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Rosenthal A, Haslacher D, Garbusow M, Pangratz L, Apfel B, Soekadar S, Romanczuk-Seiferth N, Beck A. Neuromodulation and mindfulness as therapeutic treatment in detoxified patients with alcohol use disorder. BMC Psychiatry 2024; 24:635. [PMID: 39334026 PMCID: PMC11438385 DOI: 10.1186/s12888-024-06085-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 09/14/2024] [Indexed: 09/30/2024] Open
Abstract
BACKGROUND Alcohol use disorder (AUD) poses a significant global health challenge. Traditional management strategies often face high relapse rates, leading to a need for innovative approaches. Mindfulness-based relapse prevention (MBRP) has emerged as a promising intervention to enhance cognitive control, reduce cue-related craving and improve interoceptive processing. Neuroimaging studies suggest that mindfulness training can modulate brain networks associated with these factors, potentially improving treatment outcomes for AUD. Neuroimaging studies suggest that mindfulness training can modulate brain networks linked to these brain functions, potentially improving treatment outcomes for AUD. However, it is unclear how MBRP links to neurophysiological measures such as frontal midline theta oscillations (FMΘ) and whether the beneficial effects of MBRP can be increased by enhancing FMΘ. Here, we will use two different forms of neuromodulation to target and enhance these oscillations, and evaluate their impact on the effectiveness of MBRP. METHODS This study will employ a four-arm randomized controlled trial to evaluate the synergistic effects of MBRP augmented with transcutaneous vagus nerve stimulation (tVNS) or closed-loop amplitude-modulated transcranial alternating current stimulation (CLAM-tACS) on cognitive control, cue reactivity and interoceptive processing in AUD patients. Participants will undergo six weekly group MBRP sessions and daily individual mindfulness practices. Assessments will include an inhibition task, cue-induced craving task, and heartbeat discrimination task, alongside heart rate variability and 32-channel EEG recordings. Participants will be assessed pre and post treatment, with a three-month follow-up to evaluate long-term effects on abstinence and alcohol consumption. DISCUSSION This study will not only elucidate the causal link between FMΘ and efficacy of MBRP, but contribute to a better understanding of how combined psychological and neuromodulation interventions can improve treatment outcomes for AUD, potentially leading to more effective therapeutic strategies. This study also seeks to explore individual differences in response to treatment, which could inform future approaches to AUD management. TRIAL REGISTRATION This study received approval by the Charité-Universitätsmedizin Berlin Institutional Review Board (EA1/030/23, 10.11.2023). It was registered on ClinicalTrials.gov (NCT06308484).
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Affiliation(s)
- Annika Rosenthal
- Institute for Mental Health and Behavioral Medicine, Department of Psychology, HMU Health and Medical University Potsdam, 14471, Potsdam, Germany.
- Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Campus Charité Mitte, 10117, Berlin, Germany.
| | - D Haslacher
- Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Campus Charité Mitte, 10117, Berlin, Germany
| | - M Garbusow
- Department of Psychology, MSB Medical School Berlin, 14197, Berlin, Germany
| | - L Pangratz
- Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Campus Charité Mitte, 10117, Berlin, Germany
| | - B Apfel
- Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Campus Charité Mitte, 10117, Berlin, Germany
| | - S Soekadar
- Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Campus Charité Mitte, 10117, Berlin, Germany
| | | | - A Beck
- Department of Psychiatry and Neurosciences, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Campus Charité Mitte, 10117, Berlin, Germany
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Haslacher D, Cavallo A, Reber P, Kattein A, Thiele M, Nasr K, Hashemi K, Sokoliuk R, Thut G, Soekadar SR. Working memory enhancement using real-time phase-tuned transcranial alternating current stimulation. Brain Stimul 2024; 17:850-859. [PMID: 39029737 DOI: 10.1016/j.brs.2024.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 07/02/2024] [Accepted: 07/12/2024] [Indexed: 07/21/2024] Open
Abstract
BACKGROUND Prior work has shown that transcranial alternating current stimulation (tACS) of parietooccipital alpha oscillations (8-14 Hz) can modulate working memory (WM) performance as a function of the phase lag to endogenous oscillations. However, leveraging this effect using real-time phase-tuned tACS has not been feasible so far due to stimulation artifacts preventing continuous phase tracking. OBJECTIVES AND HYPOTHESIS We aimed to develop a system that tracks and adapts the phase lag between tACS and ongoing parietooccipital alpha oscillations in real-time. We hypothesized that such real-time phase-tuned tACS enhances working memory performance, depending on the phase lag. METHODS We developed real-time phase-tuned closed-loop amplitude-modulated tACS (CLAM-tACS) targeting parietooccipital alpha oscillations. CLAM-tACS was applied at six different phase lags relative to ongoing alpha oscillations while participants (N = 21) performed a working memory task. To exclude that behavioral effects of CLAM-tACS were mediated by other factors such as sensory co-stimulation, a second group of participants (N = 25) received equivalent stimulation of the forehead. RESULTS WM accuracy improved in a phase lag dependent manner (p = 0.0350) in the group receiving parietooccipital stimulation, with the strongest enhancement observed at 330° phase lag between tACS and ongoing alpha oscillations (p = 0.00273, d = 0.976). Moreover, across participants, modulation of frontoparietal alpha oscillations correlated both in amplitude (p = 0.0248) and phase (p = 0.0270) with the modulation of WM accuracy. No such effects were observed in the control group receiving frontal stimulation. CONCLUSIONS Our results demonstrate the feasibility and efficacy of real-time phase-tuned CLAM-tACS in modulating both brain activity and behavior, thereby paving the way for further investigation into brain-behavior relationships and the exploration of innovative therapeutic applications.
