of how to apply automated vibrotactile stimuli to face areas in a manner that is: (1) reliable despite differences in the curvatures of face locations; and (2) MR-compatible and free of MR-interference artefacts when applied in the MR head-coil. Here we overcome this challenge by using soft pneumatic actuator (SPA) technology. SPAs are made of a soft silicon material and can be in- or deflated by means of airflow, have a small diameter, and are flexible in structure, enabling good skin contact even on curved body surfaces (as on the face). To validate our approach, we first mapped the well-characterised S1 finger layout using this novel device and confirmed that tactile stimulation of the fingers elicited characteristic somatotopic finger activations in S1. We then used the device to automatically and systematically deliver somatosensory stimulation to different face locations. We found that the forehead representation was least distant from the representation of the hand. Within the face representation, we found that the lip representation is most distant from the forehead representation, with the chin represented in between. Together, our results demonstrate that this novel MR compatible device produces robust and clear somatotopic representational patterns using vibrotactile stimulation through SPA-technology.
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Affiliation(s)
- Sanne Kikkert
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland; Spinal Cord Injury Center Balgrist, University Hospital Zürich, University of Zürich, Zürich, Switzerland.
| | | | - Patrick Freund
- Spinal Cord Injury Center Balgrist, University Hospital Zürich, University of Zürich, Zürich, Switzerland
| | - Jamie Paik
- Reconfigurable Robotics Lab, EPFL, Lausanne, Switzerland
| | - Nicole Wenderoth
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
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12
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Morphology, Connectivity, and Encoding Features of Tactile and Motor Representations of the Fingers in the Human Precentral and Postcentral Gyrus. J Neurosci 2023; 43:1572-1589. [PMID: 36717227 PMCID: PMC10008061 DOI: 10.1523/jneurosci.1976-21.2022] [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: 09/08/2021] [Revised: 09/11/2022] [Accepted: 09/14/2022] [Indexed: 02/01/2023] Open
Abstract
Despite the tight coupling between sensory and motor processing for fine manipulation in humans, it is not yet totally clear which specific properties of the fingers are mapped in the precentral and postcentral gyrus. We used fMRI to compare the morphology, connectivity, and encoding of the motor and tactile finger representations (FRs) in the precentral and postcentral gyrus of 25 5-fingered participants (8 females). Multivoxel pattern and structural and functional connectivity analyses demonstrated the existence of distinct motor and tactile FRs within both the precentral and postcentral gyrus, integrating finger-specific motor and tactile information. Using representational similarity analysis, we found that the motor and tactile FRs in the sensorimotor cortex were described by the perceived structure of the hand better than by the actual hand anatomy or other functional models (finger kinematics, muscles synergies). We then studied a polydactyly individual (i.e., with a congenital 6-fingered hand) showing superior manipulation abilities and divergent anatomic-functional hand properties. The perceived hand model was still the best model for tactile representations in the precentral and postcentral gyrus, while finger kinematics better described motor representations in the precentral gyrus. We suggest that, under normal conditions (i.e., in subjects with a standard hand anatomy), the sensorimotor representations of the 5 fingers in humans converge toward a model of perceived hand anatomy, deviating from the real hand structure, as the best synthesis between functional and structural features of the hand.SIGNIFICANCE STATEMENT Distinct motor and tactile finger representations exist in both the precentral and postcentral gyrus, supported by a finger-specific pattern of anatomic and functional connectivity across modalities. At the representational level, finger representations reflect the perceived structure of the hand, which might result from an adapting process harmonizing (i.e., uniformizing) the encoding of hand function and structure in the precentral and postcentral gyrus. The same analyses performed in an extremely rare polydactyly subject showed that the emergence of such representational geometry is also found in neuromechanical variants with different hand anatomy and function. However, the harmonization process across the precentral and postcentral gyrus might not be possible because of divergent functional-structural properties of the hand and associated superior manipulation abilities.
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13
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de Oliveira ÍAF, Siero JCW, Dumoulin SO, van der Zwaag W. Improved Selectivity in 7 T Digit Mapping Using VASO-CBV. Brain Topogr 2023; 36:23-31. [PMID: 36517699 PMCID: PMC9834127 DOI: 10.1007/s10548-022-00932-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022]
Abstract
Functional magnetic resonance imaging (fMRI) at Ultra-high field (UHF, ≥ 7 T) benefits from significant gains in the BOLD contrast-to-noise ratio (CNR) and temporal signal-to-noise ratio (tSNR) compared to conventional field strengths (3 T). Although these improvements enabled researchers to study the human brain to unprecedented spatial resolution, the blood pooling effect reduces the spatial specificity of the widely-used gradient-echo BOLD acquisitions. In this context, vascular space occupancy (VASO-CBV) imaging may be advantageous since it is proposed to have a higher spatial specificity than BOLD. We hypothesized that the assumed higher specificity of VASO-CBV imaging would translate to reduced overlap in fine-scale digit representation maps compared to BOLD-based digit maps. We used sub-millimeter resolution VASO fMRI at 7 T to map VASO-CBV and BOLD responses simultaneously in the motor and somatosensory cortices during individual finger movement tasks. We assessed the cortical overlap in different ways, first by calculating similarity coefficient metrics (DICE and Jaccard) and second by calculating selectivity measures. In addition, we demonstrate a consistent topographical organization of the targeted digit representations (thumb-index-little finger) in the motor areas. We show that the VASO-CBV responses yielded less overlap between the digit clusters than BOLD, and other selectivity measures were higher for VASO-CBV too. In summary, these results were consistent across metrics and participants, confirming the higher spatial specificity of VASO-CBV compared to BOLD.
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Affiliation(s)
- Ícaro A. F. de Oliveira
- grid.458380.20000 0004 0368 8664Spinoza Centre for Neuroimaging, Meibergdreef 75, 1105 BK Amsterdam, The Netherlands ,grid.12380.380000 0004 1754 9227Experimental and Applied Psychology, VU University, Amsterdam, The Netherlands ,grid.419918.c0000 0001 2171 8263Computational Cognitive Neuroscience and Neuroimaging, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Jeroen C. W. Siero
- grid.458380.20000 0004 0368 8664Spinoza Centre for Neuroimaging, Meibergdreef 75, 1105 BK Amsterdam, The Netherlands ,grid.7692.a0000000090126352Radiology, Utrecht Center for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Serge O. Dumoulin
- grid.458380.20000 0004 0368 8664Spinoza Centre for Neuroimaging, Meibergdreef 75, 1105 BK Amsterdam, The Netherlands ,grid.12380.380000 0004 1754 9227Experimental and Applied Psychology, VU University, Amsterdam, The Netherlands ,grid.419918.c0000 0001 2171 8263Computational Cognitive Neuroscience and Neuroimaging, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands ,grid.5477.10000000120346234Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
| | - Wietske van der Zwaag
- grid.458380.20000 0004 0368 8664Spinoza Centre for Neuroimaging, Meibergdreef 75, 1105 BK Amsterdam, The Netherlands ,grid.419918.c0000 0001 2171 8263Computational Cognitive Neuroscience and Neuroimaging, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
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14
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Khalife S, Francis ST, Schluppeck D, Sánchez-Panchuelo RM, Besle J. Fast Event-Related Mapping of Population Fingertip Tuning Properties in Human Sensorimotor Cortex at 7T. eNeuro 2022; 9:ENEURO.0069-22.2022. [PMID: 36194620 PMCID: PMC9480917 DOI: 10.1523/eneuro.0069-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 07/11/2022] [Accepted: 07/31/2022] [Indexed: 12/15/2022] Open
Abstract
fMRI studies that investigate somatotopic tactile representations in the human cortex typically use either block or phase-encoded stimulation designs. Event-related (ER) designs allow for more flexible and unpredictable stimulation sequences than the other methods, but they are less efficient. Here, we compared an efficiency-optimized fast ER design (2.8-s average intertrial interval; ITI) to a conventional slow ER design (8-s average ITI) for mapping voxelwise fingertip tactile tuning properties in the sensorimotor cortex of six participants at 7 Tesla. The fast ER design yielded more reliable responses compared with the slow ER design, but with otherwise similar tuning properties. Concatenating the fast and slow ER data, we demonstrate in each individual brain the existence of two separate somatotopically-organized tactile representations of the fingertips, one in the primary somatosensory cortex (S1) on the postcentral gyrus, and the other shared across the motor and premotor cortices on the precentral gyrus. In both S1 and motor representations, fingertip selectivity decreased progressively, from narrowly-tuned Brodmann area (BA) 3b and BA4a, respectively, toward associative parietal and frontal regions that responded equally to all fingertips, suggesting increasing information integration along these two pathways. In addition, fingertip selectivity in S1 decreased from the cortical representation of the thumb to that of the pinky.
