51
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Little S, Bonaiuto J, Barnes G, Bestmann S. Human motor cortical beta bursts relate to movement planning and response errors. PLoS Biol 2019; 17:e3000479. [PMID: 31584933 PMCID: PMC6795457 DOI: 10.1371/journal.pbio.3000479] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 10/16/2019] [Accepted: 09/10/2019] [Indexed: 11/30/2022] Open
Abstract
Motor cortical beta activity (13-30 Hz) is a hallmark signature of healthy and pathological movement, but its behavioural relevance remains unclear. Using high-precision magnetoencephalography (MEG), we show that during the classical event-related desynchronisation (ERD) and event-related synchronisation (ERS) periods, motor cortical beta activity in individual trials (n > 12,000) is dominated by high amplitude, transient, and infrequent bursts. Beta burst probability closely matched the trial-averaged beta amplitude in both the pre- and post-movement periods, but individual bursts were spatially more focal than the classical ERS peak. Furthermore, prior to movement (ERD period), beta burst timing was related to the degree of motor preparation, with later bursts resulting in delayed response times. Following movement (ERS period), the first beta burst was delayed by approximately 100 milliseconds when an incorrect response was made. Overall, beta burst timing was a stronger predictor of single trial behaviour than beta burst rate or single trial beta amplitude. This transient nature of motor cortical beta provides new constraints for theories of its role in information processing within and across cortical circuits, and its functional relevance for behaviour in both healthy and pathological movement.
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Affiliation(s)
- Simon Little
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, United Kingdom
- Department of Neurology, University of San Francisco, California, United States of America
| | - James Bonaiuto
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, United Kingdom
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, London, United Kingdom
- Institut des Sciences Cognitives Marc Jeannerod, CNRS UMR 5229, Bron, France
- Université Claude Bernard Lyon I, Lyon, France
| | - Gareth Barnes
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Sven Bestmann
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, United Kingdom
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, London, United Kingdom
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State-Dependent Effects of Transcranial Oscillatory Currents on the Motor System during Action Observation. Sci Rep 2019; 9:12858. [PMID: 31492895 PMCID: PMC6731229 DOI: 10.1038/s41598-019-49166-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 08/16/2019] [Indexed: 12/24/2022] Open
Abstract
We applied transcranial alternating current stimulation (tACS) to the primary motor cortex (M1) at different frequencies during an index–thumb pinch-grip observation task. To estimate changes in the corticospinal output, we used the size of motor evoked potentials (MEPs) obtained by transcranial magnetic stimulation (TMS) of M1 using an online MRI-guided simultaneous TMS-tACS approach. The results of the beta-tACS confirm a non-selective increase in corticospinal excitability in subjects at rest; an increase was observed for both of the tested hand muscles, the first dorsal interosseous (FDI) and the abductor digiti minimi (ADM). However, during action observation of the pinch-grip movement, the increase of corticospinal excitability was only observed for the prime mover FDI muscle and took place during alpha-tACS, while gamma-tACS affected both the FDI and control muscle (ADM) responses. These phenomena likely reflect the hypothesis that the mu and gamma rhythms specifically index the downstream modulation of primary sensorimotor areas by engaging mirror neuron activity. The current neuromodulation approach confirms that tACS can be used to induce neurophysiologically detectable state-dependent enhancement effects, even in complex motor-cognitive tasks.
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53
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Khademi F, Royter V, Gharabaghi A. Distinct Beta-band Oscillatory Circuits Underlie Corticospinal Gain Modulation. Cereb Cortex 2019; 28:1502-1515. [PMID: 29415124 PMCID: PMC6093341 DOI: 10.1093/cercor/bhy016] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 01/09/2018] [Indexed: 01/13/2023] Open
Abstract
Rhythmic synchronization of neurons is known to affect neuronal interactions. In the motor system, oscillatory power fluctuations modulate corticospinal excitability. However, previous research addressing phase-specific gain modulation in the motor system has resulted in contradictory findings. It remains unclear how many time windows of increased responsiveness each oscillatory cycle provides. Moreover, we still lack conclusive evidence as to whether the motor cortex entails an intrinsic response modulation along the rhythm cycle, as shown for spinal neurons. We investigated this question with single-pulse transcranial magnetic stimulation over the primary motor cortex at rest. Application of near-motor threshold stimuli revealed a frequency- and phase-specific gain modulation at both cortical and spinal level, independent of the spontaneous oscillatory power fluctuations at each level. We detected bilateral sensorimotor circuits in the lower beta-band (14–17 Hz) and unilateral corticospinal circuits in the upper beta-band (20–24 Hz). These findings provide novel evidence that intrinsic activity in the human motor cortex modulates input gain along the beta oscillatory cycle within distinct circuits. In accordance with periodic alternations of synchronous hyper- and depolarization, increased neuronal responsiveness occurred once per oscillatory beta cycle. This information may lead to new brain state-dependent and circuit-specific interventions for targeted neuromodulation.
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Affiliation(s)
- Fatemeh Khademi
- Division of Functional and Restorative Neurosurgery, and Centre for Integrative Neuroscience, Eberhard Karls University Tuebingen, 72076 Tuebingen, Germany
| | - Vladimir Royter
- Division of Functional and Restorative Neurosurgery, and Centre for Integrative Neuroscience, Eberhard Karls University Tuebingen, 72076 Tuebingen, Germany
| | - Alireza Gharabaghi
- Division of Functional and Restorative Neurosurgery, and Centre for Integrative Neuroscience, Eberhard Karls University Tuebingen, 72076 Tuebingen, Germany
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54
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Benedetto A, Morrone MC, Tomassini A. The Common Rhythm of Action and Perception. J Cogn Neurosci 2019; 32:187-200. [PMID: 31210564 DOI: 10.1162/jocn_a_01436] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Research in the last decade has undermined the idea of perception as a continuous process, providing strong empirical support for its rhythmic modulation. More recently, it has been revealed that the ongoing motor processes influence the rhythmic sampling of sensory information. In this review, we will focus on a growing body of evidence suggesting that oscillation-based mechanisms may structure the dynamic interplay between the motor and sensory system and provide a unified temporal frame for their effective coordination. We will describe neurophysiological data, primarily collected in animals, showing phase-locking of neuronal oscillations to the onset of (eye) movements. These data are complemented by novel evidence in humans, which demonstrate the behavioral relevance of these oscillatory modulations and their domain-general nature. Finally, we will discuss the possible implications of these modulations for action-perception coupling mechanisms.
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55
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Sabel BA, Hamid AIA, Borrmann C, Speck O, Antal A. Transorbital alternating current stimulation modifies BOLD activity in healthy subjects and in a stroke patient with hemianopia: A 7 Tesla fMRI feasibility study. Int J Psychophysiol 2019; 154:80-92. [PMID: 30978369 DOI: 10.1016/j.ijpsycho.2019.04.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 03/28/2019] [Accepted: 04/04/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND Modifying brain activity using non-invasive, low intensity transcranial electrical brain stimulation (TES) has rapidly increased during the past 20 years. Alternating current stimulation (ACS), for example, has been shown to alter brain rhythm activities and modify neuronal functioning in the visual system. Daily application of transorbital ACS to patients with optic nerve damage induces functional connectivity reorganization, and partially restores vision. While ACS is thought to mainly modify neuronal mechanisms, e.g. changes in brain oscillations that can be detected by EEG, it is still an open question, whether and how it may alter BOLD activity. OBJECTIVE We evaluated whether transorbital ACS modulates BOLD activity in early visual cortex using high-resolution 7 Tesla functional magnetic resonance imaging (fMRI). METHODS In this feasibility study transorbital ACS in the alpha range and sham ACS was applied in a random block design in five healthy subjects for 20 min at 1 mA. Brain activation in the visual areas V1, V2 and V3 were measured using 7 Tesla fMRI-based retinotopic mapping at the time points before (baseline) and after stimulation. In addition, we collected data from one hemianopic stroke patient with visual cortex damage after ten daily sessions with 25-50 min stimulation duration. RESULTS In healthy subjects transorbital ACS increased the activated cortical surface area, decreased the fMRI response amplitude and increased coherence in the visual cortex, which was most prominent in the full field task. In the patient, stimulation improved contrast sensitivity in the central visual field. BOLD amplitudes and coherence values were increased in most early visual areas in both hemispheres, with the most pronounced activation detected during eccentricity testing in retinotopic mapping. CONCLUSIONS This feasibility study showed that transorbital ACS modifies BOLD activity to visual stimulation, which outlasts the duration of the AC stimulation. This is in line with earlier neurophysiological findings of increased power in EEG recordings and functional connectivity reorganization in patients with impaired vision. Accordingly, the larger BOLD response area after stimulation can be explained by more coherent activation and lower variability in the activation. Alternatively, increased neuronal activity can also be taken into account. Controlled trials are needed to systematically evaluate the potential of repetitive transorbital ACS to improve visual function after visual pathway stroke and to determine the cause-effect relationship between neural and BOLD activity changes.