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Affiliation(s)
- David Haslacher
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Alessia Cavallo
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany; Department of Neurology and Experimental Neurology, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Philipp Reber
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany; Department of Psychology, University of California, Berkeley, CA, USA
| | - Anna Kattein
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Moritz Thiele
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Khaled Nasr
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Kimia Hashemi
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Rodika Sokoliuk
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Gregor Thut
- School of Psychology & Neuroscience, University of Glasgow, Glasgow, UK
| | - Surjo R Soekadar
- Clinical Neurotechnology Laboratory, Department of Psychiatry and Neurosciences, Charité Campus Mitte, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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Meltzer JA, Sivaratnam G, Deschamps T, Zadeh M, Li C, Farzan F, Francois-Nienaber A. Contrasting MEG effects of anodal and cathodal high-definition TDCS on sensorimotor activity during voluntary finger movements. FRONTIERS IN NEUROIMAGING 2024; 3:1341732. [PMID: 38379832 PMCID: PMC10875011 DOI: 10.3389/fnimg.2024.1341732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/15/2024] [Indexed: 02/22/2024]
Abstract
Introduction Protocols for noninvasive brain stimulation (NIBS) are generally categorized as "excitatory" or "inhibitory" based on their ability to produce short-term modulation of motor-evoked potentials (MEPs) in peripheral muscles, when applied to motor cortex. Anodal and cathodal stimulation are widely considered excitatory and inhibitory, respectively, on this basis. However, it is poorly understood whether such polarity-dependent changes apply for neural signals generated during task performance, at rest, or in response to sensory stimulation. Methods To characterize such changes, we measured spontaneous and movement-related neural activity with magnetoencephalography (MEG) before and after high-definition transcranial direct-current stimulation (HD-TDCS) of the left motor cortex (M1), while participants performed simple finger movements with the left and right hands. Results Anodal HD-TDCS (excitatory) decreased the movement-related cortical fields (MRCF) localized to left M1 during contralateral right finger movements while cathodal HD-TDCS (inhibitory), increased them. In contrast, oscillatory signatures of voluntary motor output were not differentially affected by the two stimulation protocols, and tended to decrease in magnitude over the course of the experiment regardless. Spontaneous resting state oscillations were not affected either. Discussion MRCFs are thought to reflect reafferent proprioceptive input to motor cortex following movements. Thus, these results suggest that processing of incoming sensory information may be affected by TDCS in a polarity-dependent manner that is opposite that seen for MEPs-increases in cortical excitability as defined by MEPs may correspond to reduced responses to afferent input, and vice-versa.
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Affiliation(s)
- Jed A. Meltzer
- Rotman Research Institute, Baycrest Academy for Research and Education, Toronto, ON, Canada
- Departments of Psychology and Speech-language Pathology, University of Toronto, Toronto, ON, Canada
| | - Gayatri Sivaratnam
- Rotman Research Institute, Baycrest Academy for Research and Education, Toronto, ON, Canada
| | - Tiffany Deschamps
- Rotman Research Institute, Baycrest Academy for Research and Education, Toronto, ON, Canada
| | - Maryam Zadeh
- Rotman Research Institute, Baycrest Academy for Research and Education, Toronto, ON, Canada
| | - Catherine Li
- Rotman Research Institute, Baycrest Academy for Research and Education, Toronto, ON, Canada
| | - Faranak Farzan
- School of Mechatronic Systems Engineering, Simon Fraser University, Burnaby, BC, Canada
| | - Alex Francois-Nienaber
- Rotman Research Institute, Baycrest Academy for Research and Education, Toronto, ON, Canada
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Shirota Y, Fushimi M, Sekino M, Yumoto M. Investigating the technical feasibility of magnetoencephalography during transcranial direct current stimulation. Front Hum Neurosci 2023; 17:1270605. [PMID: 37771350 PMCID: PMC10525331 DOI: 10.3389/fnhum.2023.1270605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 08/28/2023] [Indexed: 09/30/2023] Open
Abstract
Introduction Magnetoencephalography (MEG) can measure weak magnetic fields produced by electrical brain activity. Transcranial direct current stimulation (tDCS) can affect such brain activities. The concurrent application of both, however, is challenging because tDCS presents artifacts on the MEG signal. If brain activity during tDCS can be elucidated by MEG, mechanisms of plasticity-inducing and other effects of tDCS would be more comprehensively understood. We tested the technical feasibility of MEG during tDCS using a phantom that produces an artificial current dipole simulating focal brain activity. An earlier study investigated estimation of a single oscillating phantom dipole during tDCS, and we systematically tested multiple dipole locations with a different MEG device. Methods A phantom provided by the manufacturer was used to produce current dipoles from 32 locations. For the 32 dipoles, MEG was recorded with and without tDCS. Temporally extended signal space separation (tSSS) was applied for artifact rejection. Current dipole sources were estimated as equivalent current dipoles (ECDs). The ECD modeling quality was assessed using localization error, amplitude error, and goodness of fit (GOF). The ECD modeling performance with and without tDCS, and with and without tSSS was assessed. Results Mean localization errors of the 32 dipoles were 1.70 ± 0.72 mm (tDCS off, tSSS off, mean ± standard deviation), 6.13 ± 3.32 mm (tDCS on, tSSS off), 1.78 ± 0.83 mm (tDCS off, tSSS on), and 5.73 ± 1.60 mm (tDCS on, tSSS on). Mean GOF findings were, respectively, 92.3, 87.4, 97.5, and 96.7%. Modeling was affected by tDCS and restored by tSSS, but improvement of the localization error was marginal, even with tSSS. Also, the quality was dependent on the dipole location. Discussion Concurrent tDCS-MEG recording is feasible, especially when tSSS is applied for artifact rejection and when the assumed location of the source of activity is favorable for modeling. More technical studies must be conducted to confirm its feasibility with different source modeling methods and stimulation protocols. Recovery of single-trial activity under tDCS warrants further research.
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Affiliation(s)
- Yuichiro Shirota
- Department of Clinical Laboratory, The University of Tokyo Hospital, Tokyo, Japan
| | - Motofumi Fushimi
- Department of Bioengineering, The Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Masaki Sekino
- Department of Bioengineering, The Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Masato Yumoto
- Department of Clinical Laboratory, The University of Tokyo Hospital, Tokyo, Japan
- Department of Clinical Engineering, Gunma Paz University, Takasaki, Japan
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Haslacher D, Narang A, Sokoliuk R, Cavallo A, Reber P, Nasr K, Santarnecchi E, Soekadar SR. In vivo phase-dependent enhancement and suppression of human brain oscillations by transcranial alternating current stimulation (tACS). Neuroimage 2023:120187. [PMID: 37230205 DOI: 10.1016/j.neuroimage.2023.120187] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 05/21/2023] [Accepted: 05/22/2023] [Indexed: 05/27/2023] Open
Abstract
Transcranial alternating current stimulation (tACS) can influence perception and behavior, with recent evidence also highlighting its potential impact in clinical settings, but its underlying mechanisms are poorly understood. Behavioral and indirect physiological evidence indicates that phase-dependent constructive and destructive interference between the applied electric field and brain oscillations at the stimulation frequency may play an important role, but in vivo validation during stimulation was unfeasible because stimulation artifacts impede single-trial assessment of brain oscillations during tACS. Here, we attenuated stimulation artifacts to provide evidence for phase-dependent enhancement and suppression of visually evoked steady state responses (SSR) during amplitude-modulated tACS (AM-tACS). We found that AM-tACS enhanced and suppressed SSR by 5.77 ± 2.95 %, while it enhanced and suppressed corresponding visual perception by 7.99 ± 5.15 %. While not designed to investigate the underlying mechanisms of this effect, our study suggests feasibility and superiority of phase-locked (closed-loop) AM-tACS over conventional (open-loop) AM-tACS to purposefully enhance or suppress brain oscillations at specific frequencies.