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Affiliation(s)
- Sarah Khalife
- Department of Psychology, American University of Beirut, Beirut, 11072020, Lebanon
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, NG72RD, United Kingdom
- National Institute for Health and Care Research Nottingham Biomedical Research Centre, Nottingham University Hospitals National Health Service Trust, University of Nottingham, Nottingham, NG72RD, United Kingdom
| | - Denis Schluppeck
- Visual Neuroscience Group, School of Psychology, University of Nottingham, Nottingham, NG72RD, United Kingdom
| | - Rosa-Maria Sánchez-Panchuelo
- National Institute for Health and Care Research Nottingham Biomedical Research Centre, Nottingham University Hospitals National Health Service Trust, University of Nottingham, Nottingham, NG72RD, United Kingdom
| | - Julien Besle
- Department of Psychology, American University of Beirut, Beirut, 11072020, Lebanon
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15
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Cole DM, Stämpfli P, Gandia R, Schibli L, Gantner S, Schuetz P, Meier ML. In the back of your mind: Cortical mapping of paraspinal afferent inputs. Hum Brain Mapp 2022; 43:4943-4953. [PMID: 35979921 PMCID: PMC9582373 DOI: 10.1002/hbm.26052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/22/2022] [Accepted: 08/02/2022] [Indexed: 11/06/2022] Open
Abstract
Topographic organisation is a hallmark of vertebrate cortex architecture, characterised by ordered projections of the body's sensory surfaces onto brain systems. High-resolution functional magnetic resonance imaging (fMRI) has proven itself as a valuable tool to investigate the cortical landscape and its (mal-)adaptive plasticity with respect to various body part representations, in particular extremities such as the hand and fingers. Less is known, however, about the cortical representation of the human back. We therefore validated a novel, MRI-compatible method of mapping cortical representations of sensory afferents of the back, using vibrotactile stimulation at varying frequencies and paraspinal locations, in conjunction with fMRI. We expected high-frequency stimulation to be associated with differential neuronal activity in the primary somatosensory cortex (S1) compared with low-frequency stimulation and that somatosensory representations would differ across the thoracolumbar axis. We found significant differences between neural representations of high-frequency and low-frequency stimulation and between representations of thoracic and lumbar paraspinal locations, in several bilateral S1 sub-regions, and in regions of the primary motor cortex (M1). High-frequency stimulation preferentially activated Brodmann Area (BA) regions BA3a and BA4p, whereas low-frequency stimulation was more encoded in BA3b and BA4a. Moreover, we found clear topographic differences in S1 for representations of the upper and lower back during high-frequency stimulation. We present the first neurobiological validation of a method for establishing detailed cortical maps of the human back, which might serve as a novel tool to evaluate the pathological significance of neuroplastic changes in clinical conditions such as chronic low back pain.
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Affiliation(s)
- David M Cole
- Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.,Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland
| | - Philipp Stämpfli
- Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland.,MR-Center of the Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Robert Gandia
- Competence Center Thermal Energy Storage, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland
| | - Louis Schibli
- Competence Center Thermal Energy Storage, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland
| | - Sandro Gantner
- Competence Center Thermal Energy Storage, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland
| | - Philipp Schuetz
- Competence Center Thermal Energy Storage, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland
| | - Michael L Meier
- Integrative Spinal Research, Department of Chiropractic Medicine, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
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16
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Janko D, Thoenes K, Park D, Willoughby WR, Horton M, Bolding M. Somatotopic Mapping of the Fingers in the Somatosensory Cortex Using Functional Magnetic Resonance Imaging: A Review of Literature. Front Neuroanat 2022; 16:866848. [PMID: 35847829 PMCID: PMC9277538 DOI: 10.3389/fnana.2022.866848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/16/2022] [Indexed: 11/29/2022] Open
Abstract
Multiple studies have demonstrated finger somatotopy in humans and other primates using a variety of brain mapping techniques including functional magnetic resonance imaging (fMRI). Here, we review the literature to better understand the reliability of fMRI for mapping the somatosensory cortex. We have chosen to focus on the hand and fingers as these areas have the largest representation and have been the subject of the largest number of somatotopic mapping experiments. Regardless of the methods used, individual finger somatosensory maps were found to be organized across Brodmann areas (BAs) 3b, 1, and 2 in lateral-to-medial and inferior-to-superior fashion moving from the thumb to the pinky. However, some consistent discrepancies are found that depend principally on the method used to stimulate the hand and fingers. Therefore, we suggest that a comparative analysis of different types of stimulation be performed to address the differences described in this review.
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Affiliation(s)
- Daniel Janko
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Kristina Thoenes
- Edward Via College of Osteopathic Medicine Auburn, Auburn, AL, United States
| | - Dahye Park
- School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - W. R. Willoughby
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Meredith Horton
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mark Bolding
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL, United States
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17
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Oda H, Tsujinaka R, Fukuda S, Sawaguchi Y, Hiraoka K. Tactile perception of right middle fingertip suppresses excitability of motor cortex supplying right first dorsal interosseous muscle. Neuroscience 2022; 494:82-93. [PMID: 35588919 DOI: 10.1016/j.neuroscience.2022.05.012] [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: 01/20/2022] [Revised: 05/08/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022]
Abstract
The present study examined whether tactile perception of the fingertip modulates excitability of the motor cortex supplying the intrinsic hand muscle and whether this modulation is specific to the fingertip stimulated and the muscle and hand tested. Tactile stimulation was given to one of the five fingertips in the left or right hand, and transcranial magnetic stimulation eliciting motor evoked potential in the first dorsal interosseous muscle (FDI) or abductor digiti minimi was given 200 ms after the onset of tactile stimulation. The corticospinal excitability of the FDI at rest was suppressed by the tactile stimulation of the right middle fingertip, but such suppression was absent for the other fingers stimulated and for the other muscle or hand tested. The persistence and amplitude of the F-wave was not significantly influenced by tactile stimulation of the fingertip in the right hand. These findings indicate that tactile perception of the right middle fingertip suppresses excitability of the motor cortex supplying the right FDI at rest. The suppression of corticospinal excitability was absent during tonic contraction of the right FDI, indicating that the motor execution process interrupts the tactile perception-induced suppression of motor cortical excitability supplying the right FDI. These findings are in line with a view that the tactile perception of the right middle finger induces surround inhibition of the motor cortex supplying the prime mover of the finger neighboring the stimulated finger.
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Affiliation(s)
- Hitoshi Oda
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Ryo Tsujinaka
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Shiho Fukuda
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Yasushi Sawaguchi
- Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino city, Osaka, Japan
| | - Koichi Hiraoka
- College of Health and Human Sciences, Osaka Prefecture University, Habikino city, Osaka, Japan.
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18
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Wesselink DB, Sanders ZB, Edmondson LR, Dempsey-Jones H, Kieliba P, Kikkert S, Themistocleous AC, Emir U, Diedrichsen J, Saal HP, Makin TR. Malleability of the cortical hand map following a finger nerve block. SCIENCE ADVANCES 2022; 8:eabk2393. [PMID: 35452294 PMCID: PMC9032959 DOI: 10.1126/sciadv.abk2393] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Electrophysiological studies in monkeys show that finger amputation triggers local remapping within the deprived primary somatosensory cortex (S1). Human neuroimaging research, however, shows persistent S1 representation of the missing hand's fingers, even decades after amputation. Here, we explore whether this apparent contradiction stems from underestimating the distributed peripheral and central representation of fingers in the hand map. Using pharmacological single-finger nerve block and 7-tesla neuroimaging, we first replicated previous accounts (electrophysiological and other) of local S1 remapping. Local blocking also triggered activity changes to nonblocked fingers across the entire hand area. Using methods exploiting interfinger representational overlap, however, we also show that the blocked finger representation remained persistent despite input loss. Computational modeling suggests that both local stability and global reorganization are driven by distributed processing underlying the topographic map, combined with homeostatic mechanisms. Our findings reveal complex interfinger representational features that play a key role in brain (re)organization, beyond (re)mapping.
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Affiliation(s)
- Daan B. Wesselink
- Institute of Cognitive Neuroscience, University College London, London, UK
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Corresponding author.
| | - Zeena-Britt Sanders
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Laura R. Edmondson
- Active Touch Laboratory, Department of Psychology, The University of Sheffield, Sheffield, UK
| | - Harriet Dempsey-Jones
- Institute of Cognitive Neuroscience, University College London, London, UK
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
- School of Psychology, University of Queensland, Brisbane, Australia
| | - Paulina Kieliba
- Institute of Cognitive Neuroscience, University College London, London, UK
| | - Sanne Kikkert
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Andreas C. Themistocleous
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Brain Function Research Group, University of the Witwatersrand, Johannesburg, South Africa
| | - Uzay Emir
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Jörn Diedrichsen
- Brain and Mind Institute, University of Western Ontario, London, Canada
| | - Hannes P. Saal
- Active Touch Laboratory, Department of Psychology, The University of Sheffield, Sheffield, UK
| | - Tamar R. Makin
- Institute of Cognitive Neuroscience, University College London, London, UK
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
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19
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Jaatela J, Aydogan DB, Nurmi T, Vallinoja J, Piitulainen H. Identification of Proprioceptive Thalamocortical Tracts in Children: Comparison of fMRI, MEG, and Manual Seeding of Probabilistic Tractography. Cereb Cortex 2022; 32:3736-3751. [PMID: 35040948 PMCID: PMC9433422 DOI: 10.1093/cercor/bhab444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 11/16/2022] Open
Abstract
Studying white matter connections with tractography is a promising approach to understand the development of different brain processes, such as proprioception. An emerging method is to use functional brain imaging to select the cortical seed points for tractography, which is considered to improve the functional relevance and validity of the studied connections. However, it is unknown whether different functional seeding methods affect the spatial and microstructural properties of the given white matter connection. Here, we compared functional magnetic resonance imaging, magnetoencephalography, and manual seeding of thalamocortical proprioceptive tracts for finger and ankle joints separately. We showed that all three seeding approaches resulted in robust thalamocortical tracts, even though there were significant differences in localization of the respective proprioceptive seed areas in the sensorimotor cortex, and in the microstructural properties of the obtained tracts. Our study shows that the selected functional or manual seeding approach might cause systematic biases to the studied thalamocortical tracts. This result may indicate that the obtained tracts represent different portions and features of the somatosensory system. Our findings highlight the challenges of studying proprioception in the developing brain and illustrate the need for using multimodal imaging to obtain a comprehensive view of the studied brain process.
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Affiliation(s)
- Julia Jaatela
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo FI-02150, Finland
| | - Dogu Baran Aydogan
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo FI-02150, Finland
- Department of Psychiatry, Helsinki University Hospital, Helsinki FI-00029, Finland
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio FI-70211, Finland
| | - Timo Nurmi
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo FI-02150, Finland
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä FI-40014, Finland
| | - Jaakko Vallinoja
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo FI-02150, Finland
| | - Harri Piitulainen
- Address correspondence to Harri Piitulainen, associate professor, Harri Piitulainen, Faculty of Sport and Health Sciences, University of Jyväskylä, P.O. BOX 35, FI-40014, Finland.