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Affiliation(s)
- Bernhard A Sabel
- Institute of Medical Psychology, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany.
| | - Aini Ismafairus Abd Hamid
- Department of Biomedical Magnetic Resonance, Institute for Experimental Physics, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany; Department of Neurosciences, School of Medical Sciences Health Campus, Jalan Hospital USM, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Carolin Borrmann
- Institute of Medical Psychology, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany
| | - Oliver Speck
- Center for Behavioral Brain Sciences, Magdeburg, Germany; Department of Biomedical Magnetic Resonance, Institute for Experimental Physics, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany; Department of Neurosciences, School of Medical Sciences Health Campus, Jalan Hospital USM, 16150 Kubang Kerian, Kelantan, Malaysia; Leibniz Institute for Neurobiology, Magdeburg, Germany; German Center for Neurodegenerative Disease (DZNE), Germany
| | - Andrea Antal
- Institute of Medical Psychology, Otto-von-Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany; Department of Clinical Neurophysiology, University Medical Center Göttingen, Göttingen, Germany
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Dubbioso R, Manganelli F, Siebner HR, Di Lazzaro V. Fast Intracortical Sensory-Motor Integration: A Window Into the Pathophysiology of Parkinson's Disease. Front Hum Neurosci 2019; 13:111. [PMID: 31024277 PMCID: PMC6463734 DOI: 10.3389/fnhum.2019.00111] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 03/13/2019] [Indexed: 01/09/2023] Open
Abstract
Parkinson's Disease (PD) is a prototypical basal ganglia disorder. Nigrostriatal dopaminergic denervation leads to progressive dysfunction of the cortico-basal ganglia-thalamo-cortical sensorimotor loops, causing the classical motor symptoms. Although the basal ganglia do not receive direct sensory input, they are important for sensorimotor integration. Therefore, the basal ganglia dysfunction in PD may profoundly affect sensory-motor interaction in the cortex. Cortical sensorimotor integration can be probed with transcranial magnetic stimulation (TMS) using a well-established conditioning-test paradigm, called short-latency afferent inhibition (SAI). SAI probes the fast-inhibitory effect of a conditioning peripheral electrical stimulus on the motor response evoked by a TMS test pulse given to the contralateral primary motor cortex (M1). Since SAI occurs at latencies that match the peaks of early cortical somatosensory potentials, the cortical circuitry generating SAI may play an important role in rapid online adjustments of cortical motor output to changes in somatosensory inputs. Here we review the existing studies that have used SAI to examine how PD affects fast cortical sensory-motor integration. Studies of SAI in PD have yielded variable results, showing reduced, normal or even enhanced levels of SAI. This variability may be attributed to the fact that the strength of SAI is influenced by several factors, such as differences in dopaminergic treatment or the clinical phenotype of PD. Inter-individual differences in the expression of SAI has been shown to scale with individual motor impairment as revealed by UPDRS motor score and thus, may reflect the magnitude of dopaminergic neurodegeneration. The magnitude of SAI has also been linked to cognitive dysfunction, and it has been suggested that SAI also reflects cholinergic denervation at the cortical level. Together, the results indicate that SAI is a useful marker of disease-related alterations in fast cortical sensory-motor integration driven by subcortical changes in the dopaminergic and cholinergic system. Since a multitude of neurobiological factors contribute to the magnitude of inhibition, any mechanistic interpretation of SAI changes in PD needs to consider the group characteristics in terms of phenotypical spectrum, disease stage, and medication.
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Affiliation(s)
- Raffaele Dubbioso
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University Federico II of Naples, Napoli, Italy
| | - Fiore Manganelli
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University Federico II of Naples, Napoli, Italy
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark.,Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark.,Institute for Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, University Campus Bio-Medico, Rome, Italy
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57
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Khademi F, Royter V, Gharabaghi A. State-dependent brain stimulation: Power or phase? Brain Stimul 2019; 12:296-299. [DOI: 10.1016/j.brs.2018.10.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 10/19/2018] [Accepted: 10/22/2018] [Indexed: 12/20/2022] Open
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58
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Brighina F, Curatolo M, Cosentino G, De Tommaso M, Battaglia G, Sarzi-Puttini PC, Guggino G, Fierro B. Brain Modulation by Electric Currents in Fibromyalgia: A Structured Review on Non-invasive Approach With Transcranial Electrical Stimulation. Front Hum Neurosci 2019; 13:40. [PMID: 30804771 PMCID: PMC6378756 DOI: 10.3389/fnhum.2019.00040] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 01/24/2019] [Indexed: 01/13/2023] Open
Abstract
Fibromyalgia syndrome (FMS) is a complex disorder where widespread musculoskeletal pain is associated with many heterogenous symptoms ranging from affective disturbances to cognitive dysfunction and central fatigue. FMS is currently underdiagnosed and often very poorly responsive to pharmacological treatment. Pathophysiology of the disease remains still obscure even if in the last years fine structural and functional cerebral abnormalities have been identified, principally by neurophysiological and imaging studies delineating disfunctions in pain perception, processing and control systems. On such basis, recently, neurostimulation of brain areas involved in mechanism of pain processing and control (primary motor cortex: M1 and dorsolateral prefrontal cortex: DLPFC) has been explored by means of different approaches and particularly through non-invasive brain stimulation techniques (transcranial magnetic and electric stimulation: TMS and tES). Here we summarize studies on tES application in FMS. The great majority of reports, based on direct currents (transcranial direct currents stimulation: tDCS) and targeting M1, showed efficacy on pain measures and less on cognitive and affective symptoms, even if several aspects as maintenance of therapeutical effects and optimal stimulation parameters remain to be established. Differently, stimulation of DLPFC, explored in a few studies, was ineffective on pain and showed limited effects on cognitive and affective symptoms. Very recently new tES techniques as high-density tDCS (HD-tDCS), transcranial random noise stimulation (tRNS) and tDCS devices for home-based treatment have been explored in FMS with interesting even if very preliminary results opening interesting perspectives for more effective, well tolerated, cheap and easy therapeutic approaches.
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Affiliation(s)
- Filippo Brighina
- Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata (BIND), Università degli Studi di Palermo, Palermo, Italy
| | - Massimiliano Curatolo
- Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata (BIND), Università degli Studi di Palermo, Palermo, Italy
| | - Giuseppe Cosentino
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.,IRCCS Mondino Foundation, Pavia, Italy
| | - Marina De Tommaso
- Unità di Neurofisiopatologia del Dolore, Dipartimento di Scienze Mediche di Base, Neuroscienze e Organi di Senso (SMBNOS), Università degli Studi di Bari Aldo Moro, Bari, Italy
| | - Giuseppe Battaglia
- Dipartimento di Scienze Psicologiche, Pedagogiche, dell'Esercizio Fisico e della Formazione, Università degli Studi di Palermo, Palermo, Italy
| | | | - Giuliana Guggino
- Dipartimento Biomedico di Medicina Interna e Specialistica (DIBIMIS), Università degli Studi di Palermo, Palermo, Italy
| | - Brigida Fierro
- Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata (BIND), Università degli Studi di Palermo, Palermo, Italy
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Cabral-Calderin Y, Wilke M. Probing the Link Between Perception and Oscillations: Lessons from Transcranial Alternating Current Stimulation. Neuroscientist 2019; 26:57-73. [PMID: 30730265 PMCID: PMC7003153 DOI: 10.1177/1073858419828646] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Brain oscillations are regarded as important for perception as they open and close time windows for neural spiking to enable the effective communication within and across brain regions. In the past, studies on perception primarily relied on the use of electrophysiological techniques for probing a correlative link between brain oscillations and perception. The emergence of noninvasive brain stimulation techniques such as transcranial alternating current stimulation (tACS) provides the possibility to study the causal contribution of specific oscillatory frequencies to perception. Here, we review the studies on visual, auditory, and somatosensory perception that employed tACS to probe the causality of brain oscillations for perception. The current literature is consistent with a causal role of alpha and gamma oscillations in parieto-occipital regions for visual perception and theta and gamma oscillations in auditory cortices for auditory perception. In addition, the sensory gating by alpha oscillations applies not only to the visual but also to the somatosensory domain. We conclude that albeit more refined perceptual paradigms and individualized stimulation practices remain to be systematically adopted, tACS is a promising tool for establishing a causal link between neural oscillations and perception.