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Affiliation(s)
- David Haslacher
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Asmita Narang
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Rodika Sokoliuk
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Alessia Cavallo
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Philipp Reber
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Khaled Nasr
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Emiliano Santarnecchi
- Precision Neuroscience and Neuromodulation Program & Network Control Laboratory, Gordon Center for Medical Imaging, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA
| | - Surjo R Soekadar
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany..
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Nasr K, Haslacher D, Dayan E, Censor N, Cohen LG, Soekadar SR. Breaking the boundaries of interacting with the human brain using adaptive closed-loop stimulation. Prog Neurobiol 2022; 216:102311. [PMID: 35750290 DOI: 10.1016/j.pneurobio.2022.102311] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 06/20/2022] [Indexed: 11/18/2022]
Abstract
The human brain is arguably one of the most complex systems in nature. To understand how it operates, it is essential to understand the link between neural activity and behavior. Experimental investigation of that link requires tools to interact with neural activity during behavior. Human neuroscience, however, has been severely bottlenecked by the limitations of these tools. While invasive methods can support highly specific interaction with brain activity during behavior, their applicability in human neuroscience is limited. Despite extensive development in the last decades, noninvasive alternatives have lacked spatial specificity and yielded results that are commonly fraught with variability and replicability issues, along with relatively limited understanding of the neural mechanisms involved. Here we provide a comprehensive review of the state-of-the-art in interacting with human brain activity and highlight current limitations and recent efforts to overcome these limitations. Beyond crucial technical and scientific advancements in electromagnetic brain stimulation, new frontiers in interacting with human brain activity such as task-irrelevant sensory stimulation and focal ultrasound stimulation are introduced. Finally, we argue that, along with technological improvements and breakthroughs in noninvasive methods, a paradigm shift towards adaptive closed-loop stimulation will be a critical step for advancing human neuroscience.
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Affiliation(s)
- Khaled Nasr
- Clinical Neurotechnology Laboratory & Center for Translational Neuromodulation, Department of Psychiatry and Neurosciences, Charité Campus Mitte (CCM), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - David Haslacher
- Clinical Neurotechnology Laboratory & Center for Translational Neuromodulation, Department of Psychiatry and Neurosciences, Charité Campus Mitte (CCM), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Eran Dayan
- Department of Radiology and Biomedical Research Imaging Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Nitzan Censor
- School of Psychological Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Leonardo G Cohen
- Human Cortical Physiology and Neurorehabilitation Section, National Institutes of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA
| | - Surjo R Soekadar
- Clinical Neurotechnology Laboratory & Center for Translational Neuromodulation, Department of Psychiatry and Neurosciences, Charité Campus Mitte (CCM), Charité - Universitätsmedizin Berlin, Berlin, Germany.
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7
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Theta and gamma oscillatory dynamics in mouse models of Alzheimer's disease: A path to prospective therapeutic intervention. Neurosci Biobehav Rev 2022; 136:104628. [PMID: 35331816 DOI: 10.1016/j.neubiorev.2022.104628] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/09/2022] [Accepted: 03/15/2022] [Indexed: 12/26/2022]
Abstract
Understanding the neural basis of cognitive deficits, a key feature of Alzheimer's disease (AD), is imperative for achieving the therapy of the disease. Rhythmic oscillatory activities in neural systems are a fundamental mechanism for diverse brain functions, including cognition. In several neurological conditions like AD, aberrant neural oscillations have been shown to play a central role. Furthermore, manipulation of brain oscillations in animals has confirmed their impact on cognition and disease. In this article, we review the evidence from mouse models that shows how synchronized oscillatory activity is intricately linked to AD machinery. We primarily focus on recent reports showing abnormal oscillatory activities at theta and gamma frequencies in AD condition and their influence on cellular disturbances and cognitive impairments. A thorough comprehension of the role that neuronal oscillations play in AD pathology should pave the way to therapeutic interventions that can curb the disease.
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Amplitude modulated transcranial alternating current stimulation (AM-TACS) efficacy evaluation via phosphene induction. Sci Rep 2021; 11:22245. [PMID: 34782626 PMCID: PMC8593032 DOI: 10.1038/s41598-021-01482-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/18/2021] [Indexed: 12/01/2022] Open
Abstract
Amplitude modulated transcranial alternating current stimulation (AM-tACS) is a novel method of electrostimulation which enables the recording of electrophysiological signals during stimulation, thanks to an easier removable stimulation artefact compared to classical electrostimulation methods. To gauge the neuromodulatory potential of AM-tACS, we tested its capacity to induce phosphenes as an indicator of stimulation efficacy. AM-tACS was applied via a two-electrode setup, attached on FpZ and below the right eye. AM-tACS waveforms comprised of different carrier (50 Hz, 200 Hz, 1000 Hz) and modulation frequencies (8 Hz, 16 Hz, 28 Hz) were administered with at maximum 2 mA peak-to-peak stimulation strength. TACS conditions in the same frequencies were used as a benchmark for phosphene induction. AM-tACS conditions using a 50 Hz carrier frequency were able to induce phosphenes, but with no difference in phosphene thresholds between modulation frequencies. AM-tACS using a 200 Hz or 1000 Hz carrier frequency did not induce phosphenes. TACS conditions induced phosphenes in line with previous studies. Stimulation effects of AM-tACS conditions were independent of amplitude modulation and instead relied solely on the carrier frequency. A possible explanation may be that AM-tACS needs higher stimulation intensities for its amplitude modulation to have a neuromodulatory effect.
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Haslacher D, Nasr K, Robinson SE, Braun C, Soekadar SR. A set of electroencephalographic (EEG) data recorded during amplitude-modulated transcranial alternating current stimulation (AM-tACS) targeting 10-Hz steady-state visually evoked potentials (SSVEP). Data Brief 2021; 36:107011. [PMID: 33948453 PMCID: PMC8080469 DOI: 10.1016/j.dib.2021.107011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/11/2021] [Accepted: 03/23/2021] [Indexed: 11/25/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) can affect perception, learning and cognition, but the underlying mechanisms are not well understood. A promising strategy to elucidate these mechanisms aims at applying tACS while electric or magnetic brain oscillations targeted by stimulation are recorded. However, reconstructing brain oscillations targeted by tACS remains a challenging problem due to stimulation artifacts. Besides lack of an established strategy to effectively supress such stimulation artifacts, there are also no resources available that allow for the development and testing of new and effective tACS artefact suppression algorithms, such as adaptive spatial filtering using beamforming or signal-space projection. Here, we provide a full dataset comprising encephalographic (EEG) recordings across six healthy human volunteers who underwent 10-Hz amplitude-modulated tACS (AM-tACS) during a 10-Hz steady-state visually evoked potential (SSVEP) paradigm. Moreover, data and scripts are provided related to the validation of a novel stimulation artefact suppression strategy, Stimulation Artifact Source Separation (SASS), removing EEG signal components that are maximally different in the presence versus absence of stimulation. Besides including EEG single-trial data and comparisons of 10-Hz brain oscillatory phase and amplitude recorded across three conditions (condition 1: no stimulation, condition 2: stimulation with SASS, condition 3: stimulation without SASS), also power spectra and topographies of SSVEP amplitudes across all three conditions are presented. Moreover, data is provided for assessing nonlinear modulations of the stimulation artifact in both time and frequency domains due to heartbeats. Finally, the dataset includes eigenvalue spectra and spatial patterns of signal components that were identified and removed by SASS for stimulation artefact suppression at the target frequency. Besides providing a valuable resource to assess properties of AM-tACS artifacts in the EEG, this dataset allows for testing different artifact rejection methods and offers in-depth insights into the workings of SASS.