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20
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Gooijers J, Chalavi S, Koster LK, Roebroeck A, Kaas A, Swinnen SP. Representational Similarity Scores of Digits in the Sensorimotor Cortex Are Associated with Behavioral Performance. Cereb Cortex 2022; 32:3848-3863. [PMID: 35029640 DOI: 10.1093/cercor/bhab452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 02/06/2023] Open
Abstract
Previous studies aimed to unravel a digit-specific somatotopy in the primary sensorimotor (SM1) cortex. However, it remains unknown whether digit somatotopy is associated with motor preparation and/or motor execution during different types of tasks. We adopted multivariate representational similarity analysis to explore digit activation patterns in response to a finger tapping task (FTT). Sixteen healthy young adults underwent magnetic resonance imaging, and additionally performed an out-of-scanner choice reaction time task (CRTT) to assess digit selection performance. During both the FTT and CRTT, force data of all digits were acquired using force transducers. This allowed us to assess execution-related interference (i.e., digit enslavement; obtained from FTT & CRTT), as well as planning-related interference (i.e., digit selection deficit; obtained from CRTT) and determine their correlation with digit representational similarity scores of SM1. Findings revealed that digit enslavement during FTT was associated with contralateral SM1 representational similarity scores. During the CRTT, digit enslavement of both hands was also associated with representational similarity scores of the contralateral SM1. In addition, right hand digit selection performance was associated with representational similarity scores of left S1. In conclusion, we demonstrate a cortical origin of digit enslavement, and uniquely reveal that digit selection is associated with digit representations in primary somatosensory cortex (S1). Significance statement In current systems neuroscience, it is of critical importance to understand the relationship between brain function and behavioral outcome. With the present work, we contribute significantly to this understanding by uniquely assessing how digit representations in the sensorimotor cortex are associated with planning- and execution-related digit interference during a continuous finger tapping and a choice reaction time task. We observe that digit enslavement (i.e., execution-related interference) finds its origin in contralateral digit representations of SM1, and that deficits in digit selection (i.e., planning-related interference) in the right hand during a choice reaction time task are associated with more overlapping digit representations in left S1. This knowledge sheds new light on the functional contribution of the sensorimotor cortex to everyday motor skills.
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Affiliation(s)
- J Gooijers
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven 3000, Belgium
- LBI-KU Leuven Brain Institute, Leuven 3000, Belgium
| | - S Chalavi
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven 3000, Belgium
- LBI-KU Leuven Brain Institute, Leuven 3000, Belgium
| | - L K Koster
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven 3000, Belgium
| | - A Roebroeck
- Department of Cognitive Neuroscience, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht 6229 EV, the Netherlands
| | - A Kaas
- Department of Cognitive Neuroscience, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht 6229 EV, the Netherlands
| | - S P Swinnen
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven 3000, Belgium
- LBI-KU Leuven Brain Institute, Leuven 3000, Belgium
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21
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Zlatkina V, Sprung-Much T, Petrides M. Spatial probability maps of the segments of the postcentral sulcus in the human brain. Cereb Cortex 2021; 32:3651-3668. [PMID: 34963136 PMCID: PMC9433426 DOI: 10.1093/cercor/bhab439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 12/31/2022] Open
Abstract
The postcentral sulcus is the posterior boundary of the postcentral gyrus where the somatosensory cortex is represented. In the human brain, the postcentral sulcus is composed of five distinct segments that are related to the somatosensory representation of different parts of the body. Segment 1 of the postcentral sulcus, located near the dorsomedial boundary of each hemisphere, is associated with toe/leg representations, segment 2 with arm/hand representations, segment 3 with blinking, and segments 4 and 5, which are near the lateral fissure and the parietal operculum, with the mouth and tongue representations. The variability in location and spatial extent of these five segments were quantified in 40 magnetic resonance imaging (MRI) anatomical brain scans registered to the stereotaxic space of the Montreal Neurological Institute (MNI space), in the form of volumetric (using MINC Toolkit) and surface (using FreeSurfer) spatial probability maps. These probability maps can be used by researchers and clinicians to improve the localization of the segments of the postcentral sulcus in MRI images of interest and also to improve the interpretation of the location of activation peaks generated in functional neuroimaging studies investigating somatosensory cortex.
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Affiliation(s)
- Veronika Zlatkina
- Address correspondence to Veronika Zlatkina, Montreal Neurological Institute, 3801 University St., Montreal, QC H3A 2B4, Canada.
| | - Trisanna Sprung-Much
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | - Michael Petrides
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
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22
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McMullen DP, Thomas TM, Fifer MS, Candrea DN, Tenore FV, Nickl RW, Pohlmeyer EA, Coogan C, Osborn LE, Schiavi A, Wojtasiewicz T, Gordon CR, Cohen AB, Ramsey NF, Schellekens W, Bensmaia SJ, Cantarero GL, Celnik PA, Wester BA, Anderson WS, Crone NE. Novel intraoperative online functional mapping of somatosensory finger representations for targeted stimulating electrode placement: technical note. J Neurosurg 2021; 135:1493-1500. [PMID: 33770760 DOI: 10.3171/2020.9.jns202675] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/29/2020] [Indexed: 11/06/2022]
Abstract
Defining eloquent cortex intraoperatively, traditionally performed by neurosurgeons to preserve patient function, can now help target electrode implantation for restoring function. Brain-machine interfaces (BMIs) have the potential to restore upper-limb motor control to paralyzed patients but require accurate placement of recording and stimulating electrodes to enable functional control of a prosthetic limb. Beyond motor decoding from recording arrays, precise placement of stimulating electrodes in cortical areas associated with finger and fingertip sensations allows for the delivery of sensory feedback that could improve dexterous control of prosthetic hands. In this study, the authors demonstrated the use of a novel intraoperative online functional mapping (OFM) technique with high-density electrocorticography to localize finger representations in human primary somatosensory cortex. In conjunction with traditional pre- and intraoperative targeting approaches, this technique enabled accurate implantation of stimulating microelectrodes, which was confirmed by postimplantation intracortical stimulation of finger and fingertip sensations. This work demonstrates the utility of intraoperative OFM and will inform future studies of closed-loop BMIs in humans.
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Affiliation(s)
- David P McMullen
- 1National Institute of Mental Health, National Institutes of Health, Bethesda
| | | | - Matthew S Fifer
- 3Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland
| | | | - Francesco V Tenore
- 3Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland
| | | | - Eric A Pohlmeyer
- 3Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland
| | | | - Luke E Osborn
- 3Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland
| | | | | | - Chad R Gordon
- 8Plastic and Reconstructive Surgery, Johns Hopkins University, Baltimore
| | - Adam B Cohen
- 3Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland
- 5Neurology
| | - Nick F Ramsey
- 9UMC Utrecht Brain Center, Utrecht, The Netherlands; and
| | | | - Sliman J Bensmaia
- 10Department of Organismal Biology and Anatomy, University of Chicago, Illinois
| | | | | | - Brock A Wester
- 3Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland
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23
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Kikkert S, Pfyffer D, Verling M, Freund P, Wenderoth N. Finger somatotopy is preserved after tetraplegia but deteriorates over time. eLife 2021; 10:e67713. [PMID: 34665133 PMCID: PMC8575460 DOI: 10.7554/elife.67713] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 10/18/2021] [Indexed: 12/12/2022] Open
Abstract
Previous studies showed reorganised and/or altered activity in the primary sensorimotor cortex after a spinal cord injury (SCI), suggested to reflect abnormal processing. However, little is known about whether somatotopically specific representations can be activated despite reduced or absent afferent hand inputs. In this observational study, we used functional MRI and a (attempted) finger movement task in tetraplegic patients to characterise the somatotopic hand layout in primary somatosensory cortex. We further used structural MRI to assess spared spinal tissue bridges. We found that somatotopic hand representations can be activated through attempted finger movements in the absence of sensory and motor hand functioning, and no spared spinal tissue bridges. Such preserved hand somatotopy could be exploited by rehabilitation approaches that aim to establish new hand-brain functional connections after SCI (e.g. neuroprosthetics). However, over years since SCI the hand representation somatotopy deteriorated, suggesting that somatotopic hand representations are more easily targeted within the first years after SCI.
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Affiliation(s)
- Sanne Kikkert
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, ETH ZürichZürichSwitzerland
- Spinal Cord Injury Center, Balgrist University Hospital, University of ZürichZürichSwitzerland
| | - Dario Pfyffer
- Spinal Cord Injury Center, Balgrist University Hospital, University of ZürichZürichSwitzerland
| | - Michaela Verling
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, ETH ZürichZürichSwitzerland
| | - Patrick Freund
- Spinal Cord Injury Center, Balgrist University Hospital, University of ZürichZürichSwitzerland
- Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, University College LondonLondonUnited Kingdom
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College LondonLondonUnited Kingdom
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain SciencesLeipzigGermany
| | - Nicole Wenderoth
- Neural Control of Movement Laboratory, Department of Health Sciences and Technology, ETH ZürichZürichSwitzerland
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24
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Wang L, Zhang Z, Okada T, Li C, Chen D, Funahashi S, Wu J, Yan T. Population Receptive Field Characteristics in the between- and Within-Digit Dimensions of the Undominant Hand in the Primary Somatosensory Cortex. Cereb Cortex 2021; 31:4427-4438. [PMID: 33973012 PMCID: PMC8408438 DOI: 10.1093/cercor/bhab097] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/02/2021] [Accepted: 03/20/2021] [Indexed: 11/13/2022] Open
Abstract
Somatotopy is an important guiding principle for sensory fiber organization in the primary somatosensory cortex (S1), which reflects tactile information processing and is associated with disease-related reorganization. However, it is difficult to measure the neuronal encoding scheme in S1 in vivo in normal participants. Here, we investigated the somatotopic map of the undominant hand using a Bayesian population receptive field (pRF) model. The model was established in hand space with between- and within-digit dimensions. In the between-digit dimension, orderly representation was found, which had low variability across participants. The pRF shape tended to be elliptical for digits with high spatial acuity, for which the long axis was along the within-digit dimension. In addition, the pRF width showed different change trends in the 2 dimensions across digits. These results provide new insights into the neural mechanisms in S1, allowing for in-depth investigation of somatosensory information processing and disease-related reorganization.