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Affiliation(s)
- Yuranny Cabral-Calderin
- MEG Unit, Brain Imaging Center, Goethe University Frankfurt, Frankfurt am Main, Germany.,German Resilience Center, University Medical Center Mainz, Mainz, Germany
| | - Melanie Wilke
- Department of Cognitive Neurology, University Medicine Göttingen, Göttingen, Germany.,German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany.,DFG Center for Nanoscale Microscopy & Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
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60
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Mansouri F, Fettes P, Schulze L, Giacobbe P, Zariffa J, Downar J. A Real-Time Phase-Locking System for Non-invasive Brain Stimulation. Front Neurosci 2018; 12:877. [PMID: 30559641 PMCID: PMC6287008 DOI: 10.3389/fnins.2018.00877] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/12/2018] [Indexed: 12/16/2022] Open
Abstract
Non-invasive brain stimulation techniques are entering widespread use for the investigation and treatment of a range of neurological and neuropsychiatric disorders. However, most current techniques are ‘open-loop’, without feedback from target brain region activity; this limitation could contribute to heterogeneous effects seen for nominally ‘inhibitory’ and ‘excitatory’ protocols across individuals. More potent and consistent effects may ensue from closed-loop and, in particular, phase-locked brain stimulation. In this work, a closed-loop brain stimulation system is introduced that can analyze EEG data in real-time, provide a forecast of the phase of an underlying brain rhythm of interest, and control pulsed transcranial electromagnetic stimulation to deliver pulses at a specific phase of the target frequency band. The technique was implemented using readily available equipment such as a basic EEG system, a low-cost Arduino board and MATLAB scripts. The phase-locked brain stimulation method was tested in 5 healthy volunteers and its phase-locking performance evaluated at 0, 90, 180, and 270 degree phases in theta and alpha frequency bands. On average phase locking values of 0.55° ± 0.11° and 0.52° ± 0.14° and error angles of 11° ± 11° and 3.3° ± 18° were achieved for theta and alpha stimulation, respectively. Despite the low-cost hardware implementation, signal processing time generated a phase delay of only 3.8° for theta and 57° for alpha stimulation, both readily accommodated in the pulse trigger algorithm. This work lays the methodological steps for achieving phase-locked brain stimulation for brief-pulse transcranial electrical stimulation (tES) and repetitive transcranial magnetic stimulation (rTMS), facilitating further research on the effect of stimulation phase for these techniques.
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Affiliation(s)
- Farrokh Mansouri
- Institute of Biomaterial and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Peter Fettes
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Laura Schulze
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - Peter Giacobbe
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Centre for Mental Health, University Health Network, Toronto, ON, Canada.,Harquail Centre for Neuromodulation, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Jose Zariffa
- Institute of Biomaterial and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.,Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada
| | - Jonathan Downar
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Centre for Mental Health, University Health Network, Toronto, ON, Canada.,Krembil Research Institute, University Health Network, Toronto, ON, Canada
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61
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Liu A, Vöröslakos M, Kronberg G, Henin S, Krause MR, Huang Y, Opitz A, Mehta A, Pack CC, Krekelberg B, Berényi A, Parra LC, Melloni L, Devinsky O, Buzsáki G. Immediate neurophysiological effects of transcranial electrical stimulation. Nat Commun 2018; 9:5092. [PMID: 30504921 PMCID: PMC6269428 DOI: 10.1038/s41467-018-07233-7] [Citation(s) in RCA: 252] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 10/18/2018] [Indexed: 12/19/2022] Open
Abstract
Noninvasive brain stimulation techniques are used in experimental and clinical fields for their potential effects on brain network dynamics and behavior. Transcranial electrical stimulation (TES), including transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), has gained popularity because of its convenience and potential as a chronic therapy. However, a mechanistic understanding of TES has lagged behind its widespread adoption. Here, we review data and modelling on the immediate neurophysiological effects of TES in vitro as well as in vivo in both humans and other animals. While it remains unclear how typical TES protocols affect neural activity, we propose that validated models of current flow should inform study design and artifacts should be carefully excluded during signal recording and analysis. Potential indirect effects of TES (e.g., peripheral stimulation) should be investigated in more detail and further explored in experimental designs. We also consider how novel technologies may stimulate the next generation of TES experiments and devices, thus enhancing validity, specificity, and reproducibility.
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Affiliation(s)
- Anli Liu
- New York University Comprehensive Epilepsy Center, 223 34th Street, New York, NY, 10016, USA.
- Department of Neurology, NYU Langone Health, 222 East 41st Street, 14th Floor, New York, NY, 10016, USA.
| | - Mihály Vöröslakos
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, Faculty of Medicine, University of Szeged, 10 Dom sq., Szeged, H-6720, Hungary
- New York University Neuroscience Institute, 435 East 30th Street, New York, NY, 10016, USA
| | - Greg Kronberg
- Department of Biomedical Engineering, City College of New York, 160 Convent Ave, New York, NY, 10031, USA
| | - Simon Henin
- New York University Comprehensive Epilepsy Center, 223 34th Street, New York, NY, 10016, USA
- Department of Neurology, NYU Langone Health, 222 East 41st Street, 14th Floor, New York, NY, 10016, USA
| | - Matthew R Krause
- Montreal Neurological Institute, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Yu Huang
- Department of Biomedical Engineering, City College of New York, 160 Convent Ave, New York, NY, 10031, USA
| | - Alexander Opitz
- Department of Biomedical Engineering of Minnesota, 312 Church St. SE, Minneapolis, MN, 55455, USA
| | - Ashesh Mehta
- Department of Neurosurgery, Hofstra Northwell School of Medicine, 611 Northern Blvd, Great Neck, NY, 11021, USA
- Feinstein Institute for Medical Research, Hofstra Northwell School of Medicine, 350 Community Drive, Manhasset, NY, 11030, USA
| | - Christopher C Pack
- Montreal Neurological Institute, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Bart Krekelberg
- Center for Molecular and Behavioral Neuroscience, Rutgers University, 197 University Avenue, Newark, NJ, 07102, USA
| | - Antal Berényi
- MTA-SZTE 'Momentum' Oscillatory Neuronal Networks Research Group, Department of Physiology, Faculty of Medicine, University of Szeged, 10 Dom sq., Szeged, H-6720, Hungary
| | - Lucas C Parra
- Department of Biomedical Engineering, City College of New York, 160 Convent Ave, New York, NY, 10031, USA
| | - Lucia Melloni
- New York University Comprehensive Epilepsy Center, 223 34th Street, New York, NY, 10016, USA
- Department of Neurology, NYU Langone Health, 222 East 41st Street, 14th Floor, New York, NY, 10016, USA
- Max Planck Institute for Empirical Aesthetics, Grüneburgweg 14, 60322, Frankfurt am Main, Germany
| | - Orrin Devinsky
- New York University Comprehensive Epilepsy Center, 223 34th Street, New York, NY, 10016, USA
- Department of Neurology, NYU Langone Health, 222 East 41st Street, 14th Floor, New York, NY, 10016, USA
| | - György Buzsáki
- New York University Neuroscience Institute, 435 East 30th Street, New York, NY, 10016, USA.
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62
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Modulation of Motor Learning Capacity by Transcranial Alternating Current Stimulation. Neuroscience 2018; 391:131-139. [DOI: 10.1016/j.neuroscience.2018.09.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/05/2018] [Accepted: 09/10/2018] [Indexed: 11/18/2022]
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63
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Engelen T, Zhan M, Sack AT, de Gelder B. The Influence of Conscious and Unconscious Body Threat Expressions on Motor Evoked Potentials Studied With Continuous Flash Suppression. Front Neurosci 2018; 12:480. [PMID: 30061812 PMCID: PMC6054979 DOI: 10.3389/fnins.2018.00480] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/25/2018] [Indexed: 12/21/2022] Open
Abstract
The observation of threatening expression in others is a strong cue for triggering an action response. One method of capturing such action responses is by measuring the amplitude of motor evoked potentials (MEPs) elicited with single pulse TMS over the primary motor cortex. Indeed, it has been shown that viewing whole body expressions of threat modulate the size of MEP amplitude. Furthermore, emotional cues have been shown to act on certain brain areas even outside of conscious awareness. In the current study, we explored if the influence of viewing whole body expressions of threat extends to stimuli that are presented outside of conscious awareness in healthy participants. To accomplish this, we combined the measurement of MEPs with a continuous flash suppression task. In experiment 1, participants were presented with images of neutral bodies, fearful bodies, or objects that were either perceived consciously or unconsciously, while single pulses of TMS were applied at different times after stimulus onset (200, 500, or 700 ms). In experiment 2 stimuli consisted of neutral bodies, angry bodies or objects, and pulses were applied at either 200 or 400 ms post stimulus onset. In experiment 1, there was a general effect of the time of stimulation, but no condition specific effects were evident. In experiment 2 there were no significant main effects, nor any significant interactions. Future studies need to look into earlier effects of MEP modulation by emotion body stimuli, specifically when presented outside of conscious awareness, as well as an exploration of other outcome measures such as intracortical facilitation.
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Affiliation(s)
| | | | | | - Beatrice de Gelder
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
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Guerra A, Bologna M, Paparella G, Suppa A, Colella D, Di Lazzaro V, Brown P, Berardelli A. Effects of Transcranial Alternating Current Stimulation on Repetitive Finger Movements in Healthy Humans. Neural Plast 2018; 2018:4593095. [PMID: 30123248 PMCID: PMC6079362 DOI: 10.1155/2018/4593095] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/24/2018] [Accepted: 05/23/2018] [Indexed: 02/04/2023] Open
Abstract
Transcranial alternating current stimulation (tACS) is a noninvasive neurophysiological technique that can entrain brain oscillations. Only few studies have investigated the effects of tACS on voluntary movements. We aimed to verify whether tACS, delivered over M1 at beta and gamma frequencies, has any effect on repetitive finger tapping as assessed by means of kinematic analysis. Eighteen healthy subjects were enrolled. Objective measurements of repetitive finger tapping were obtained by using a motion analysis system. M1 excitability was assessed by using single-pulse TMS and measuring the amplitude of motor-evoked potentials (MEPs). Movement kinematic measures and MEPs were collected during beta, gamma, and sham tACS and when the stimulation was off. Beta tACS led to an amplitude decrement (i.e., progressive reduction in amplitude) across the first ten movements of the motor sequence while gamma tACS had the opposite effect. The results did not reveal any significant effect of tACS on other movement parameters, nor any changes in MEPs. These findings demonstrate that tACS modulates finger tapping in a frequency-dependent manner with no concurrent changes in corticospinal excitability. The results suggest that cortical beta and gamma oscillations are involved in the motor control of repetitive finger movements.