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Affiliation(s)
- David Haslacher
- Clinical Neurotechnology Laboratory, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité-University Medicine Berlin, Berlin, Germany
| | - Khaled Nasr
- Clinical Neurotechnology Laboratory, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité-University Medicine Berlin, Berlin, Germany
| | - Stephen E. Robinson
- National Institute of Mental Health (NIMH), MEG Core Facility, Bethesda, United States
| | - Christoph Braun
- MEG Center, University of Tübingen, Germany
- CIMeC, Center of Mind/Brain Sciences, University of Trento, Italy
| | - Surjo R. Soekadar
- Clinical Neurotechnology Laboratory, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité-University Medicine Berlin, Berlin, Germany
- Corresponding author. @ssoekadar
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10
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Haslacher D, Nasr K, Robinson SE, Braun C, Soekadar SR. Stimulation artifact source separation (SASS) for assessing electric brain oscillations during transcranial alternating current stimulation (tACS). Neuroimage 2021; 228:117571. [PMID: 33412281 PMCID: PMC7903161 DOI: 10.1016/j.neuroimage.2020.117571] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/11/2020] [Accepted: 11/12/2020] [Indexed: 12/11/2022] Open
Abstract
Stimulation Artifact Source Separation (SASS) is introduced, a real-time compatible signal decomposition algorithm for separating electric brain activity and stimulation signal artifacts related to amplitude-modulated transcranial alternating current stimulation (AM-tACS) Employing SASS, phase and amplitude of single-trial steady state visual evoked potentials (SSVEPs) were reliably recovered from electroencephalography (EEG) recordings at the frequency targeted with AM-tACS SASS enables assessment of single-trial oscillatory brain activity at the target frequency during stimulation and paves the way for online adaptation of stimulation parameters to ongoing brain oscillations
Brain oscillations, e.g. measured by electro- or magnetoencephalography (EEG/MEG), are causally linked to brain functions that are fundamental for perception, cognition and learning. Recent advances in neurotechnology provide means to non-invasively target these oscillations using frequency-tuned amplitude-modulated transcranial alternating current stimulation (AM-tACS). However, online adaptation of stimulation parameters to ongoing brain oscillations remains an unsolved problem due to stimulation artifacts that impede such adaptation, particularly at the target frequency. Here, we introduce a real-time compatible artifact rejection algorithm (Stimulation Artifact Source Separation, SASS) that overcomes this limitation. SASS is a spatial filter (linear projection) removing EEG signal components that are maximally different in the presence versus absence of stimulation. This enables the reliable removal of stimulation-specific signal components, while leaving physiological signal components unaffected. For validation of SASS, we evoked brain activity with known phase and amplitude using 10 Hz visual flickers across 7 healthy human volunteers. 64-channel EEG was recorded during and in absence of 10 Hz AM-tACS targeting the visual cortex. Phase differences between AM-tACS and the visual stimuli were randomized, so that steady-state visually evoked potentials (SSVEPs) were phase-locked to the visual stimuli but not to the AM-tACS signal. For validation, distributions of single-trial amplitude and phase of EEG signals recorded during and in absence of AM-tACS were compared for each participant. When no artifact rejection method was applied, AM-tACS stimulation artifacts impeded assessment of single-trial SSVEP amplitude and phase. Using SASS, amplitude and phase of single trials recorded during and in absence of AM-tACS were comparable. These results indicate that SASS can be used to establish adaptive (closed-loop) AM-tACS, a potentially powerful tool to target various brain functions, and to investigate how AM-tACS interacts with electric brain oscillations.
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Affiliation(s)
- David Haslacher
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - University Medicine Berlin, Berlin, Germany
| | - Khaled Nasr
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - University Medicine Berlin, Berlin, Germany
| | - Stephen E Robinson
- National Institute of Mental Health (NIMH), MEG Core Facility, Bethesda, USA
| | - Christoph Braun
- MEG Center, University of Tübingen, Germany; CIMeC, Center of Mind/Brain Sciences, University of Trento, Italy
| | - Surjo R Soekadar
- Clinical Neurotechnology Lab, Neuroscience Research Center (NWFZ), Department of Psychiatry and Psychotherapy, Charité - University Medicine Berlin, Berlin, Germany; Applied Neurotechnology Lab, Department of Psychiatry and Psychotherapy, University Hospital of Tübingen, Germany.
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11
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van der Plas M, Wang D, Brittain JS, Hanslmayr S. Investigating the role of phase-synchrony during encoding of episodic memories using electrical stimulation. Cortex 2020; 133:37-47. [PMID: 33099074 DOI: 10.1016/j.cortex.2020.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/03/2020] [Accepted: 09/15/2020] [Indexed: 01/15/2023]
Abstract
The multi-sensory nature of episodic memories indicates that communication between a multitude of brain areas is required for their effective creation and recollection. Previous studies have suggested that the effectiveness of memory processes depends on theta synchronization (4 Hz) of sensory areas relevant to the memory. This study aimed to manipulate theta synchronization between different sensory areas in order to further test this hypothesis. We intend to entrain visual cortex with 4 Hz alternating current stimulation (tACS), while simultaneously entraining auditory cortex with 4 Hz amplitude-modulated sounds. By entraining these different sensory areas, which pertain to learned audio-visual memory associations, we expect to find that when theta is synchronized across the different sensory areas, the memory performance would be enhanced compared to when theta is not synchronized across the sensory areas. We found no evidence for such an effect in this study. It is unclear whether this is due to an inability of 4 Hz tACS to entrain the visual cortex reliably, or whether sensory entrainment is not the underlying mechanism required for episodic memory.
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Affiliation(s)
- Mircea van der Plas
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, United Kingdom
| | - Danying Wang
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, United Kingdom
| | - John-Stuart Brittain
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Simon Hanslmayr
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, United Kingdom.