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Affiliation(s)
- Luyao Wang
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China.,Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Zhilin Zhang
- Department of Psychiatry, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Tomohisa Okada
- Human Brain Research Center, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Chunlin Li
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, China
| | - Duanduan Chen
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Shintaro Funahashi
- Advanced research institute of multidisciplinary science, Beijing Institute of Technology, Beijing 100081, China
| | - Jinglong Wu
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Tianyi Yan
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
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25
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Chandrasekaran S, Bickel S, Herrero JL, Kim JW, Markowitz N, Espinal E, Bhagat NA, Ramdeo R, Xu J, Glasser MF, Bouton CE, Mehta AD. Evoking highly focal percepts in the fingertips through targeted stimulation of sulcal regions of the brain for sensory restoration. Brain Stimul 2021; 14:1184-1196. [PMID: 34358704 PMCID: PMC8884403 DOI: 10.1016/j.brs.2021.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 06/29/2021] [Accepted: 07/19/2021] [Indexed: 01/06/2023] Open
Abstract
Background: Paralysis and neuropathy, affecting millions of people worldwide, can be accompanied by significant loss of somatosensation. With tactile sensation being central to achieving dexterous movement, brain-computer interface (BCI) researchers have used intracortical and cortical surface electrical stimulation to restore somatotopically-relevant sensation to the hand. However, these approaches are restricted to stimulating the gyral areas of the brain. Since representation of distal regions of the hand extends into the sulcal regions of human primary somatosensory cortex (S1), it has been challenging to evoke sensory percepts localized to the fingertips. Objective/hypothesis: Targeted stimulation of sulcal regions of S1, using stereoelectroencephalography (SEEG) depth electrodes, can evoke focal sensory percepts in the fingertips. Methods: Two participants with intractable epilepsy received cortical stimulation both at the gyri via high-density electrocorticography (HD-ECoG) grids and in the sulci via SEEG depth electrode leads. We characterized the evoked sensory percepts localized to the hand. Results: We show that highly focal percepts can be evoked in the fingertips of the hand through sulcal stimulation. fMRI, myelin content, and cortical thickness maps from the Human Connectome Project elucidated specific cortical areas and sub-regions within S1 that evoked these focal percepts. Within-participant comparisons showed that percepts evoked by sulcal stimulation via SEEG electrodes were significantly more focal (80% less area; p = 0.02) and localized to the fingertips more often, than by gyral stimulation via HD-ECoG electrodes. Finally, sulcal locations with consistent modulation of high-frequency neural activity during mechanical tactile stimulation of the fingertips showed the same somatotopic correspondence as cortical stimulation. Conclusions: Our findings indicate minimally invasive sulcal stimulation via SEEG electrodes could be a clinically viable approach to restoring sensation.
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Affiliation(s)
- Santosh Chandrasekaran
- Neural Bypass and Brain Computer Interface Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA.
| | - Stephan Bickel
- The Human Brain Mapping Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA; Department of Neurosurgery, Northwell, Manhasset, NY, USA; Department of Neurology, Donald and Barbara Zucker School of Medicine at Hofstra, Northwell, Manhasset, NY, USA
| | - Jose L Herrero
- The Human Brain Mapping Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA; Department of Neurosurgery, Northwell, Manhasset, NY, USA
| | - Joo-Won Kim
- Departments of Radiology and Psychiatry, Baylor College of Medicine, Houston, TX, USA
| | - Noah Markowitz
- The Human Brain Mapping Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA
| | - Elizabeth Espinal
- The Human Brain Mapping Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA
| | - Nikunj A Bhagat
- Neural Bypass and Brain Computer Interface Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA
| | - Richard Ramdeo
- Neural Bypass and Brain Computer Interface Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA
| | - Junqian Xu
- Departments of Radiology and Psychiatry, Baylor College of Medicine, Houston, TX, USA
| | - Matthew F Glasser
- Departments of Radiology and Neuroscience, Washington University in St Louis, Saint Louis, MO, USA
| | - Chad E Bouton
- Neural Bypass and Brain Computer Interface Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA; Department of Molecular Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Manhasset, NY, USA.
| | - Ashesh D Mehta
- The Human Brain Mapping Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA; Department of Neurosurgery, Northwell, Manhasset, NY, USA
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26
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Temporal Dynamics of Brain White Matter Plasticity in Sighted Subjects during Tactile Braille Learning: A Longitudinal Diffusion Tensor Imaging Study. J Neurosci 2021; 41:7076-7085. [PMID: 34253624 DOI: 10.1523/jneurosci.2242-20.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 05/05/2021] [Accepted: 06/08/2021] [Indexed: 12/26/2022] Open
Abstract
The white matter (WM) architecture of the human brain changes in response to training, though fine-grained temporal characteristics of training-induced white matter plasticity remain unexplored. We investigated white matter microstructural changes using diffusion tensor imaging at five different time points in 26 sighted female adults during 8 months of training on tactile braille reading. Our results show that training-induced white matter plasticity occurs both within and beyond the trained sensory modality, as reflected by fractional anisotropy (FA) increases in somatosensory and visual cortex, respectively. The observed changes followed distinct time courses, with gradual linear FA increase along the training in the somatosensory cortex and sudden visual cortex cross-modal plasticity occurring after braille input became linguistically meaningful. WM changes observed in these areas returned to baseline after the cessation of learning in line with the supply-demand model of plasticity. These results also indicate that the temporal dynamics of microstructural plasticity in different cortical regions might be modulated by the nature of computational demands. We provide additional evidence that observed FA training-induced changes are behaviorally relevant to tactile reading. Together, these results demonstrate that WM plasticity is a highly dynamic process modulated by the introduction of novel experiences.SIGNIFICANCE STATEMENT Throughout the lifetime the human brain is shaped by various experiences. Training-induced reorganization in white matter (WM) microstructure has been reported, but we know little about its temporal dynamics. To fill this gap, we scanned sighted subjects five times during tactile braille reading training. We observed different dynamics of WM plasticity in the somatosensory and visual cortices implicated in braille reading. The former showed a continuous increase in WM tissue anisotropy along with tactile training, while microstructural changes in the latter were observed only after the participants learned to read braille words. Our results confirm the supply-demand model of brain plasticity and provide evidence that WM reorganization depends on distinct computational demands and functional roles of regions involved in the trained skill.
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27
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Abstract
Perception of distance between two touches varies with orientation on the hand, with distances aligned with hand width perceived as larger than those aligned with hand length. Similar anisotropies are found on other body parts (e.g., the face), suggesting they may reflect a general feature of tactile organization, but appear absent on other body parts (e.g., the belly). Here, we investigated tactile-distance anisotropy on the foot, a body part structurally and embryologically similar to the hand, but with very different patterns of functional usage in humans. In three experiments, we compared the perceived distance between pairs of touches aligned with the medio-lateral and proximal-distal foot axes. On the hairy skin of the foot dorsum, anisotropy was consistently found, with distances aligned with the medio-lateral foot axis perceived as larger than those in the proximo-distal axis. In contrast, on the glabrous skin of the sole, inconsistent results were found across experiments, with no overall evidence for anisotropy. This shows a pattern of anisotropy on the foot broadly similar to that on the hand, adding to the list of body parts showing tactile-distance anisotropy, and providing further evidence that such biases are a general aspect of tactile spatial organization across the body. Significance: The perception of tactile distance has been widely used to understand the spatial structure of touch. On the hand, anisotropy of tactile distance perception is well established, with distances oriented across hand width perceived larger than those oriented along hand length. We investigated tactile-distance anisotropy on the feet, a body part structurally, genetically, and developmentally homologous to the hands, but with strikingly different patterns of functional usage. We report highly similar patterns of anisotropy on the hairy skin of the hand dorsum and foot dorsum. This suggests that anisotropy arises from the general organization of touch across the body.
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28
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Schellekens W, Thio M, Badde S, Winawer J, Ramsey N, Petridou N. A touch of hierarchy: population receptive fields reveal fingertip integration in Brodmann areas in human primary somatosensory cortex. Brain Struct Funct 2021; 226:2099-2112. [PMID: 34091731 PMCID: PMC8354965 DOI: 10.1007/s00429-021-02309-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 05/26/2021] [Indexed: 12/03/2022]
Abstract
Several neuroimaging studies have shown the somatotopy of body part representations in primary somatosensory cortex (S1), but the functional hierarchy of distinct subregions in human S1 has not been adequately addressed. The current study investigates the functional hierarchy of cyto-architectonically distinct regions, Brodmann areas BA3, BA1, and BA2, in human S1. During functional MRI experiments, we presented participants with vibrotactile stimulation of the fingertips at three different vibration frequencies. Using population Receptive Field (pRF) modeling of the fMRI BOLD activity, we identified the hand region in S1 and the somatotopy of the fingertips. For each voxel, the pRF center indicates the finger that most effectively drives the BOLD signal, and the pRF size measures the spatial somatic pooling of fingertips. We find a systematic relationship of pRF sizes from lower-order areas to higher-order areas. Specifically, we found that pRF sizes are smallest in BA3, increase slightly towards BA1, and are largest in BA2, paralleling the increase in visual receptive field size as one ascends the visual hierarchy. Additionally, we find that the time-to-peak of the hemodynamic response in BA3 is roughly 0.5 s earlier compared to BA1 and BA2, further supporting the notion of a functional hierarchy of subregions in S1. These results were obtained during stimulation of different mechanoreceptors, suggesting that different afferent fibers leading up to S1 feed into the same cortical hierarchy.