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Affiliation(s)
| | - Matteo Bologna
- Neuromed Institute IRCCS, Pozzilli, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Giulia Paparella
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Antonio Suppa
- Neuromed Institute IRCCS, Pozzilli, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Donato Colella
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, University Campus Bio-Medico, Rome, Italy
| | - Peter Brown
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, UK
- Medical Research Council Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
| | - Alfredo Berardelli
- Neuromed Institute IRCCS, Pozzilli, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
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Schilberg L, Engelen T, ten Oever S, Schuhmann T, de Gelder B, de Graaf TA, Sack AT. Phase of beta-frequency tACS over primary motor cortex modulates corticospinal excitability. Cortex 2018; 103:142-152. [DOI: 10.1016/j.cortex.2018.03.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 01/11/2018] [Accepted: 03/01/2018] [Indexed: 01/26/2023]
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Abstract
PURPOSE OF REVIEW This review aims to survey recent trends in electrical forms of neuromodulation, with a specific application to Parkinson's disease (PD). Emerging trends are identified, highlighting synergies in state-of-the-art neuromodulation strategies, with directions for future improvements in stimulation efficacy suggested. RECENT FINDINGS Deep brain stimulation remains the most common and effective form of electrical stimulation for the treatment of PD. Evidence suggests that transcranial direct current stimulation (tDCS) most likely impacts the motor symptoms of the disease, with the most prominent results relating to rehabilitation. However, utility is limited due to its weak effects and high variability, with medication state a key confound for efficacy level. Recent innovations in transcranial alternating current stimulation (tACS) offer new areas for investigation. SUMMARY Our understanding of the mechanistic foundations of electrical current stimulation is advancing and as it does so, trends emerge which steer future clinical trials towards greater efficacy.
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Affiliation(s)
- John-Stuart Brittain
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Hayriye Cagnan
- Institute of Neurology, University College London, London, UK
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67
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Gallasch E, Rafolt D, Postruznik M, Fresnoza S, Christova M. Decrease of motor cortex excitability following exposure to a 20 Hz magnetic field as generated by a rotating permanent magnet. Clin Neurophysiol 2018; 129:1397-1402. [PMID: 29729595 DOI: 10.1016/j.clinph.2018.03.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 02/14/2018] [Accepted: 03/30/2018] [Indexed: 11/18/2022]
Abstract
OBJECTIVES Rotation of a static magnet over the motor cortex (MC) generates a transcranial alternating magnetic field (tAMF), and a linked alternating electrical field. The aim of this transcranial magnetic stimulation (TMS) study is to investigate whether such fields are able to influence MC excitability, and whether there are parallels to tACS induced effects. METHODS Fourteen healthy volunteers received 20 Hz tAMF stimulation over the MC, over the vertex, and 20 Hz tACS over the MC, each with a duration of 15 min. TMS assessments were performed before and after the interventions. Changes in motor evoked potentials (MEP), short interval intra-cortical inhibition (SICI) and intra-cortical facilitation (ICF) were evaluated. RESULTS The tACS and the tAMF stimulation over the MC affected cortical excitability in a different way. After tAMF stimulation MEP amplitudes and ICF decreased and the effect of SICI increased. After tACS MEP amplitudes increased and there were no effects on SICI and ICF. CONCLUSIONS The recorded single and paired pulse MEPs indicate a general decrease of MC excitability following 15 min of tAMF stimulation. SIGNIFICANCE The effects demonstrate that devices based on rotating magnets are potentially suited to become a novel brain stimulation tool in clinical neurophysiology.
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Affiliation(s)
- Eugen Gallasch
- Otto Loewi Research Center, Physiology Section, Medical University of Graz, Austria.
| | - Dietmar Rafolt
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Magdalena Postruznik
- Otto Loewi Research Center, Physiology Section, Medical University of Graz, Austria
| | | | - Monica Christova
- Otto Loewi Research Center, Physiology Section, Medical University of Graz, Austria; Institute of Physiotherapy, University of Applied Sciences FH-Joanneum, Graz, Austria
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Alpha Oscillations Are Causally Linked to Inhibitory Abilities in Ageing. J Neurosci 2018; 38:4418-4429. [PMID: 29615485 DOI: 10.1523/jneurosci.1285-17.2018] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 02/09/2018] [Accepted: 02/13/2018] [Indexed: 11/21/2022] Open
Abstract
Aging adults typically show reduced ability to ignore task-irrelevant information, an essential skill for optimal performance in many cognitive operations, including those requiring working memory (WM) resources. In a first experiment, young and elderly human participants of both genders performed an established WM paradigm probing inhibitory abilities by means of valid, invalid, and neutral retro-cues. Elderly participants showed an overall cost, especially in performing invalid trials, whereas younger participants' general performance was comparatively higher, as expected.Inhibitory abilities have been linked to alpha brain oscillations but it is yet unknown whether in aging these oscillations (also typically impoverished) and inhibitory abilities are causally linked. To probe this possible causal link in aging, we compared in a second experiment parietal alpha-transcranial alternating current stimulation (tACS) with either no stimulation (Sham) or with two control stimulation frequencies (theta- and gamma-tACS) in the elderly group while performing the same WM paradigm. Alpha- (but not theta- or gamma-) tACS selectively and significantly improved performance (now comparable to younger adults' performance in the first experiment), particularly for invalid cues where initially elderly showed the highest costs. Alpha oscillations are therefore causally linked to inhibitory abilities and frequency-tuned alpha-tACS interventions can selectively change these abilities in the elderly.SIGNIFICANCE STATEMENT Ignoring task-irrelevant information, an ability associated to rhythmic brain activity in the alpha frequency band, is fundamental for optimal performance. Indeed, impoverished inhibitory abilities contribute to age-related decline in cognitive functions like working memory (WM), the capacity to briefly hold information in mind. Whether in aging adults alpha oscillations and inhibitory abilities are causally linked is yet unknown. We experimentally manipulated frequency-tuned brain activity using transcranial alternating current stimulation (tACS), combined with a retro-cue paradigm assessing WM and inhibition. We found that alpha-tACS induced a significant improvement in target responses and misbinding errors, two indexes of inhibition. We concluded that in aging alpha oscillations are causally linked to inhibitory abilities, and that despite being impoverished, these abilities are still malleable.
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Guerra A, Suppa A, Bologna M, D'Onofrio V, Bianchini E, Brown P, Di Lazzaro V, Berardelli A. Boosting the LTP-like plasticity effect of intermittent theta-burst stimulation using gamma transcranial alternating current stimulation. Brain Stimul 2018; 11:734-742. [PMID: 29615367 DOI: 10.1016/j.brs.2018.03.015] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/27/2018] [Accepted: 03/22/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Transcranial Alternating Current Stimulation (tACS) consists in delivering electric current to the brain using an oscillatory pattern that may entrain the rhythmic activity of cortical neurons. When delivered at gamma frequency, tACS modulates motor performance and GABA-A-ergic interneuron activity. OBJECTIVE Since interneuronal discharges play a crucial role in brain plasticity phenomena, here we co-stimulated the primary motor cortex (M1) in healthy subjects by means of tACS during intermittent theta-burst stimulation (iTBS), a transcranial magnetic stimulation paradigm known to induce long-term potentiation (LTP)-like plasticity. METHODS We measured and compared motor evoked potentials before and after gamma, beta and sham tACS-iTBS. While we delivered gamma-tACS, we also measured short-interval intracortical inhibition (SICI) to detect any changes in GABA-A-ergic neurotransmission. RESULTS Gamma, but not beta and sham tACS, significantly boosted and prolonged the iTBS-induced after-effects. Interestingly, the extent of the gamma tACS-iTBS after-effects correlated directly with SICI changes. CONCLUSIONS Overall, our findings point to a link between gamma oscillations, interneuronal GABA-A-ergic activity and LTP-like plasticity in the human M1. Gamma tACS-iTBS co-stimulation might represent a new strategy to enhance and prolong responses to plasticity-inducing protocols, thereby lending itself to future applications in the neurorehabilitation setting.