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12
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Gao Y, Cavuoto L, Schwaitzberg S, Norfleet JE, Intes X, De S. The Effects of Transcranial Electrical Stimulation on Human Motor Functions: A Comprehensive Review of Functional Neuroimaging Studies. Front Neurosci 2020; 14:744. [PMID: 32792898 PMCID: PMC7393222 DOI: 10.3389/fnins.2020.00744] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 06/24/2020] [Indexed: 01/05/2023] Open
Abstract
Transcranial electrical stimulation (tES) is a promising tool to enhance human motor skills. However, the underlying physiological mechanisms are not fully understood. On the other hand, neuroimaging modalities provide powerful tools to map some of the neurophysiological biomarkers associated with tES. Here, a comprehensive review was undertaken to summarize the neuroimaging evidence of how tES affects human motor skills. A literature search has been done on the PubMed database, and 46 relative articles were selected. After reviewing these articles, we conclude that neuroimaging techniques are feasible to be coupled with tES and offer valuable information of cortical excitability, connectivity, and oscillations regarding the effects of tES on human motor behavior. The biomarkers derived from neuroimaging could also indicate the motor performance under tES conditions. This approach could advance the understanding of tES effects on motor skill and shed light on a new generation of adaptive stimulation models.
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Affiliation(s)
- Yuanyuan Gao
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Lora Cavuoto
- Department of Industrial and Systems Engineering, University at Buffalo, Buffalo, NY, United States
| | | | - Jack E. Norfleet
- U.S. Army Combat Capabilities Development Command, Soldier Center (CCDC SC), Orlando, FL, United States
- SFC Paul Ray Smith Simulation & Training Technology Center (STTC), Orlando, FL, United States
- Medical Simulation Research Branch (MSRB), Orlando, FL, United States
| | - Xavier Intes
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Suvranu De
- Center for Modeling, Simulation and Imaging in Medicine, Rensselaer Polytechnic Institute, Troy, NY, United States
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY, United States
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13
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Micera S, Caleo M, Chisari C, Hummel FC, Pedrocchi A. Advanced Neurotechnologies for the Restoration of Motor Function. Neuron 2020; 105:604-620. [PMID: 32078796 DOI: 10.1016/j.neuron.2020.01.039] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 11/15/2019] [Accepted: 01/27/2020] [Indexed: 01/23/2023]
Abstract
Stroke is one of the leading causes of long-term disability. Advanced technological solutions ("neurotechnologies") exploiting robotic systems and electrodes that stimulate the nervous system can increase the efficacy of stroke rehabilitation. Recent studies on these approaches have shown promising results. However, a paradigm shift in the development of new approaches must be made to significantly improve the clinical outcomes of neurotechnologies compared with those of traditional therapies. An "evolutionary" change can occur only by understanding in great detail the basic mechanisms of natural stroke recovery and technology-assisted neurorehabilitation. In this review, we first describe the results achieved by existing neurotechnologies and highlight their current limitations. In parallel, we summarize the data available on the mechanisms of recovery from electrophysiological, behavioral, and anatomical studies in humans and rodent models. Finally, we propose new approaches for the effective use of neurotechnologies in stroke survivors, as well as in people with other neurological disorders.
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Affiliation(s)
- Silvestro Micera
- The Biorobotics Institute and Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa, Italy; Bertarelli Foundation Chair in Translational Neuroengineering, Centre for Neuroprosthetics and Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Matteo Caleo
- Department of Biomedical Sciences, University of Padova, Padova, Italy; Institute of Neuroscience, National Research Council (CNR), Pisa, Italy
| | - Carmelo Chisari
- Neurorehabilitation Section, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Friedhelm C Hummel
- Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), École Polytechnique Fédérale de Lausanne (EPFL), 1202 Geneva, Switzerland; Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), École Polytechnique Fédérale de Lausanne (EPFL Valais), Clinique Romande de Réadaptation, 1951 Sion, Switzerland; Clinical Neuroscience, University of Geneva Medical School, 1202 Geneva, Switzerland
| | - Alessandra Pedrocchi
- Neuroengineering and Medical Robotics Laboratory NearLab, Department of Electronics, Information and Bioengineering, Politecnico di Milano, 20133 Milan, Italy
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14
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Bao SC, Khan A, Song R, Kai-yu Tong R. Rewiring the Lesioned Brain: Electrical Stimulation for Post-Stroke Motor Restoration. J Stroke 2020; 22:47-63. [PMID: 32027791 PMCID: PMC7005350 DOI: 10.5853/jos.2019.03027] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/03/2020] [Accepted: 01/06/2020] [Indexed: 02/06/2023] Open
Abstract
Electrical stimulation has been extensively applied in post-stroke motor restoration, but its treatment mechanisms are not fully understood. Stimulation of neuromotor control system at multiple levels manipulates the corresponding neuronal circuits and results in neuroplasticity changes of stroke survivors. This rewires the lesioned brain and advances functional improvement. This review addresses the therapeutic mechanisms of different stimulation modalities, such as noninvasive brain stimulation, peripheral electrical stimulation, and other emerging techniques. The existing applications, the latest progress, and future directions are discussed. The use of electrical stimulation to facilitate post-stroke motor recovery presents great opportunities in terms of targeted intervention and easy applicability. Further technical improvements and clinical studies are required to reveal the neuromodulatory mechanisms and to enhance rehabilitation therapy efficiency in stroke survivors and people with other movement disorders.
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Affiliation(s)
- Shi-chun Bao
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Ahsan Khan
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong, China
| | - Rong Song
- School of Biomedical Engineering, Sun Yat-Sen University, Guangzhou, China
| | - Raymond Kai-yu Tong
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Hong Kong, China
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15
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Recovering Brain Dynamics During Concurrent tACS-M/EEG: An Overview of Analysis Approaches and Their Methodological and Interpretational Pitfalls. Brain Topogr 2019; 32:1013-1019. [DOI: 10.1007/s10548-019-00727-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 08/20/2019] [Indexed: 12/27/2022]
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16
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McDermott TJ, Wiesman AI, Mills MS, Spooner RK, Coolidge NM, Proskovec AL, Heinrichs‐Graham E, Wilson TW. tDCS modulates behavioral performance and the neural oscillatory dynamics serving visual selective attention. Hum Brain Mapp 2019; 40:729-740. [PMID: 30368974 PMCID: PMC6328324 DOI: 10.1002/hbm.24405] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 09/10/2018] [Accepted: 09/10/2018] [Indexed: 12/24/2022] Open
Abstract
Transcranial direct-current stimulation (tDCS) is a noninvasive method for modulating human brain activity. Although there are several hypotheses about the net effects of tDCS on brain function, the field's understanding remains incomplete and this is especially true for neural oscillatory activity during cognitive task performance. In this study, we examined whether different polarities of occipital tDCS differentially alter flanker task performance and the underlying neural dynamics. To this end, 48 healthy adults underwent 20 min of anodal, cathodal, or sham occipital tDCS, and then completed a visual flanker task during high-density magnetoencephalography (MEG). The resulting oscillatory responses were imaged in the time-frequency domain using beamforming, and the effects of tDCS on task-related oscillations and spontaneous neural activity were assessed. The results indicated that anodal tDCS of the occipital cortices inhibited flanker task performance as measured by reaction time, elevated spontaneous activity in the theta (4-7 Hz) and alpha (9-14 Hz) bands in prefrontal and occipital cortices, respectively, and reduced task-related theta oscillatory activity in prefrontal cortices during task performance. Cathodal tDCS of the occipital cortices did not significantly affect behavior or any of these neuronal parameters in any brain region. Lastly, the power of theta oscillations in the prefrontal cortices was inversely correlated with reaction time. In conclusion, anodal tDCS modulated task-related oscillations and spontaneous activity across multiple cortical areas, both near the electrode and in distant sites that were putatively connected to the targeted regions.