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Affiliation(s)
- W Schellekens
- Department of Radiology, Center for Image Sciences, UMC Utrecht, Q101.132, P.O.Box 85500, 3508 GA, Utrecht, The Netherlands.
| | - M Thio
- Department of Radiology, Center for Image Sciences, UMC Utrecht, Q101.132, P.O.Box 85500, 3508 GA, Utrecht, The Netherlands
| | - S Badde
- Department of Psychology and Center of Neural Science, NYU, New York, USA
| | - J Winawer
- Department of Psychology and Center of Neural Science, NYU, New York, USA
| | - N Ramsey
- Department of Neurology and Neurosurgery, UMC Utrecht, Utrecht, The Netherlands
| | - N Petridou
- Department of Radiology, Center for Image Sciences, UMC Utrecht, Q101.132, P.O.Box 85500, 3508 GA, Utrecht, The Netherlands
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29
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Beier F, Löffler M, Nees F, Hausner L, Frölich L, Flor H. Promoting neuroplasticity and neuropsychological functioning in frailty through an app-based sensorimotor training: study protocol for a randomized trial. BMC Geriatr 2021; 21:343. [PMID: 34082710 PMCID: PMC8173957 DOI: 10.1186/s12877-021-02293-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 05/20/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Frailty is characterized by an age-related decline in multiple physiological systems, leading to a high vulnerability to stressors, adverse health outcomes, and low quality of life. Neuroscientific models of pathological aging emphasize the loss of sensorimotor stimulation and reduced neuromodulatory capacities as core processes in age-related cognitive and bodily decline, which may be associated with maladaptive plastic changes in the brain. We plan to increase sensorimotor stimulation in frail persons through a newly developed app-based training program and link the training trials to biological and psychological correlates of age-associated vulnerability and health indices. METHODS We will conduct a randomized trial, applying an app-based sensorimotor home training (N = 30) in people suffering from frailty. An app-based relaxation training will serve as an active control condition (N = 30). Both interventions will last for 90 days each. The sensorimotor training includes unimodal and multimodal sensory discrimination tasks in the visual, auditory, and tactile domain, as well as sensorimotor precision tasks. The tasks will be implemented using an adaptive training algorithm and enriched with motivational components embedded in a virtual training environment. We expect a pre-post reduction of frailty status and associated functional decline related to refinement of representational maps within the sensorimotor system and improved sensorimotor function such as extremity function. Secondary analyses will study the influence of BDNF genotype as moderating variable. Additional outcomes will include measures of perceptual and cognitive functioning, quality of life as well as BDNF serum levels. Measurements will take place before training (baseline), after 60 days (assessment 1), and at the end of the training after 90 days (assessment 2). DISCUSSION In our randomized trial, we aim to characterize a multidimensional concept of frailty and to target maladaptive behaviors and neuroplasticity using an app-based sensorimotor training. This type of intervention might provide further knowledge and new possibilities for preventing decline and preserving function in older adults. TRIAL REGISTRATION ClinicalTrials.gov NCT03666039 . Registered 11 September 2018 - Retrospectively registered. Protocol version: Version 4 revised (issue date: 19 May 2021).
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Affiliation(s)
- Florian Beier
- Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159, Mannheim, Germany
| | - Martin Löffler
- Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159, Mannheim, Germany
| | - Frauke Nees
- Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159, Mannheim, Germany
- Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig-Holstein, Kiel University, Kiel, Germany
| | - Lucrezia Hausner
- Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159, Mannheim, Germany
- Department of Geriatric Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lutz Frölich
- Department of Geriatric Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Herta Flor
- Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159, Mannheim, Germany.
- Department of Psychology, School of Social Sciences, University of Mannheim, Mannheim, Germany.
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30
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Liu P, Chrysidou A, Doehler J, Hebart MN, Wolbers T, Kuehn E. The organizational principles of de-differentiated topographic maps in somatosensory cortex. eLife 2021; 10:e60090. [PMID: 34003108 PMCID: PMC8186903 DOI: 10.7554/elife.60090] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 05/17/2021] [Indexed: 01/09/2023] Open
Abstract
Topographic maps are a fundamental feature of cortex architecture in the mammalian brain. One common theory is that the de-differentiation of topographic maps links to impairments in everyday behavior due to less precise functional map readouts. Here, we tested this theory by characterizing de-differentiated topographic maps in primary somatosensory cortex (SI) of younger and older adults by means of ultra-high resolution functional magnetic resonance imaging together with perceptual finger individuation and hand motor performance. Older adults' SI maps showed similar amplitude and size to younger adults' maps, but presented with less representational similarity between distant fingers. Larger population receptive field sizes in older adults' maps did not correlate with behavior, whereas reduced cortical distances between D2 and D3 related to worse finger individuation but better motor performance. Our data uncover the drawbacks of a simple de-differentiation model of topographic map function, and motivate the introduction of feature-based models of cortical reorganization.
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Affiliation(s)
- Peng Liu
- Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University MagdeburgMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Anastasia Chrysidou
- Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University MagdeburgMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Juliane Doehler
- Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University MagdeburgMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Martin N Hebart
- Vision and Computational Cognition Group, Max Planck Institute for Human Cognitive and Brain SciencesLeipzigGermany
| | - Thomas Wolbers
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
- Center for Behavioral Brain Sciences (CBBS) MagdeburgMagdeburgGermany
| | - Esther Kuehn
- Institute for Cognitive Neurology and Dementia Research (IKND), Otto-von-Guericke University MagdeburgMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
- Center for Behavioral Brain Sciences (CBBS) MagdeburgMagdeburgGermany
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31
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Sun F, Zhang G, Yu T, Zhang X, Wang X, Yan X, Qiao L, Ma K, Zhang X. Functional characteristics of the human primary somatosensory cortex: An electrostimulation study. Epilepsy Behav 2021; 118:107920. [PMID: 33770611 DOI: 10.1016/j.yebeh.2021.107920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/01/2021] [Accepted: 03/02/2021] [Indexed: 10/21/2022]
Abstract
The common knowledge of the functional organization of the human primary somatosensory cortex (S1) had been primarily established by Penfield who electrically stimulated the exposed surface [referred as Brodmann area (BA)1] of S1 under neurosurgical conditions. Nevertheless, the functional information regarding the deep surface (BA 2 and 3) of S1 is poorly understood. We retrospectively analyzed all the clinical manifestations induced by extra-operative cortical electrical stimulation (ES) in 33 patients with medically intractable epilepsy who underwent stereo-electroencephalography (SEEG) monitoring for presurgical assessment. Demographic and clinical data were gathered and evaluated to delineate the determinants of the occurrence of positive responses, types of responses, and size of body regions involved. The stimulation of 244 sites in S1 yielded 198 positive sites (81.1%), most of which were located in the sulcal cortex. In multivariable analyses, no clinical or demographic factors predicted the occurrence of responses or their threshold levels. The size of body region involved in the responses had ordinal association with the stimulated BA sites (p < 0.001). Various types of responses elicited from the S1 were documented and classified, and the predictors of those responses were also assessed. Our analysis revealed the functional characteristics of the entire S1 and proved the multiplicity of functions of S1.
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Affiliation(s)
- Fengqiao Sun
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Guojun Zhang
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China.
| | - Tao Yu
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Xiaohua Zhang
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Xueyuan Wang
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Xiaoming Yan
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Liang Qiao
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Kai Ma
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Xi Zhang
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
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Oblak E, Lewis-Peacock J, Sulzer J. Differential neural plasticity of individual fingers revealed by fMRI neurofeedback. J Neurophysiol 2021; 125:1720-1734. [PMID: 33788634 DOI: 10.1152/jn.00509.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Previous work has shown that functional magnetic resonance imaging (fMRI) activity patterns associated with individual fingers can be shifted by temporary impairment of the hand. Here, we investigated whether these neural activity patterns could be modulated endogenously and whether any behavioral changes result from this modulation. We used decoded neurofeedback in healthy individuals to encourage participants to shift the neural activity pattern in sensorimotor cortex of the middle finger toward the index finger, and the ring finger toward the little finger. We first mapped the neural activity patterns for all fingers of the right hand in an fMRI pattern localizer session. Then, in three subsequent neurofeedback sessions, participants were rewarded after middle/ring finger presses according to their activity pattern overlap during each trial. A force-sensitive keyboard was used to ensure that participants were not altering their physical finger coordination patterns. We found evidence that participants could learn to shift the activity pattern of the ring finger but not of the middle finger. Increased variability of these activity patterns during the localizer session was associated with the ability of participants to modulate them using neurofeedback. Participants also showed an increased preference for the ring finger but not for the middle finger in a postneurofeedback motor task. Our results show that neural activity and behaviors associated with the ring finger are more readily modulated than those associated with the middle finger. These results have broader implications for rehabilitation of individual finger movements, which may be limited or enhanced by individual finger plasticity after neurological injury.NEW & NOTEWORTHY It may be possible to remobilize fingers after neurological injury by altering neural activity patterns. Toward this end, we examined whether finger-related neural activity patterns could be modified in healthy individuals without physical intervention, using fMRI neurofeedback. Our findings show that greater variability of neural patterns at baseline predicted a participant's ability to successfully shift these patterns. Because neural variability is common in individuals poststroke, this illustrates a potential clinical benefit of this procedure.