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Affiliation(s)
- Andrea Guerra
- Department of Human Neuroscience, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy
| | - Antonio Suppa
- Department of Human Neuroscience, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy; IRCCS Neuromed Institute, Via Atinense 18, 86077, Pozzilli, IS, Italy
| | - Matteo Bologna
- Department of Human Neuroscience, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy; IRCCS Neuromed Institute, Via Atinense 18, 86077, Pozzilli, IS, Italy
| | - Valentina D'Onofrio
- Department of Human Neuroscience, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy
| | - Edoardo Bianchini
- Department of Human Neuroscience, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy
| | - Peter Brown
- Medical Research Council Brain Network Dynamics Unit and Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 9DU, United Kingdom
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, University Campus Bio-Medico, via Álvaro del Portillo 21, 00128, Rome, Italy
| | - Alfredo Berardelli
- Department of Human Neuroscience, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy; IRCCS Neuromed Institute, Via Atinense 18, 86077, Pozzilli, IS, Italy.
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Zrenner C, Desideri D, Belardinelli P, Ziemann U. Real-time EEG-defined excitability states determine efficacy of TMS-induced plasticity in human motor cortex. Brain Stimul 2018; 11:374-389. [DOI: 10.1016/j.brs.2017.11.016] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 11/19/2017] [Accepted: 11/20/2017] [Indexed: 12/13/2022] Open
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Mineo L, Concerto C, Patel D, Mayorga T, Chusid E, Infortuna C, Aguglia E, Sarraf Y, Battaglia F. Modulation of sensorimotor circuits during retrieval of negative Autobiographical Memories: Exploring the impact of personality dimensions. Neuropsychologia 2018; 110:190-196. [DOI: 10.1016/j.neuropsychologia.2017.04.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 04/01/2017] [Accepted: 04/08/2017] [Indexed: 02/04/2023]
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Turco CV, El-Sayes J, Savoie MJ, Fassett HJ, Locke MB, Nelson AJ. Short- and long-latency afferent inhibition; uses, mechanisms and influencing factors. Brain Stimul 2018; 11:59-74. [DOI: 10.1016/j.brs.2017.09.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 08/28/2017] [Accepted: 09/14/2017] [Indexed: 12/11/2022] Open
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Pinto CB, Saleh Velez FG, Lopes F, de Toledo Piza PV, Dipietro L, Wang QM, Mazwi NL, Camargo EC, Black-Schaffer R, Fregni F. SSRI and Motor Recovery in Stroke: Reestablishment of Inhibitory Neural Network Tonus. Front Neurosci 2017; 11:637. [PMID: 29200995 PMCID: PMC5696576 DOI: 10.3389/fnins.2017.00637] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 11/02/2017] [Indexed: 12/23/2022] Open
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are currently widely used in the field of the neuromodulation not only because of their anti-depressive effects but also due to their ability to promote plasticity and enhance motor recovery in patients with stroke. Recent studies showed that fluoxetine promotes motor recovery after stroke through its effects on the serotonergic system enhancing motor outputs and facilitating long term potentiation, key factors in motor neural plasticity. However, little is known in regards of the exact mechanisms underlying these effects and several aspects of it remain poorly understood. In this manuscript, we discuss evidence supporting the hypothesis that SSRIs, and in particular fluoxetine, modulate inhibitory pathways, and that this modulation enhances reorganization and reestablishment of excitatory-inhibitory control; these effects play a key role in learning induced plasticity in neural circuits involved in the promotion of motor recovery after stroke. This discussion aims to provide important insights and rationale for the development of novel strategies for stroke motor rehabilitation.
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Affiliation(s)
- Camila B. Pinto
- Laboratory of Neuromodulation and Center for Clinical Research Learning, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Harvard University, Boston, MA, United States
- Department of Neuroscience and Behavior, Psychology Institute, University of São Paulo, São Paulo, Brazil
| | - Faddi G. Saleh Velez
- Laboratory of Neuromodulation and Center for Clinical Research Learning, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Harvard University, Boston, MA, United States
| | - Fernanda Lopes
- Laboratory of Neuromodulation and Center for Clinical Research Learning, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Harvard University, Boston, MA, United States
| | - Polyana V. de Toledo Piza
- Laboratory of Neuromodulation and Center for Clinical Research Learning, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Harvard University, Boston, MA, United States
- Department of Severe Patients, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | | | - Qing M. Wang
- Stroke Biological Recovery Laboratory, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Harvard University, Boston, MA, United States
| | - Nicole L. Mazwi
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Harvard University, Boston, MA, United States
| | - Erica C. Camargo
- Department of Neurology, Harvard Medical School, Massachusetts General Hospital, Harvard University, Boston, MA, United States
| | - Randie Black-Schaffer
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Harvard University, Boston, MA, United States
| | - Felipe Fregni
- Laboratory of Neuromodulation and Center for Clinical Research Learning, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, Harvard University, Boston, MA, United States
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Huang YZ, Lu MK, Antal A, Classen J, Nitsche M, Ziemann U, Ridding M, Hamada M, Ugawa Y, Jaberzadeh S, Suppa A, Paulus W, Rothwell J. Plasticity induced by non-invasive transcranial brain stimulation: A position paper. Clin Neurophysiol 2017; 128:2318-2329. [DOI: 10.1016/j.clinph.2017.09.007] [Citation(s) in RCA: 198] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 08/31/2017] [Accepted: 09/05/2017] [Indexed: 12/11/2022]
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Raco V, Bauer R, Norim S, Gharabaghi A. Cumulative effects of single TMS pulses during beta-tACS are stimulation intensity-dependent. Brain Stimul 2017; 10:1055-1060. [DOI: 10.1016/j.brs.2017.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 11/25/2022] Open
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Modulation of Long-Range Connectivity Patterns via Frequency-Specific Stimulation of Human Cortex. Curr Biol 2017; 27:3061-3068.e3. [PMID: 28966091 PMCID: PMC5640151 DOI: 10.1016/j.cub.2017.08.075] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 07/26/2017] [Accepted: 08/30/2017] [Indexed: 12/26/2022]
Abstract
There is increasing interest in how the phase of local oscillatory activity within a brain area determines the long-range functional connectivity of that area. For example, increasing convergent evidence from a range of methodologies suggests that beta (20 Hz) oscillations may play a vital role in the function of the motor system [1, 2, 3, 4, 5]. The “communication through coherence” hypothesis posits that the precise phase of coherent oscillations in network nodes is a determinant of successful communication between them [6, 7]. Here we set out to determine whether oscillatory activity in the beta band serves to support this theory within the cortical motor network in vivo. We combined non-invasive transcranial alternating-current stimulation (tACS) [8, 9, 10, 11, 12] with resting-state functional MRI (fMRI) [13] to follow both changes in local activity and long-range connectivity, determined by inter-areal blood-oxygen-level-dependent (BOLD) signal correlation, as a proxy for communication in the human cortex. Twelve healthy subjects participated in three fMRI scans with 20 Hz, 5 Hz, or sham tACS applied separately on each scan. Transcranial magnetic stimulation (TMS) at beta frequency has previously been shown to increase local activity in the beta band [14] and to modulate long-range connectivity within the default mode network [15]. We demonstrated that beta-frequency tACS significantly changed the connectivity pattern of the stimulated primary motor cortex (M1), without changing overall local activity or network connectivity. This finding is supported by a simple phase-precession model, which demonstrates the plausibility of the results and provides emergent predictions that are consistent with our empirical findings. These findings therefore inform our understanding of how local oscillatory activity may underpin network connectivity. tACS does not alter overall functional connectivity between major network nodes However, tACS modulates the connectivity pattern of the stimulated motor cortex These data directly support the “communication through coherence” hypothesis We provide evidence for how disordered connectivity arises from oscillatory changes
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Fehér KD, Nakataki M, Morishima Y. Phase-Dependent Modulation of Signal Transmission in Cortical Networks through tACS-Induced Neural Oscillations. Front Hum Neurosci 2017; 11:471. [PMID: 29021749 PMCID: PMC5624081 DOI: 10.3389/fnhum.2017.00471] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/08/2017] [Indexed: 11/13/2022] Open
Abstract
Oscillatory neural activity is considered a basis of signal transmission in brain networks. However, the causal role of neural oscillations in regulating cortico-cortical signal transmission has so far not been directly demonstrated. To date, due to methodological limitations, studies on the online modulatory mechanisms of transcranial alternating current stimulation (tACS)-induced neural oscillations are confined to the primary motor cortex. To address the causal role of oscillatory activity in modulating cortico-cortical signal transmission, we have established a new method using concurrent tACS, transcranial magnetic stimulation (TMS) and electroencephalography (EEG). Through tACS, we introduced 6-Hz (theta) oscillatory activity in the human dorsolateral prefrontal cortex (DLPFC). During tACS, we applied single-pulse TMS over the DLPFC at different phases of tACS and assessed propagation of TMS-induced neural activity with EEG. We show that tACS-induced theta oscillations modulate the propagation of TMS-induced activity in a phase-dependent manner and that phase-dependent modulation is not simply explained by the instantaneous amplitude of tACS. The results demonstrate a phase-dependent modulatory mechanism of tACS at a cortical network level, which is consistent with a causal role of neural oscillations in regulating the efficacy of signal transmission in the brain.