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Affiliation(s)
- Timothy J. McDermott
- Center for MagnetoencephalographyUniversity of Nebraska Medical Center (UNMC)OmahaNebraska
| | - Alex I. Wiesman
- Center for MagnetoencephalographyUniversity of Nebraska Medical Center (UNMC)OmahaNebraska
- Department of Neurological SciencesUNMCOmahaNebraska
| | - Mackenzie S. Mills
- Center for MagnetoencephalographyUniversity of Nebraska Medical Center (UNMC)OmahaNebraska
| | - Rachel K. Spooner
- Center for MagnetoencephalographyUniversity of Nebraska Medical Center (UNMC)OmahaNebraska
- Department of Neurological SciencesUNMCOmahaNebraska
| | - Nathan M. Coolidge
- Center for MagnetoencephalographyUniversity of Nebraska Medical Center (UNMC)OmahaNebraska
- Department of PsychologyUniversity of NebraskaOmahaNebraska
| | - Amy L. Proskovec
- Center for MagnetoencephalographyUniversity of Nebraska Medical Center (UNMC)OmahaNebraska
- Department of PsychologyUniversity of NebraskaOmahaNebraska
| | - Elizabeth Heinrichs‐Graham
- Center for MagnetoencephalographyUniversity of Nebraska Medical Center (UNMC)OmahaNebraska
- Department of Neurological SciencesUNMCOmahaNebraska
| | - Tony W. Wilson
- Center for MagnetoencephalographyUniversity of Nebraska Medical Center (UNMC)OmahaNebraska
- Department of Neurological SciencesUNMCOmahaNebraska
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17
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Haberbosch L, Schmidt S, Jooss A, Köhn A, Kozarzewski L, Rönnefarth M, Scholz M, Brandt SA. Rebound or Entrainment? The Influence of Alternating Current Stimulation on Individual Alpha. Front Hum Neurosci 2019; 13:43. [PMID: 30809139 PMCID: PMC6380175 DOI: 10.3389/fnhum.2019.00043] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 01/25/2019] [Indexed: 01/11/2023] Open
Abstract
Alternating current stimulation (ACS) is an established means to manipulate intrinsic cortical oscillations. While working towards clinical impact, ACS mechanisms of action remain unclear. For ACS’s well-documented influence on occipital alpha, hypotheses include neuronal entrainment as well as rebound phenomena. As a retinal origin is also discussed, we employed a novel form of ACS with the advantage that it specifically targets occipital alpha-oscillations via retinofugal pathways retinofugal ACS (rACS). We aimed to confirm alpha-enhancement outlasting the duration of stimulation with 10 Hz rACS. To distinguish entrainment from rebound effects, we investigated the correlation between alpha peak frequency change and alpha-enhancement strength. We quantified the alpha band power before and after 10 Hz rACS in 15 healthy subjects. Alpha power enhancement and alpha peak frequency change were assessed over the occipital electrodes and compared to sham stimulation. RACS significantly enhanced occipital alpha power in comparison to sham stimulation (p < 0.05). Alpha peak frequency changed by a mean 0.02 Hz (± 0.04). A greater change in alpha peak frequency did not correlate with greater effects on alpha power. Our findings show an alpha-enhancement consistent with studies conducted for transcranial ACS (tACS) and contribute evidence for a retinal involvement in tACS effects on occipital alpha. Furthermore, the lack of correlation between alpha peak frequency change and alpha-enhancement strength provides an argument against entrainment effects and in favor of a rebound phenomenon.
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Affiliation(s)
- Linus Haberbosch
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Sein Schmidt
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Andreas Jooss
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Arvid Köhn
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Leonard Kozarzewski
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Maria Rönnefarth
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Scholz
- Neural Information Processing Group, University of Technology Berlin, Berlin, Germany
| | - Stephan A Brandt
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
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18
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Bao SC, Wong WW, Leung TWH, Tong KY. Cortico-Muscular Coherence Modulated by High-Definition Transcranial Direct Current Stimulation in People With Chronic Stroke. IEEE Trans Neural Syst Rehabil Eng 2018; 27:304-313. [PMID: 30596581 DOI: 10.1109/tnsre.2018.2890001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
High-definition transcranial direct current stimulation (HD-tDCS) is a potential neuromodulation apparatus for stroke rehabilitation. However, its modulatory effects in stroke subjects is still not well understood. In this paper, the offline modulatory effects of HD-tDCS on the ipsilesional primary motor cortex were investigated by performing wrist isometric contraction tasks before and after HD-tDCS in eleven unilateral chronic stroke subjects using a synchronized HD-tDCS and electroencephalogram/electromyography measurement system. This paper is a randomized, single blinded, and sham-controlled crossover study. Each subject randomly received three HD-tDCS (anode, cathode, and sham) with at least one-week washout period. Online feedback-guided medium-level wrist isometric contraction tasks were conducted for the affected upper limbs before stimulation and 10, 30, and 50 min after the end of 10-min 1-mA HD-tDCS. The characteristics of corticomuscular coherence (CMC), cortical oscillation power spectral density, and power spectral entropy were analyzed during tasks and compared across all sessions and stimulation conditions. Anode HD-tDCS induced significant CMC changes in stroke subjects, while cathode and sham stimulation did not induce significant CMC changes. The largest neuromodulation effects were observed at 10 min immediately after anodal HD-tDCS.