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Affiliation(s)
- Ethan Oblak
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas
| | | | - James Sulzer
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas
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Kaiju T, Inoue M, Hirata M, Suzuki T. High-density mapping of primate digit representations with a 1152-channel µECoG array. J Neural Eng 2021; 18. [PMID: 33530064 DOI: 10.1088/1741-2552/abe245] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/02/2021] [Indexed: 12/11/2022]
Abstract
Objective.Advances in brain-machine interfaces (BMIs) are expected to support patients with movement disorders. Electrocorticogram (ECoG) measures electrophysiological activities over a large area using a low-invasive flexible sheet placed on the cortex. ECoG has been considered as a feasible signal source of the clinical BMI device. To capture neural activities more precisely, the feasibility of higher-density arrays has been investigated. However, currently, the number of electrodes is limited to approximately 300 due to wiring difficulties, device size, and system costs.Approach.We developed a high-density recording system with a large coverage (14 × 7 mm2) and using 1152 electrodes by directly integrating dedicated flexible arrays with the neural-recording application-specific integrated circuits and their interposers.Main results.Comparative experiments with a 128-channel array demonstrated that the proposed device could delineate the entire digit representation of a nonhuman primate. Subsampling analysis revealed that higher-amplitude signals can be measured using higher-density arrays.Significance.We expect that the proposed system that simultaneously establishes large-scale sampling, high temporal-precision of electrophysiology, and high spatial resolution comparable to optical imaging will be suitable for next-generation brain-sensing technology.
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Affiliation(s)
- Taro Kaiju
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan
| | - Masato Inoue
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan.,Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Masayuki Hirata
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Osaka, Japan.,Department of Neurological Diagnosis and Restoration, Osaka University Graduate School of Medicine, Osaka, Japan
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Sun F, Zhang G, Ren L, Yu T, Ren Z, Gao R, Zhang X. Functional organization of the human primary somatosensory cortex: A stereo-electroencephalography study. Clin Neurophysiol 2021; 132:487-497. [PMID: 33465535 DOI: 10.1016/j.clinph.2020.11.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/31/2020] [Accepted: 11/24/2020] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The classical homunculus of the human primary somatosensory cortex (S1) established by Penfield has mainly portrayed the functional organization of convexial cortex, namely Brodmann area (BA) 1. However, little is known about the functions in fissural cortex including BA2 and BA3. We aim at drawing a refined and detailed somatosensory homunculus of the entire S1. METHODS We recruited 20 patients with drug-resistant focal epilepsy who underwent stereo-electroencephalography for preoperative assessments. Direct electrical stimulation was performed for functional mapping. Montreal Neurological Institute coordinates of the stimulation sites lying in S1 were acquired. RESULTS Stimulation of 177 sites in S1 yielded 149 positive sites (84%), most of which were located in the sulcal cortex. The spatial distribution of different body-part representations across the S1 surface revealed that the gross medial-to-lateral sequence of body representations within the entire S1 was consistent with the classical "homunculus". And we identified several unreported body-part representations from the sulcal cortex, such as forehead, deep elbow and wrist joints, and some dorsal body regions. CONCLUSIONS Our results reveal general somatotopical characteristics of the entire S1 cortex and differences with the previous works of Penfield. SIGNIFICANCE The classical S1 homunculus was extended by providing further refinement and additional detail.
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Affiliation(s)
- Fengqiao Sun
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Guojun Zhang
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China.
| | - Liankun Ren
- Department of Neurology, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Tao Yu
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Zhiwei Ren
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Runshi Gao
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
| | - Xiaohua Zhang
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, No. 45, Changchun Street, Xicheng District, Beijing 100053, China
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Kilmarx J, Oblak E, Sulzer J, Lewis-Peacock J. Towards a common template for neural reinforcement of finger individuation. Sci Rep 2021; 11:1065. [PMID: 33441742 PMCID: PMC7806844 DOI: 10.1038/s41598-020-80166-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/14/2020] [Indexed: 12/04/2022] Open
Abstract
The inability to individuate finger movements is a common impairment following stroke. Conventional physical therapy ignores underlying neural changes with recovery, leaving it unclear why sensorimotor function often remains impaired. Functional MRI neurofeedback can monitor neural activity and reinforce it towards a healthy template to restore function. However, identifying an individualized training template may not be possible depending on the severity of impairment. In this study, we investigated the use of functional alignment of brain data across healthy participants to create an idealized neural template to be used as a training target for new participants. We employed multi-voxel pattern analyses to assess the prediction accuracy and robustness to missing data of pre-trained functional templates corresponding to individual finger presses. We found a significant improvement in classification accuracy (p < 0.001) of individual finger presses when group data was aligned based on function (88%) rather than anatomy (46%). Importantly, we found no significant drop in performance when aligning a new participant to a pre-established template as compared to including this new participant in the creation of a new template. These results indicate that functionally aligned templates could provide an effective surrogate training target for patients following neurological injury.
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Affiliation(s)
- Justin Kilmarx
- Department of Mechanical Engineering, The University of Texas at Austin, 2501 Wichita St, Austin, TX, 78712, USA.
| | - Ethan Oblak
- Department of Mechanical Engineering, The University of Texas at Austin, 2501 Wichita St, Austin, TX, 78712, USA
| | - James Sulzer
- Department of Mechanical Engineering, The University of Texas at Austin, 2501 Wichita St, Austin, TX, 78712, USA
| | - Jarrod Lewis-Peacock
- Department of Psychology, The University of Texas at Austin, 108 E Dean Keeton St, Austin, TX, 78712, USA
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Willoughby WR, Thoenes K, Bolding M. Somatotopic Arrangement of the Human Primary Somatosensory Cortex Derived From Functional Magnetic Resonance Imaging. Front Neurosci 2021; 14:598482. [PMID: 33488347 PMCID: PMC7817621 DOI: 10.3389/fnins.2020.598482] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 12/08/2020] [Indexed: 11/13/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) was used to estimate neuronal activity in the primary somatosensory cortex of six participants undergoing cutaneous tactile stimulation on skin areas spread across the entire body. Differences between the accepted somatotopic maps derived from Penfield's work and those generated by this fMRI study were sought, including representational transpositions or replications across the cortex. MR-safe pneumatic devices mimicking the action of a Wartenberg wheel supplied touch stimuli in eight areas. Seven were on the left side of the body: foot, lower, and upper leg, trunk beneath ribcage, anterior forearm, middle fingertip, and neck above the collarbone. The eighth area was the glabella. Activation magnitude was estimated as the maximum cross-correlation coefficient at a certain phase shift between ideal time series and measured blood oxygen level dependent (BOLD) time courses on the cortical surface. Maximally correlated clusters associated with each cutaneous area were calculated, and cortical magnification factors were estimated. Activity correlated to lower limb stimulation was observed in the paracentral lobule and superomedial postcentral region. Correlations to upper extremity stimulation were observed in the postcentral area adjacent to the motor hand knob. Activity correlated to trunk, face and neck stimulation was localized in the superomedial one-third of the postcentral region, which differed from Penfield's cortical homunculus.
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Affiliation(s)
- W. R. Willoughby
- Department of Radiology, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Kristina Thoenes
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Mark Bolding
- Department of Radiology, The University of Alabama at Birmingham, Birmingham, AL, United States
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Barron HC, Mars RB, Dupret D, Lerch JP, Sampaio-Baptista C. Cross-species neuroscience: closing the explanatory gap. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190633. [PMID: 33190601 PMCID: PMC7116399 DOI: 10.1098/rstb.2019.0633] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2020] [Indexed: 12/17/2022] Open
Abstract
Neuroscience has seen substantial development in non-invasive methods available for investigating the living human brain. However, these tools are limited to coarse macroscopic measures of neural activity that aggregate the diverse responses of thousands of cells. To access neural activity at the cellular and circuit level, researchers instead rely on invasive recordings in animals. Recent advances in invasive methods now permit large-scale recording and circuit-level manipulations with exquisite spatio-temporal precision. Yet, there has been limited progress in relating these microcircuit measures to complex cognition and behaviour observed in humans. Contemporary neuroscience thus faces an explanatory gap between macroscopic descriptions of the human brain and microscopic descriptions in animal models. To close the explanatory gap, we propose adopting a cross-species approach. Despite dramatic differences in the size of mammalian brains, this approach is broadly justified by preserved homology. Here, we outline a three-armed approach for effective cross-species investigation that highlights the need to translate different measures of neural activity into a common space. We discuss how a cross-species approach has the potential to transform basic neuroscience while also benefiting neuropsychiatric drug development where clinical translation has, to date, seen minimal success. This article is part of the theme issue 'Key relationships between non-invasive functional neuroimaging and the underlying neuronal activity'.
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Affiliation(s)
- Helen C. Barron
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Mansfield Road, Oxford OX1 3TH, UK
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, FMRIB, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Rogier B. Mars
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, FMRIB, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Donders Institute for Brain, Cognition and Behavior, Radboud University, 6525 AJ Nijmegen, The Netherlands
| | - David Dupret
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Mansfield Road, Oxford OX1 3TH, UK
| | - Jason P. Lerch
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, FMRIB, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, CanadaM5G 1L7
| | - Cassandra Sampaio-Baptista
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, FMRIB, John Radcliffe Hospital, Oxford OX3 9DU, UK
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QB, UK
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38
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Matuszewski J, Kossowski B, Bola Ł, Banaszkiewicz A, Paplińska M, Gyger L, Kherif F, Szwed M, Frackowiak RS, Jednoróg K, Draganski B, Marchewka A. Brain plasticity dynamics during tactile Braille learning in sighted subjects: Multi-contrast MRI approach. Neuroimage 2020; 227:117613. [PMID: 33307223 DOI: 10.1016/j.neuroimage.2020.117613] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 11/20/2020] [Accepted: 11/29/2020] [Indexed: 01/11/2023] Open
Abstract
A growing body of empirical evidence supports the notion of diverse neurobiological processes underlying learning-induced plasticity changes in the human brain. There are still open questions about how brain plasticity depends on cognitive task complexity, how it supports interactions between brain systems and with what temporal and spatial trajectory. We investigated brain and behavioural changes in sighted adults during 8-months training of tactile Braille reading whilst monitoring brain structure and function at 5 different time points. We adopted a novel multivariate approach that includes behavioural data and specific MRI protocols sensitive to tissue properties to assess local functional and structural and myelin changes over time. Our results show that while the reading network, located in the ventral occipitotemporal cortex, rapidly adapts to tactile input, sensory areas show changes in grey matter volume and intra-cortical myelin at different times. This approach has allowed us to examine and describe neuroplastic mechanisms underlying complex cognitive systems and their (sensory) inputs and (motor) outputs differentially, at a mesoscopic level.