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Affiliation(s)
- Kristoffer D. Fehér
- Division of Systems Neuroscience of Psychopathology, Translational Research Centre, University Hospital of Psychiatry, University of Bern, Bern, Switzerland
| | - Masahito Nakataki
- Division of Systems Neuroscience of Psychopathology, Translational Research Centre, University Hospital of Psychiatry, University of Bern, Bern, Switzerland
| | - Yosuke Morishima
- Division of Systems Neuroscience of Psychopathology, Translational Research Centre, University Hospital of Psychiatry, University of Bern, Bern, Switzerland
- PRESTO, Japan Science and Technology Agency, Saitama, Japan
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78
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Shpektor A, Nazarova M, Feurra M. Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation. J Vis Exp 2017. [PMID: 28994763 DOI: 10.3791/55839] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific frequency and in turn modulate ongoing cortical oscillatory activity. This neurotool allows the establishment of a causal link between endogenous oscillatory activity and behavior. Most of the tACS studies have shown online effects of tACS. However, little is known about the underlying action mechanisms of this technique because of the AC-induced artifacts on Electroencephalography (EEG) signals. Here we show a unique approach to investigate online physiological frequency-specific effects of tACS of the primary motor cortex (M1) by using single pulse Transcranial Magnetic Stimulation (TMS) to probe cortical excitability changes. In our setup, the TMS coil is placed over the tACS electrode while Motor Evoked Potentials (MEPs) are collected to test the effects of the ongoing M1-tACS. So far, this approach has mainly been used to study the visual and motor systems. However, the current tACS-TMS setup can pave the way for future investigations of cognitive functions. Therefore, we provide a step-by-step manual and video guidelines for the procedure.
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Affiliation(s)
- Anna Shpektor
- School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics; Department of Experimental Psychology, University of Oxford
| | - Maria Nazarova
- Centre for Cognition and Decision Making, National Research University Higher School of Economics
| | - Matteo Feurra
- School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics; Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, Brain Investigation & Neuromodulation Lab. (Si-BIN Lab), Azienda Ospedaliera Universitaria of Siena;
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79
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Tavakoli AV, Yun K. Transcranial Alternating Current Stimulation (tACS) Mechanisms and Protocols. Front Cell Neurosci 2017; 11:214. [PMID: 28928634 PMCID: PMC5591642 DOI: 10.3389/fncel.2017.00214] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/04/2017] [Indexed: 12/20/2022] Open
Abstract
Perception, cognition and consciousness can be modulated as a function of oscillating neural activity, while ongoing neuronal dynamics are influenced by synaptic activity and membrane potential. Consequently, transcranial alternating current stimulation (tACS) may be used for neurological intervention. The advantageous features of tACS include the biphasic and sinusoidal tACS currents, the ability to entrain large neuronal populations, and subtle control over somatic effects. Through neuromodulation of phasic, neural activity, tACS is a powerful tool to investigate the neural correlates of cognition. The rapid development in this area requires clarity about best practices. Here we briefly introduce tACS and review the most compelling findings in the literature to provide a starting point for using tACS. We suggest that tACS protocols be based on functional brain mechanisms and appropriate control experiments, including active sham and condition blinding.
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Affiliation(s)
- Amir V Tavakoli
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadena, CA, United States.,Department of Psychology, University of California, Los AngelesLos Angeles, CA, United States
| | - Kyongsik Yun
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadena, CA, United States.,Computation and Neural Systems, California Institute of TechnologyPasadena, CA, United States.,Bio-Inspired Technologies and Systems, Jet Propulsion Laboratory, California Institute of TechnologyPasadena, CA, United States
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On the effectiveness of event-related beta tACS on episodic memory formation and motor cortex excitability. Brain Stimul 2017; 10:910-918. [DOI: 10.1016/j.brs.2017.04.129] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 04/18/2017] [Accepted: 04/27/2017] [Indexed: 11/21/2022] Open
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81
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Simultaneously Excitatory and Inhibitory Effects of Transcranial Alternating Current Stimulation Revealed Using Selective Pulse-Train Stimulation in the Rat Motor Cortex. J Neurosci 2017; 37:9389-9402. [PMID: 28847809 DOI: 10.1523/jneurosci.1390-17.2017] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/03/2017] [Accepted: 08/10/2017] [Indexed: 12/13/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) uses sinusoidal, subthreshold, electric fields to modulate cortical processing. Cortical processing depends on a fine balance between excitation and inhibition and tACS acts on both excitatory and inhibitory cortical neurons. Given this, it is not clear whether tACS should increase or decrease cortical excitability. We investigated this using transcranial current stimulation of the rat (all males) motor cortex consisting of a continuous subthreshold sine wave with short bursts of suprathreshold pulse-trains inserted at different phases to probe cortical excitability. We found that when a low-rate, long-duration, suprathreshold pulse-train was used, subthreshold cathodal tACS decreased cortical excitability and anodal tACS increased excitability. However, when a high-rate, short-duration, suprathreshold pulse-train was used this pattern was inverted. An integrate-and-fire model incorporating biophysical differences between cortical excitatory and inhibitory neurons could predict the experimental data and helped interpret these results. The model indicated that low-rate suprathreshold pulse-trains preferentially stimulate excitatory cortical neurons, whereas high-rate suprathreshold pulse-trains stimulate both excitatory and inhibitory neurons. If correct, this indicates that suprathreshold pulse-train stimulation may be able to selectively control the excitation-inhibition balance within a cortical network. The excitation-inhibition balance then likely plays an important role in determining whether subthreshold tACS will increase or decrease cortical excitability.SIGNIFICANCE STATEMENT Transcranial alternating current stimulation (tACS) is a noninvasive neuromodulation method that uses weak sinusoidal electric fields to modulate cortical activity. In healthy volunteers tACS can modulate perception, cognition, and motor function but the underlying neural mechanism is poorly understood. In this study, using rat motor cortex, we found that tACS effects are highly variable: applying the same tACS waveform to the same cortical area does not always give the same change in cortical excitability. An integrate-and-fire model incorporating excitatory pyramidal and inhibitory interneurons indicated that tACS effects likely depend on the cortical excitation-inhibition balance. When cortical activity is excitation dominated one particular tACS phase increases excitability, but when the cortical activity is inhibition dominated the same tACS phase actually decreases excitability.
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82
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Mansouri F, Dunlop K, Giacobbe P, Downar J, Zariffa J. A Fast EEG Forecasting Algorithm for Phase-Locked Transcranial Electrical Stimulation of the Human Brain. Front Neurosci 2017; 11:401. [PMID: 28775678 PMCID: PMC5517498 DOI: 10.3389/fnins.2017.00401] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/27/2017] [Indexed: 12/12/2022] Open
Abstract
A growing body of research suggests that non-invasive electrical brain stimulation can more effectively modulate neural activity when phase-locked to the underlying brain rhythms. Transcranial alternating current stimulation (tACS) can potentially stimulate the brain in-phase to its natural oscillations as recorded by electroencephalography (EEG), but matching these oscillations is a challenging problem due to the complex and time-varying nature of the EEG signals. Here we address this challenge by developing and testing a novel approach intended to deliver tACS phase-locked to the activity of the underlying brain region in real-time. This novel approach extracts phase and frequency from a segment of EEG, then forecasts the signal to control the stimulation. A careful tuning of the EEG segment length and prediction horizon is required and has been investigated here for different EEG frequency bands. The algorithm was tested on EEG data from 5 healthy volunteers. Algorithm performance was quantified in terms of phase-locking values across a variety of EEG frequency bands. Phase-locking performance was found to be consistent across individuals and recording locations. With current parameters, the algorithm performs best when tracking oscillations in the alpha band (8–13 Hz), with a phase-locking value of 0.77 ± 0.08. Performance was maximized when the frequency band of interest had a dominant frequency that was stable over time. The algorithm performs faster, and provides better phase-locked stimulation, compared to other recently published algorithms devised for this purpose. The algorithm is suitable for use in future studies of phase-locked tACS in preclinical and clinical applications.
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Affiliation(s)
- Farrokh Mansouri
- Institute of Biomaterial and Biomedical Engineering, University of TorontoToronto, ON, Canada
| | - Katharine Dunlop
- Institute of Medical Science, University of TorontoToronto, ON, Canada
| | - Peter Giacobbe
- Department of Psychiatry, University of TorontoToronto, ON, Canada.,Centre for Mental Health, University Health NetworkToronto, ON, Canada
| | - Jonathan Downar
- Institute of Medical Science, University of TorontoToronto, ON, Canada.,Department of Psychiatry, University of TorontoToronto, ON, Canada.,Centre for Mental Health, University Health NetworkToronto, ON, Canada.,Krembil Research Institute, University Health NetworkToronto, ON, Canada
| | - José Zariffa
- Institute of Biomaterial and Biomedical Engineering, University of TorontoToronto, ON, Canada.,Toronto Rehabilitation Institute, University Health NetworkToronto, ON, Canada
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83
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Di Lazzaro V, Rothwell J, Capogna M. Noninvasive Stimulation of the Human Brain: Activation of Multiple Cortical Circuits. Neuroscientist 2017; 24:246-260. [DOI: 10.1177/1073858417717660] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Noninvasive brain stimulation methods, such as transcranial electric stimulation and transcranial magnetic stimulation are widely used tools for both basic research and clinical applications. However, the cortical circuits underlying their effects are poorly defined. Here we review the current knowledge based on data mostly coming from experiments performed on human subjects, and also to a lesser extent on rodent or primate models. The data suggest that multiple mechanisms are likely to be involved, such as the direct activation of layer V pyramidal neurons, but also of different types of GABAergic interneurons. In this regard, we propose a key role for a specific type of interneuron known as neurogliaform cell.