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19
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Herring JD, Esterer S, Marshall TR, Jensen O, Bergmann TO. Low-frequency alternating current stimulation rhythmically suppresses gamma-band oscillations and impairs perceptual performance. Neuroimage 2018; 184:440-449. [PMID: 30243972 DOI: 10.1016/j.neuroimage.2018.09.047] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/11/2018] [Accepted: 09/18/2018] [Indexed: 10/28/2022] Open
Abstract
Low frequency oscillations such as alpha (8-12 Hz) are hypothesized to rhythmically gate sensory processing, reflected by 40-100 Hz gamma band activity, via the mechanism of pulsed inhibition. We applied transcranial alternating current stimulation (TACS) at individual alpha frequency (IAF) and flanking frequencies (IAF-4 Hz, IAF+4 Hz) to the occipital cortex of healthy human volunteers during concurrent magnetoencephalography (MEG), while participants performed a visual detection task inducing strong gamma-band responses. Occipital (but not retinal) TACS phasically suppressed stimulus-induced gamma oscillations in the visual cortex and impaired target detection, with stronger phase-to-amplitude coupling predicting behavioral impairments. Retinal control TACS ruled out retino-thalamo-cortical entrainment resulting from (subthreshold) retinal stimulation. All TACS frequencies tested were effective, suggesting that visual gamma-band responses can be modulated by a range of low frequency oscillations. We propose that TACS-induced membrane potential modulations mimic the rhythmic change in cortical excitability by which spontaneous low frequency oscillations may eventually exert their impact when gating sensory processing via pulsed inhibition.
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Affiliation(s)
- Jim D Herring
- Donders Institute, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Sophie Esterer
- CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom; Donders Institute, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Tom R Marshall
- Department of Experimental Psychology, University of Oxford, United Kingdom; Donders Institute, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Ole Jensen
- School of Psychology, University of Birmingham, Birmingham, United Kingdom; Donders Institute, Radboud University Nijmegen, Nijmegen, the Netherlands
| | - Til O Bergmann
- Department of Neurology and Stroke, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany; Donders Institute, Radboud University Nijmegen, Nijmegen, the Netherlands.
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20
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Facilitated Event-Related Power Modulations during Transcranial Alternating Current Stimulation (tACS) Revealed by Concurrent tACS-MEG. eNeuro 2018; 5:eN-TNWR-0069-18. [PMID: 30073188 PMCID: PMC6070188 DOI: 10.1523/eneuro.0069-18.2018] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 06/01/2018] [Accepted: 06/07/2018] [Indexed: 01/02/2023] Open
Abstract
Non-invasive approaches to modulate oscillatory activity in the brain are increasingly popular in the scientific community. Transcranial alternating current stimulation (tACS) has been shown to modulate neural oscillations in a frequency-specific manner. However, due to a massive stimulation artifact at the targeted frequency, little is known about effects of tACS during stimulation. It remains unclear how the continuous application of tACS affects event-related oscillations during cognitive tasks. Depending on whether tACS influences pre- or post-stimulus oscillations, or both, the endogenous, event-related oscillatory dynamics could be pushed in various directions or not at all. A better understanding of these effects is crucial to plan, predict, and understand outcomes of solely behavioral tACS experiments. In the present study, a recently proposed procedure to suppress tACS artifacts by projecting MEG data into source-space using spatial filtering was utilized to recover event-related power modulations in the alpha-band during a mental rotation task. MEG data of 25 human subjects was continuously recorded. After 10-minute baseline measurement, participants received either 20 minutes of tACS at their individual alpha frequency or sham stimulation. Another 40 minutes of MEG data were acquired thereafter. Data were projected into source-space and carefully examined for residual artifacts. Results revealed strong facilitation of event-related power modulations in the alpha-band during tACS application. These results provide first direct evidence that tACS does not counteract top-down suppression of intrinsic oscillations, but rather enhances pre-existent power modulations within the range of the individual alpha (= stimulation) frequency.
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21
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tACS-mediated modulation of the auditory steady-state response as seen with MEG. Hear Res 2018; 364:90-95. [DOI: 10.1016/j.heares.2018.03.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/11/2018] [Accepted: 03/23/2018] [Indexed: 11/20/2022]
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22
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Vosskuhl J, Strüber D, Herrmann CS. Non-invasive Brain Stimulation: A Paradigm Shift in Understanding Brain Oscillations. Front Hum Neurosci 2018; 12:211. [PMID: 29887799 PMCID: PMC5980979 DOI: 10.3389/fnhum.2018.00211] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/07/2018] [Indexed: 11/13/2022] Open
Abstract
Cognitive neuroscience set out to understand the neural mechanisms underlying cognition. One central question is how oscillatory brain activity relates to cognitive processes. Up to now, most of the evidence supporting this relationship was correlative in nature. This situation changed dramatically with the recent development of non-invasive brain stimulation (NIBS) techniques, which open up new vistas for neuroscience by allowing researchers for the first time to validate their correlational theories by manipulating brain functioning directly. In this review, we focus on transcranial alternating current stimulation (tACS), an electrical brain stimulation method that applies sinusoidal currents to the intact scalp of human individuals to directly interfere with ongoing brain oscillations. We outline how tACS can impact human brain oscillations by employing different levels of observation from non-invasive tACS application in healthy volunteers and intracranial recordings in patients to animal studies demonstrating the effectiveness of alternating electric fields on neurons in vitro and in vivo. These findings likely translate to humans as comparable effects can be observed in human and animal studies. Neural entrainment and plasticity are suggested to mediate the behavioral effects of tACS. Furthermore, we focus on mechanistic theories about the relationship between certain cognitive functions and specific parameters of brain oscillaitons such as its amplitude, frequency, phase and phase coherence. For each of these parameters we present the current state of testing its functional relevance by means of tACS. Recent developments in the field of tACS are outlined which include the stimulation with physiologically inspired non-sinusoidal waveforms, stimulation protocols which allow for the observation of online-effects, and closed loop applications of tACS.