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Affiliation(s)
- Jacek Matuszewski
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
| | - Bartosz Kossowski
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Łukasz Bola
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland; Institute of Psychology, Jagiellonian University, Krakow, Poland
| | - Anna Banaszkiewicz
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | | | - Lucien Gyger
- LREN, Department for Clinical Neurosciences, CHUV, University of Lausanne, Lausanne, Switzerland
| | - Ferath Kherif
- LREN, Department for Clinical Neurosciences, CHUV, University of Lausanne, Lausanne, Switzerland
| | - Marcin Szwed
- Institute of Psychology, Jagiellonian University, Krakow, Poland
| | | | - Katarzyna Jednoróg
- Laboratory of Language Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Bogdan Draganski
- LREN, Department for Clinical Neurosciences, CHUV, University of Lausanne, Lausanne, Switzerland; Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Artur Marchewka
- Laboratory of Brain Imaging, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
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Dempsey-Jones H, Wesselink DB, Friedman J, Makin TR. Organized Toe Maps in Extreme Foot Users. Cell Rep 2020; 28:2748-2756.e4. [PMID: 31509738 PMCID: PMC6899508 DOI: 10.1016/j.celrep.2019.08.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 03/28/2019] [Accepted: 08/05/2019] [Indexed: 12/11/2022] Open
Abstract
Although the fine-grained features of topographic maps in the somatosensory cortex can be shaped by everyday experience, it is unknown whether behavior can support the expression of somatotopic maps where they do not typically occur. Unlike the fingers, represented in all primates, individuated toe maps have only been found in non-human primates. Using 1-mm resolution fMRI, we identify organized toe maps in two individuals born without either upper limb who use their feet to substitute missing hand function and even support their profession as foot artists. We demonstrate that the ordering and structure of the artists’ toe representation mimics typical hand representation. We further reveal “hand-like” features of activity patterns, not only in the foot area but also similarly in the missing hand area. We suggest humans may have an innate capacity for forming additional topographic maps that can be expressed with appropriate experience. We ask if extreme behavior can cause the (re)emergence of somatotopic maps We investigated two foot artists, born without arms 7T fMRI shows individuated maps of up to 5 toes in the artists but not controls Activity in artists’ foot and hand areas was more “hand-like” than in controls
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Affiliation(s)
| | - Daan B Wesselink
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK; Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford OX3 9DU, UK.
| | - Jason Friedman
- Physical Therapy Department, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 699 7801, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 699 7801, Israel
| | - Tamar R Makin
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK
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40
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Makin TR, Flor H. Brain (re)organisation following amputation: Implications for phantom limb pain. Neuroimage 2020; 218:116943. [PMID: 32428706 PMCID: PMC7422832 DOI: 10.1016/j.neuroimage.2020.116943] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 05/10/2020] [Accepted: 05/11/2020] [Indexed: 12/11/2022] Open
Abstract
Following arm amputation the region that represented the missing hand in primary somatosensory cortex (S1) becomes deprived of its primary input, resulting in changed boundaries of the S1 body map. This remapping process has been termed 'reorganisation' and has been attributed to multiple mechanisms, including increased expression of previously masked inputs. In a maladaptive plasticity model, such reorganisation has been associated with phantom limb pain (PLP). Brain activity associated with phantom hand movements is also correlated with PLP, suggesting that preserved limb functional representation may serve as a complementary process. Here we review some of the most recent evidence for the potential drivers and consequences of brain (re)organisation following amputation, based on human neuroimaging. We emphasise other perceptual and behavioural factors consequential to arm amputation, such as non-painful phantom sensations, perceived limb ownership, intact hand compensatory behaviour or prosthesis use, which have also been related to both cortical changes and PLP. We also discuss new findings based on interventions designed to alter the brain representation of the phantom limb, including augmented/virtual reality applications and brain computer interfaces. These studies point to a close interaction of sensory changes and alterations in brain regions involved in body representation, pain processing and motor control. Finally, we review recent evidence based on methodological advances such as high field neuroimaging and multivariate techniques that provide new opportunities to interrogate somatosensory representations in the missing hand cortical territory. Collectively, this research highlights the need to consider potential contributions of additional brain mechanisms, beyond S1 remapping, and the dynamic interplay of contextual factors with brain changes for understanding and alleviating PLP.
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Affiliation(s)
- Tamar R Makin
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom; Wellcome Centre for Human Neuroimaging, University College London, London, UK.
| | - Herta Flor
- Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; Department of Psychology, School of Social Sciences, University of Mannheim, Germany; Center for Neuroplasticity and Pain (CNAP), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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41
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Sigurdsson HP, Jackson SR, Kim S, Dyke K, Jackson GM. A feasibility study for somatomotor cortical mapping in Tourette syndrome using neuronavigated transcranial magnetic stimulation. Cortex 2020; 129:175-187. [DOI: 10.1016/j.cortex.2020.04.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 01/06/2020] [Accepted: 04/21/2020] [Indexed: 01/20/2023]
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Panchuelo RMS, Eldeghaidy S, Marshall A, McGlone F, Francis ST, Favorov O. A nociresponsive specific area of human somatosensory cortex within BA3a: BA3c? Neuroimage 2020; 221:117187. [PMID: 32711068 PMCID: PMC7762820 DOI: 10.1016/j.neuroimage.2020.117187] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/14/2020] [Accepted: 07/19/2020] [Indexed: 01/03/2023] Open
Abstract
It is well recognized that in primates, including humans, noxious body stimulation evokes a neural response in the posterior bank of the central sulcus, in Brodmann cytoarchitectonic subdivisions 3b and 1 of the primary somatosensory cortex. This response is associated with the 1st/sharp pain and contributes to sensory discriminative aspects of pain perception and spatial localization of the noxious stimulus. However, neurophysiological studies in New World monkeys predict that in humans noxious stimulation also evokes a separate neural response-mediated by C-afferent drive and associated with the 2nd/burning pain-in the depth of the central sulcus in Brodmann area 3a (BA3a) at the transition between the somatosensory and motor cortices. To evoke such a response, it is necessary to use multi-second duration noxious stimulation, rather than brief laser pulses. Given the limited human pain-imaging literature on cortical responses induced by C-nociceptive input specifically within BA3a, here we used high spatial resolution 7T fMRI to study the response to thermonoxious skin stimulation. We observed the predicted response of BA3a in the depth of the central sulcus in five human volunteers. Review of the available evidence suggests that the nociresponsive region in the depth of the central sulcus is a structurally and functionally distinct cortical area that should not be confused with proprioceptive BA3a. It is most likely engaged in interoception and control of the autonomic nervous system, and contributes to the sympathetic response to noxious stimulation, arguably the most intolerable aspect of pain experience. Ablation of this region has been shown to reduce pain sensibility and might offer an effective means of ameliorating some pathological pain conditions.
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Affiliation(s)
- Rosa M Sanchez Panchuelo
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Sally Eldeghaidy
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK; Future Food Beacon, School of Biosciences, University of Nottingham, Nottingham, UK
| | - Andrew Marshall
- Institute of Aging and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Francis McGlone
- School of natural Science and Psychology, Liverpool John Moores University, Liverpool, UK
| | - Susan T Francis
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK; NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
| | - Oleg Favorov
- Department of Biomedical Engineering, University of North Carolina, CB #7575, Chapel Hill, NC 27599, USA.
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Assessment of cortical reorganization and preserved function in phantom limb pain: a methodological perspective. Sci Rep 2020; 10:11504. [PMID: 32661345 PMCID: PMC7359300 DOI: 10.1038/s41598-020-68206-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/19/2020] [Indexed: 02/07/2023] Open
Abstract
Phantom limb pain (PLP) has been associated with reorganization in primary somatosensory cortex (S1) and preserved S1 function. Here we examined if methodological differences in the assessment of cortical representations might explain these findings. We used functional magnetic resonance imaging during a virtual reality movement task, analogous to the classical mirror box task, in twenty amputees with and without PLP and twenty matched healthy controls. We assessed the relationship between task-related activation maxima and PLP intensity in S1 and motor cortex (M1) in individually-defined or group-conjoint regions of interest (ROI) (overlap of task-related activation between the groups). We also measured cortical distances between both locations and correlated them with PLP intensity. Amputees compared to controls showed significantly increased activation in M1, S1 and S1M1 unrelated to PLP. Neural activity in M1 was positively related to PLP intensity in amputees with PLP when a group-conjoint ROI was chosen. The location of activation maxima differed between groups in S1 and M1. Cortical distance measures were unrelated to PLP. These findings suggest that sensory and motor maps differentially relate to PLP and that methodological differences might explain discrepant findings in the literature.
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Germann J, Chakravarty MM, Collins DL, Petrides M. Tight Coupling between Morphological Features of the Central Sulcus and Somatomotor Body Representations: A Combined Anatomical and Functional MRI Study. Cereb Cortex 2020; 30:1843-1854. [PMID: 31711125 PMCID: PMC7132904 DOI: 10.1093/cercor/bhz208] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/15/2019] [Accepted: 08/15/2019] [Indexed: 01/18/2023] Open
Abstract
Pioneering research established the concept of somatotopic organization of the primary motor and somatosensory cortex along the central sulcus as depicted in the widely known schematic illustration (the "homunculus") by Penfield and colleagues. With the exception of the hand, however, a precise relationship between morphological features of the central sulcus and the representation of various parts of the body has not been addressed. To investigate whether such relations between anatomical features and functional body representations exist, we first examined central sulcus morphology in detail and then conducted a functional magnetic resonance imaging experiment to establish somatomotor representations. This study established that the central sulcus is composed of five distinct sulcal segments and demonstrated that each segment relates systematically to the sensorimotor representation of distinct parts of the body. Thus, local morphology predicts the localization of body representations with precision, raising fundamental questions regarding functional and morphological differentiation.