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Affiliation(s)
- Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
- Fondazione Alberto Sordi–Research Institute for Ageing, Rome, Italy
| | - John Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK
| | - Marco Capogna
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- The Danish Research Institute of Translational Neuroscience–DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, Aarhus, Denmark
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84
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Giovanni A, Capone F, di Biase L, Ferreri F, Florio L, Guerra A, Marano M, Paolucci M, Ranieri F, Salomone G, Tombini M, Thut G, Di Lazzaro V. Oscillatory Activities in Neurological Disorders of Elderly: Biomarkers to Target for Neuromodulation. Front Aging Neurosci 2017; 9:189. [PMID: 28659788 PMCID: PMC5468377 DOI: 10.3389/fnagi.2017.00189] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 05/26/2017] [Indexed: 12/13/2022] Open
Abstract
Non-invasive brain stimulation (NIBS) has been under investigation as adjunct treatment of various neurological disorders with variable success. One challenge is the limited knowledge on what would be effective neuronal targets for an intervention, combined with limited knowledge on the neuronal mechanisms of NIBS. Motivated on the one hand by recent evidence that oscillatory activities in neural systems play a role in orchestrating brain functions and dysfunctions, in particular those of neurological disorders specific of elderly patients, and on the other hand that NIBS techniques may be used to interact with these brain oscillations in a controlled way, we here explore the potential of modulating brain oscillations as an effective strategy for clinical NIBS interventions. We first review the evidence for abnormal oscillatory profiles to be associated with a range of neurological disorders of elderly (e.g., Parkinson's disease (PD), Alzheimer's disease (AD), stroke, epilepsy), and for these signals of abnormal network activity to normalize with treatment, and/or to be predictive of disease progression or recovery. We then ask the question to what extent existing NIBS protocols have been tailored to interact with these oscillations and possibly associated dysfunctions. Our review shows that, despite evidence for both reliable neurophysiological markers of specific oscillatory dis-functionalities in neurological disorders and NIBS protocols potentially able to interact with them, there are few applications of NIBS aiming to explore clinical outcomes of this interaction. Our review article aims to point out oscillatory markers of neurological, which are also suitable targets for modification by NIBS, in order to facilitate in future studies the matching of technical application to clinical targets.
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Affiliation(s)
- Assenza Giovanni
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | | | - Lazzaro di Biase
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
- Nuffield Department of Clinical Neurosciences, University of OxfordOxford, United Kingdom
| | - Florinda Ferreri
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
- Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern FinlandKuopio, Finland
| | - Lucia Florio
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Andrea Guerra
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
- Nuffield Department of Clinical Neurosciences, University of OxfordOxford, United Kingdom
| | - Massimo Marano
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Matteo Paolucci
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Federico Ranieri
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Gaetano Salomone
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Mario Tombini
- Clinical Neurology, Campus Biomedico University of RomeRome, Italy
| | - Gregor Thut
- Centre for Cognitive Neuroimaging (CCNi), Institute of Neuroscience and Psychology, University of GlasgowGlasgow, United Kingdom
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85
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Hussain SJ, Thirugnanasambandam N. Probing phase- and frequency-dependent characteristics of cortical interneurons using combined transcranial alternating current stimulation and transcranial magnetic stimulation. J Neurophysiol 2017; 117:2085-2087. [PMID: 28228580 DOI: 10.1152/jn.00060.2017] [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: 01/27/2017] [Revised: 02/15/2017] [Accepted: 02/15/2017] [Indexed: 11/22/2022] Open
Abstract
Paired-pulse transcranial magnetic stimulation (TMS) and peripheral stimulation combined with TMS can be used to study cortical interneuronal circuitry. By combining these procedures with concurrent transcranial alternating current stimulation (tACS), Guerra and colleagues recently showed that different cortical interneuronal populations are differentially modulated by the phase and frequency of tACS-imposed oscillations (Guerra A, Pogosyan A, Nowak M, Tan H, Ferreri F, Di Lazzaro V, Brown P. Cerebral Cortex 26: 3977-2990, 2016). This work suggests that different cortical interneuronal populations can be characterized by their phase and frequency dependency. Here we discuss how combining TMS and tACS can reveal the frequency at which cortical interneuronal populations oscillate, the neuronal origins of behaviorally relevant cortical oscillations, and how entraining cortical oscillations could potentially treat brain disorders.
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Affiliation(s)
- Sara J Hussain
- Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland; and
| | - Nivethida Thirugnanasambandam
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
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86
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Varlet M, Wade A, Novembre G, Keller PE. Investigation of the effects of transcranial alternating current stimulation (tACS) on self-paced rhythmic movements. Neuroscience 2017; 350:75-84. [PMID: 28323009 DOI: 10.1016/j.neuroscience.2017.03.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 03/07/2017] [Accepted: 03/09/2017] [Indexed: 11/27/2022]
Abstract
Human rhythmic movements spontaneously entrain to external rhythmic stimuli. Such sensory-motor entrainment can attract movements to different tempi and enhance their efficiency, with potential clinical applications for motor rehabilitation. Here we investigate whether entrainment of self-paced rhythmic movements can be induced via transcranial alternating current stimulation (tACS), which uses alternating currents to entrain spontaneous brain oscillations at specific frequencies. Participants swung a handheld pendulum at their preferred tempo with the right hand while tACS was applied over their left or right primary motor cortex at frequencies equal to their preferred tempo (Experiment 1) or in the alpha (10Hz) and beta (20Hz) ranges (Experiment 2). Given that entrainment generally occurs only if the frequency difference between two rhythms is small, stimulations were delivered at frequencies equal to participants' preferred movement tempo (≈1Hz) and ±12.5% in Experiment 1, and at 10Hz and 20Hz, and ±12.5% in Experiment 2. The comparison of participants' movement frequency, amplitude, variability, and phase synchrony with and without tACS failed to reveal entrainment or movement modifications across the two experiments. However, significant differences in stimulation-related side effects reported by participants were found between the two experiments, with phosphenes and burning sensations principally occurring in Experiment 2, and metallic tastes reported marginally more often in Experiment 1. Although other stimulation protocols may be effective, our results suggest that rhythmic movements such as pendulum swinging or locomotion that are low in goal-directedness and/or strongly driven by peripheral and mechanical constraints may not be susceptible to modulation by tACS.
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Affiliation(s)
- Manuel Varlet
- The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Australia.
| | - Alanna Wade
- The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Australia
| | - Giacomo Novembre
- The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Australia; Department of Neuroscience, Physiology, and Pharmacology, University College London, United Kingdom
| | - Peter E Keller
- The MARCS Institute for Brain, Behaviour and Development, Western Sydney University, Australia
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87
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Ferreri F, Vecchio F, Guerra A, Miraglia F, Ponzo D, Vollero L, Iannello G, Maatta S, Mervaala E, Rossini PM, Di Lazzaro V. Age related differences in functional synchronization of EEG activity as evaluated by means of TMS-EEG coregistrations. Neurosci Lett 2017; 647:141-146. [DOI: 10.1016/j.neulet.2017.03.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 02/23/2017] [Accepted: 03/13/2017] [Indexed: 11/16/2022]
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88
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Driving Human Motor Cortical Oscillations Leads to Behaviorally Relevant Changes in Local GABA A Inhibition: A tACS-TMS Study. J Neurosci 2017; 37:4481-4492. [PMID: 28348136 PMCID: PMC5413186 DOI: 10.1523/jneurosci.0098-17.2017] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 03/02/2017] [Accepted: 03/08/2017] [Indexed: 12/23/2022] Open
Abstract
Beta and gamma oscillations are the dominant oscillatory activity in the human motor cortex (M1). However, their physiological basis and precise functional significance remain poorly understood. Here, we used transcranial magnetic stimulation (TMS) to examine the physiological basis and behavioral relevance of driving beta and gamma oscillatory activity in the human M1 using transcranial alternating current stimulation (tACS). tACS was applied using a sham-controlled crossover design at individualized intensity for 20 min and TMS was performed at rest (before, during, and after tACS) and during movement preparation (before and after tACS). We demonstrated that driving gamma frequency oscillations using tACS led to a significant, duration-dependent decrease in local resting-state GABAA inhibition, as quantified by short interval intracortical inhibition. The magnitude of this effect was positively correlated with the magnitude of GABAA decrease during movement preparation, when gamma activity in motor circuitry is known to increase. In addition, gamma tACS-induced change in GABAA inhibition was closely related to performance in a motor learning task such that subjects who demonstrated a greater increase in GABAA inhibition also showed faster short-term learning. The findings presented here contribute to our understanding of the neurophysiological basis of motor rhythms and suggest that tACS may have similar physiological effects to endogenously driven local oscillatory activity. Moreover, the ability to modulate local interneuronal circuits by tACS in a behaviorally relevant manner provides a basis for tACS as a putative therapeutic intervention.SIGNIFICANCE STATEMENT Gamma oscillations have a vital role in motor control. Using a combined tACS-TMS approach, we demonstrate that driving gamma frequency oscillations modulates GABAA inhibition in the human motor cortex. Moreover, there is a clear relationship between the change in magnitude of GABAA inhibition induced by tACS and the magnitude of GABAA inhibition observed during task-related synchronization of oscillations in inhibitory interneuronal circuits, supporting the hypothesis that tACS engages endogenous oscillatory circuits. We also show that an individual's physiological response to tACS is closely related to their ability to learn a motor task. These findings contribute to our understanding of the neurophysiological basis of motor rhythms and their behavioral relevance and offer the possibility of developing tACS as a therapeutic tool.