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Affiliation(s)
- Jürgen Germann
- Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, Montreal H3A 2B4, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal H3A 2B4, Canada
| | - M Mallar Chakravarty
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal H3A 2B4, Canada
- CIC, Douglas Mental Health Institute, McGill University, Montreal, H4H 1R3, Canada
| | - D Louis Collins
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal H3A 2B4, Canada
| | - Michael Petrides
- Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, Montreal H3A 2B4, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal H3A 2B4, Canada
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Huber L, Finn ES, Handwerker DA, Bönstrup M, Glen DR, Kashyap S, Ivanov D, Petridou N, Marrett S, Goense J, Poser BA, Bandettini PA. Sub-millimeter fMRI reveals multiple topographical digit representations that form action maps in human motor cortex. Neuroimage 2020; 208:116463. [DOI: 10.1016/j.neuroimage.2019.116463] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 11/10/2019] [Accepted: 12/11/2019] [Indexed: 12/31/2022] Open
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Lee CR, Najafizadeh L, Margolis DJ. Investigating learning-related neural circuitry with chronic in vivo optical imaging. Brain Struct Funct 2020; 225:467-480. [PMID: 32006147 DOI: 10.1007/s00429-019-02001-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 12/05/2019] [Indexed: 10/25/2022]
Abstract
Fundamental aspects of brain function, including development, plasticity, learning, and memory, can take place over time scales of days to years. Chronic in vivo imaging of neural activity with cellular resolution is a powerful method for tracking the long-term activity of neural circuits. We review recent advances in our understanding of neural circuit function from diverse brain regions that have been enabled by chronic in vivo cellular imaging. Insight into the neural basis of learning and decision-making, in particular, benefit from the ability to acquire longitudinal data from genetically identified neuronal populations, deep brain areas, and subcellular structures. We propose that combining chronic imaging with further experimental and computational innovations will advance our understanding of the neural circuit mechanisms of brain function.
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Affiliation(s)
- Christian R Lee
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Laleh Najafizadeh
- Department of Electrical and Computer Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - David J Margolis
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, 08854, USA.
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Abstract
Human brain function research has evolved dramatically in the last decades. In this chapter the role of modern methods of recording brain activity in understanding human brain function is explained. Current knowledge of brain function relevant to brain-computer interface (BCI) research is detailed, with an emphasis on the motor system which provides an exceptional level of detail to decoding of intended or attempted movements in paralyzed beneficiaries of BCI technology and translation to computer-mediated actions. BCI technologies that stand to benefit the most of the detailed organization of the human cortex are, and for the foreseeable future are likely to be, reliant on intracranial electrodes. These evolving technologies are expected to enable severely paralyzed people to regain the faculty of movement and speech in the coming decades.
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Affiliation(s)
- Nick F Ramsey
- Brain Center, University Medical Center Utrecht, Utrecht, The Netherlands.
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48
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Kaas A, Goebel R, Valente G, Sorger B. Topographic Somatosensory Imagery for Real-Time fMRI Brain-Computer Interfacing. Front Hum Neurosci 2019; 13:427. [PMID: 31920588 PMCID: PMC6915074 DOI: 10.3389/fnhum.2019.00427] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 11/18/2019] [Indexed: 11/23/2022] Open
Abstract
Real-time functional magnetic resonance imaging (fMRI) is a promising non-invasive method for brain-computer interfaces (BCIs). BCIs translate brain activity into signals that allow communication with the outside world. Visual and motor imagery are often used as information-encoding strategies, but can be challenging if not grounded in recent experience in these modalities, e.g., in patients with locked-in-syndrome (LIS). In contrast, somatosensory imagery might constitute a more suitable information-encoding strategy as the somatosensory function is often very robust. Somatosensory imagery has been shown to activate the somatotopic cortex, but it has been unclear so far whether it can be reliably detected on a single-trial level and successfully classified according to specific somatosensory imagery content. Using ultra-high field 7-T fMRI, we show reliable and high-accuracy single-trial decoding of left-foot (LF) vs. right-hand (RH) somatosensory imagery. Correspondingly, higher decoding accuracies were associated with greater spatial separation of hand and foot decoding-weight patterns in the primary somatosensory cortex (S1). Exploiting these novel neuroscientific insights, we developed-and provide a proof of concept for-basic BCI communication by showing that binary (yes/no) answers encoded by somatosensory imagery can be decoded with high accuracy in simulated real-time (in 7 subjects) as well as in real-time (1 subject). This study demonstrates that body part-specific somatosensory imagery differentially activates somatosensory cortex in a topographically specific manner; evidence which was surprisingly still lacking in the literature. It also offers proof of concept for a novel somatosensory imagery-based fMRI-BCI control strategy, with particularly high potential for visually and motor-impaired patients. The strategy could also be transferred to lower MRI field strengths and to mobile functional near-infrared spectroscopy. Finally, given that communication BCIs provide the BCI user with a form of feedback based on their brain signals and can thus be considered as a specific form of neurofeedback, and that repeated use of a BCI has been shown to enhance underlying representations, we expect that the current BCI could also offer an interesting new approach for somatosensory rehabilitation training in the context of stroke and phantom limb pain.
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Affiliation(s)
- Amanda Kaas
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
- Maastricht Brain Imaging Center, Maastricht University, Maastricht, Netherlands
| | - Rainer Goebel
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
- Maastricht Brain Imaging Center, Maastricht University, Maastricht, Netherlands
| | - Giancarlo Valente
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
- Maastricht Brain Imaging Center, Maastricht University, Maastricht, Netherlands
| | - Bettina Sorger
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
- Maastricht Brain Imaging Center, Maastricht University, Maastricht, Netherlands
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49
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Mancini F, Wang AP, Schira MM, Isherwood ZJ, McAuley JH, Iannetti GD, Sereno MI, Moseley GL, Rae CD. Fine-Grained Mapping of Cortical Somatotopies in Chronic Complex Regional Pain Syndrome. J Neurosci 2019; 39:9185-9196. [PMID: 31570533 PMCID: PMC6855684 DOI: 10.1523/jneurosci.2005-18.2019] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 08/13/2019] [Accepted: 08/19/2019] [Indexed: 01/21/2023] Open
Abstract
It has long been thought that severe chronic pain conditions, such as complex regional pain syndrome (CRPS), are not only associated with, but even maintained by a reorganization of the somatotopic representation of the affected limb in primary somatosensory cortex (S1). This notion has driven treatments that aim to restore S1 representations in CRPS patients, such as sensory discrimination training and mirror therapy. However, this notion is based on both indirect and incomplete evidence obtained with imaging methods with low spatial resolution. Here, we used fMRI to characterize the S1 representation of the affected and unaffected hand in humans (of either sex) with unilateral CRPS. The cortical area, location, and geometry of the S1 representation of the CRPS hand were largely comparable with those of both the unaffected hand and healthy controls. We found no differential relation between affected versus unaffected hand map measures and clinical measures (pain severity, upper limb disability, disease duration). Thus, if any map reorganization occurs, it does not appear to be directly related to pain and disease severity. These findings compel us to reconsider the cortical mechanisms underlying CRPS and the rationale for interventions that aim to "restore" somatotopic representations to treat pain.SIGNIFICANCE STATEMENT This study shows that the spatial map of the fingers in somatosensory cortex is largely preserved in chronic complex regional pain syndrome (CRPS). These findings challenge the treatment rationale for restoring somatotopic representations in complex regional pain syndrome patients.
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Affiliation(s)
- Flavia Mancini
- Computational and Biological Learning, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom,
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Audrey P Wang
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- Faculty of Medicine and Health and Faculty of Health Sciences, University of Sydney, Sydney, New South Wales 2145, Australia
| | - Mark M Schira
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Psychology, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Zoey J Isherwood
- School of Psychology, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - James H McAuley
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Giandomenico D Iannetti
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
- Neuroscience and Behaviour Laboratory, Istituto Italiano di Tecnologia, Rome 00161, Italy
| | - Martin I Sereno
- Department of Psychology, University College London, London WC1E 6BT, United Kingdom
- Department of Psychology, San Diego State University, San Diego, California 92182, and
| | - G Lorimer Moseley
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- IMPACT in Health, University of South Australia, Adelaide, South Australia, Australia
| | - Caroline D Rae
- Neuroscience Research Australia, Sydney, New South Wales 2031, Australia
- School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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50
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Multi-site harmonization of 7 tesla MRI neuroimaging protocols. Neuroimage 2019; 206:116335. [PMID: 31712167 PMCID: PMC7212005 DOI: 10.1016/j.neuroimage.2019.116335] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 10/25/2019] [Accepted: 11/04/2019] [Indexed: 12/11/2022] Open
Abstract
Increasing numbers of 7 T (7 T) magnetic resonance imaging (MRI) scanners are in research and clinical use. 7 T MRI can increase the scanning speed, spatial resolution and contrast-to-noise-ratio of many neuroimaging protocols, but technical challenges in implementation have been addressed in a variety of ways across sites. In order to facilitate multi-centre studies and ensure consistency of findings across sites, it is desirable that 7 T MRI sites implement common high-quality neuroimaging protocols that can accommodate different scanner models and software versions. With the installation of several new 7 T MRI scanners in the United Kingdom, the UK7T Network was established with an aim to create a set of harmonized structural and functional neuroimaging sequences and protocols. The Network currently includes five sites, which use three different scanner platforms, provided by two different vendors. Here we describe the harmonization of functional and anatomical imaging protocols across the three different scanner models, detailing the necessary changes to pulse sequences and reconstruction methods. The harmonized sequences are fully described, along with implementation details. Example datasets acquired from the same subject on all Network scanners are made available. Based on these data, an evaluation of the harmonization is provided. In addition, the implementation and validation of a common system calibration process is described.
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