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89
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Espenhahn S, de Berker AO, van Wijk BCM, Rossiter HE, Ward NS. Movement-related beta oscillations show high intra-individual reliability. Neuroimage 2017; 147:175-185. [PMID: 27965146 PMCID: PMC5315054 DOI: 10.1016/j.neuroimage.2016.12.025] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/10/2016] [Accepted: 12/09/2016] [Indexed: 12/31/2022] Open
Abstract
Oscillatory activity in the beta frequency range (15-30Hz) recorded from human sensorimotor cortex is of increasing interest as a putative biomarker of motor system function and dysfunction. Despite its increasing use in basic and clinical research, surprisingly little is known about the test-retest reliability of spectral power and peak frequency measures of beta oscillatory signals from sensorimotor cortex. Establishing that these beta measures are stable over time in healthy populations is a necessary precursor to their use in the clinic. Here, we used scalp electroencephalography (EEG) to evaluate intra-individual reliability of beta-band oscillations over six sessions, focusing on changes in beta activity during movement (Movement-Related Beta Desynchronization, MRBD) and after movement termination (Post-Movement Beta Rebound, PMBR). Subjects performed visually-cued unimanual wrist flexion and extension. We assessed Intraclass Correlation Coefficients (ICC) and between-session correlations for spectral power and peak frequency measures of movement-related and resting beta activity. Movement-related and resting beta power from both sensorimotor cortices was highly reliable across sessions. Resting beta power yielded highest reliability (average ICC=0.903), followed by MRBD (average ICC=0.886) and PMBR (average ICC=0.663). Notably, peak frequency measures yielded lower ICC values compared to the assessment of spectral power, particularly for movement-related beta activity (ICC=0.386-0.402). Our data highlight that power measures of movement-related beta oscillations are highly reliable, while corresponding peak frequency measures show greater intra-individual variability across sessions. Importantly, our finding that beta power estimates show high intra-individual reliability over time serves to validate the notion that these measures reflect meaningful individual differences that can be utilised in basic research and clinical studies.
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Affiliation(s)
- Svenja Espenhahn
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, 33 Queen Square, WC1N 3BG London, UK.
| | - Archy O de Berker
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, 33 Queen Square, WC1N 3BG London, UK; Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, WC1N 3BG London, UK
| | - Bernadette C M van Wijk
- Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, WC1N 3BG London, UK; Department of Neurology, Charité University Medicine, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Holly E Rossiter
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Maindy Road, CF24 4HQ Cardiff, UK
| | - Nick S Ward
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, 33 Queen Square, WC1N 3BG London, UK
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90
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Thut G, Bergmann TO, Fröhlich F, Soekadar SR, Brittain JS, Valero-Cabré A, Sack AT, Miniussi C, Antal A, Siebner HR, Ziemann U, Herrmann CS. Guiding transcranial brain stimulation by EEG/MEG to interact with ongoing brain activity and associated functions: A position paper. Clin Neurophysiol 2017; 128:843-857. [PMID: 28233641 DOI: 10.1016/j.clinph.2017.01.003] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 12/10/2016] [Accepted: 01/08/2017] [Indexed: 01/31/2023]
Abstract
Non-invasive transcranial brain stimulation (NTBS) techniques have a wide range of applications but also suffer from a number of limitations mainly related to poor specificity of intervention and variable effect size. These limitations motivated recent efforts to focus on the temporal dimension of NTBS with respect to the ongoing brain activity. Temporal patterns of ongoing neuronal activity, in particular brain oscillations and their fluctuations, can be traced with electro- or magnetoencephalography (EEG/MEG), to guide the timing as well as the stimulation settings of NTBS. These novel, online and offline EEG/MEG-guided NTBS-approaches are tailored to specifically interact with the underlying brain activity. Online EEG/MEG has been used to guide the timing of NTBS (i.e., when to stimulate): by taking into account instantaneous phase or power of oscillatory brain activity, NTBS can be aligned to fluctuations in excitability states. Moreover, offline EEG/MEG recordings prior to interventions can inform researchers and clinicians how to stimulate: by frequency-tuning NTBS to the oscillation of interest, intrinsic brain oscillations can be up- or down-regulated. In this paper, we provide an overview of existing approaches and ideas of EEG/MEG-guided interventions, and their promises and caveats. We point out potential future lines of research to address challenges.
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Affiliation(s)
- Gregor Thut
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK.
| | - Til Ole Bergmann
- Department of Neurology & Stroke, and Hertie Institute for Clinical Brain Research, Institute for Medical Psychology and Behavioral Neurobiology, University Hospital Tübingen, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Flavio Fröhlich
- Department of Psychiatry & Department of Biomedical Engineering & Department of Cell Biology and Physiology & Neuroscience Center & Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Surjo R Soekadar
- Applied Neurotechnology Lab, Department of Psychiatry and Psychotherapy & MEG Center, University Hospital of Tübingen, Tübingen, Germany
| | - John-Stuart Brittain
- Nuffield Department of Clinical Neurosciences, Charles Wolfson Neuroscience Clinical Research Facility, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Antoni Valero-Cabré
- Cerebral Dynamics, Plasticity and Rehabilitation Group, Frontlab, Institut du Cerveau et la Moelle (ICM), CNRS UMR 7225-INSERM U-117, Université Pierre et Marie Curie, Paris, France
| | - Alexander T Sack
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Carlo Miniussi
- Center for Mind/Brain Sciences CIMeC University of Trento, Rovereto, Italy & Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Andrea Antal
- Department of Clinical Neurophysiology, University Medical Center, Göttingen, Germany
| | - Hartwig Roman Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
| | - Ulf Ziemann
- Department of Neurology & Stroke, and Hertie Institute for Clinical Brain Research, University Tübingen, Tübingen, Germany
| | - Christoph S Herrmann
- Experimental Psychology Lab, Department of Psychology, Center for Excellence "Hearing4all", European Medical School, Carl von Ossietzky University & Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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91
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Novembre G, Knoblich G, Dunne L, Keller PE. Interpersonal synchrony enhanced through 20 Hz phase-coupled dual brain stimulation. Soc Cogn Affect Neurosci 2017; 12:nsw172. [PMID: 28119510 PMCID: PMC5390732 DOI: 10.1093/scan/nsw172] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 10/25/2016] [Accepted: 11/24/2016] [Indexed: 11/16/2022] Open
Abstract
Synchronous movement is a key component of social behaviour in several species including humans. Recent theories have suggested a link between interpersonal synchrony of brain oscillations and interpersonal movement synchrony. The present study investigated this link. Using transcranial alternating current stimulation (tACS) applied over the left motor cortex, we induced beta band (20 Hz) oscillations in pairs of individuals who both performed a finger-tapping task with the right hand. In-phase or anti-phase oscillations were delivered during a preparatory period prior to movement and while the tapping task was performed. In-phase 20 Hz stimulation enhanced interpersonal movement synchrony, compared to anti-phase or sham stimulation, particularly for the initial taps following the preparatory period. This was confirmed in an analysis comparing real vs. pseudo pair surrogate data. No enhancement was observed for stimulation frequencies of 2 Hz (matching the target movement frequency) or 10 Hz (alpha band). Thus, phase-coupling of beta band neural oscillations across two individuals' (resting) motor cortices supports the interpersonal alignment of sensorimotor processes that regulate rhythmic action initiation, thereby facilitating the establishment of synchronous movement. Phase-locked dual brain stimulation provides a promising method to study causal effects of interpersonal brain synchrony on social, sensorimotor and cognitive processes.
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Affiliation(s)
- Giacomo Novembre
- The MARCS Institute for Brain, Behavior and Development, Western Sydney University, Australia.
| | - Günther Knoblich
- Department of Cognitive Science, Central European University, Budapest, Hungary
| | - Laura Dunne
- The MARCS Institute for Brain, Behavior and Development, Western Sydney University, Australia
| | - Peter E Keller
- The MARCS Institute for Brain, Behavior and Development, Western Sydney University, Australia
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