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Affiliation(s)
- Johannes Vosskuhl
- Experimental Psychology Lab, Center for Excellence “Hearing4all,” European Medical School, University of Oldenburg, Oldenburg, Germany
| | - Daniel Strüber
- Experimental Psychology Lab, Center for Excellence “Hearing4all,” European Medical School, University of Oldenburg, Oldenburg, Germany
- Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
| | - Christoph S. Herrmann
- Experimental Psychology Lab, Center for Excellence “Hearing4all,” European Medical School, University of Oldenburg, Oldenburg, Germany
- Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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23
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Fuscà M, Ruhnau P, Neuling T, Weisz N. Local Network-Level Integration Mediates Effects of Transcranial Alternating Current Stimulation. Brain Connect 2018; 8:212-219. [DOI: 10.1089/brain.2017.0564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Marco Fuscà
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
| | - Philipp Ruhnau
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany
| | - Toralf Neuling
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
- Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Nathan Weisz
- Center for Mind/Brain Sciences, University of Trento, Trento, Italy
- Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
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24
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Wilson TW, McDermott TJ, Mills MS, Coolidge NM, Heinrichs-Graham E. tDCS Modulates Visual Gamma Oscillations and Basal Alpha Activity in Occipital Cortices: Evidence from MEG. Cereb Cortex 2018; 28:1597-1609. [PMID: 28334214 PMCID: PMC5907344 DOI: 10.1093/cercor/bhx055] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 01/13/2017] [Accepted: 02/16/2017] [Indexed: 01/03/2023] Open
Abstract
Transcranial direct-current stimulation (tDCS) is now a widely used method for modulating the human brain, but the resulting physiological effects are not understood. Recent studies have combined magnetoencephalography (MEG) with simultaneous tDCS to evaluate online changes in occipital alpha and gamma oscillations, but no study to date has quantified the offline (i.e., after tDCS) alterations in these responses. Thirty-five healthy adults received active or sham anodal tDCS to the occipital cortices, and then completed a visual stimulation paradigm during MEG that is known to elicit robust gamma and alpha oscillations. The resulting MEG data were imaged and peak voxel time series were extracted to evaluate tDCS effects. We found that tDCS to the occipital increased the amplitude of local gamma oscillations, and basal alpha levels during the baseline. tDCS was also associated with network-level effects, including increased gamma oscillations in the prefrontal cortex, parietal, and other visual attention regions. Finally, although tDCS did not modulate peak gamma frequency, this variable was inversely correlated with gamma amplitude, which is consistent with a GABA-gamma link. In conclusion, tDCS alters gamma oscillations and basal alpha levels. The net offline effects on gamma activity are consistent with the view that anodal tDCS decreases local GABA.
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Affiliation(s)
- Tony W Wilson
- Department of Neurological Sciences, University of Nebraska Medical Center (UNMC), Omaha, NE, USA
- Department of Pharmacology and Experimental Neurosciences, UNMC, Omaha, NE, USA
- Center for Magnetoencephalography, UNMC, Omaha, NE 68198, USA
| | | | | | | | - Elizabeth Heinrichs-Graham
- Department of Neurological Sciences, University of Nebraska Medical Center (UNMC), Omaha, NE, USA
- Center for Magnetoencephalography, UNMC, Omaha, NE 68198, USA
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25
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Abstract
PURPOSE OF REVIEW An increase in oscillatory activity in the γ-frequency band (approximately 50-100 Hz) has long been noted during human movement. However, its functional role has been difficult to elucidate. The advent of novel techniques, particularly transcranial alternating current stimulation (tACS), has dramatically increased our ability to study γ oscillations. Here, we review our current understanding of the role of γ oscillations in the human motor cortex, with reference to γ activity outside the motor system, and evidence from animal models. RECENT FINDINGS Evidence for the neurophysiological basis of human γ oscillations is beginning to emerge. Multimodal studies, essential given the necessarily indirect measurements acquired in humans, are beginning to provide convergent evidence for the role of γ oscillations in movement, and their relationship to plasticity. SUMMARY Human motor cortical γ oscillations appear to play a key role in movement, and relate to learning. However, there are still major questions to be answered about their physiological basis and precise role in human plasticity. It is to be hoped that future research will take advantage of recent technical advances and the physiological basis and functional significance of this intriguing and important brain rhythm will be fully elucidated.
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Affiliation(s)
- Magdalena Nowak
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 9DU UK
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford, OX3 7JX UK
| | - Catharina Zich
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 9DU UK
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford, OX3 7JX UK
| | - Charlotte J. Stagg
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, OX3 9DU UK
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford, OX3 7JX UK
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26
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Mancini M, Pellicciari MC, Brignani D, Mauri P, De Marchis C, Miniussi C, Conforto S. Automatic artifact suppression in simultaneous tDCS-EEG using adaptive filtering. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2015:2729-32. [PMID: 26736856 DOI: 10.1109/embc.2015.7318956] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that can be used in cognitive and clinical protocols in order to modulate neural activity. Although some macro effects are known, the underlying mechanisms are still not clear. tDCS in combination with electroencephalography (EEG) could help to understand these mechanisms from a neural point of view. However, simultaneous tDCS-EEG still remains challenging because of the artifacts that affect the recorded signals. In this paper, an automated artifact cancellation method based on adaptive filtering is proposed. Using independent component analysis (ICA), the artifacts were characterized using data from both a phantom and a group of healthy subjects. The resulting filter can successfully remove tDCS-related artifacts during anodal and cathodal stimulations.
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27
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Transcranial electric stimulation (tES) and NeuroImaging: the state-of-the-art, new insights and prospects in basic and clinical neuroscience. Neuroimage 2018; 140:1-3. [PMID: 27633745 DOI: 10.1016/j.neuroimage.2016.08.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Transcranial electric stimulation (tES) of the brain has attracted an increased interest in recent years. Yet, despite remarkable research efforts to date, the underlying neurobiological mechanisms of tES' effects are still incompletely understood. This Special Issue aims to provide a comprehensive and up-to-date overview of the state-of-the-art in studies combining tES and neuroimaging, while introducing most recent insights and outlining future prospects related to this new and rapidly growing field. The findings reported here combine methodological advancements with insights into the underlying mechanisms of tES itself. At the same time, they also point to the many caveats and specific challenges associated with such studies, which can arise from both technical and biological sources. Besides promising to advance basic neuroscience, combined tES and neuroimaging studies may also substantially change previous conceptions about the methods of action of electric or magnetic stimulation on the brain.
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28
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Baxter BS, Edelman BJ, Sohrabpour A, He B. Anodal Transcranial Direct Current Stimulation Increases Bilateral Directed Brain Connectivity during Motor-Imagery Based Brain-Computer Interface Control. Front Neurosci 2017; 11:691. [PMID: 29270110 PMCID: PMC5725434 DOI: 10.3389/fnins.2017.00691] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 11/23/2017] [Indexed: 01/29/2023] Open
Abstract
Transcranial direct current stimulation (tDCS) has been shown to affect motor and cognitive task performance and learning when applied to brain areas involved in the task. Targeted stimulation has also been found to alter connectivity within the stimulated hemisphere during rest. However, the connectivity effect of the interaction of endogenous task specific activity and targeted stimulation is unclear. This study examined the aftereffects of concurrent anodal high-definition tDCS over the left sensorimotor cortex with motor network connectivity during a one-dimensional EEG based sensorimotor rhythm brain-computer interface (SMR-BCI) task. Directed connectivity following anodal tDCS illustrates altered connections bilaterally between frontal and parietal regions, and these alterations occur in a task specific manner; connections between similar cortical regions are altered differentially during left and right imagination trials. During right-hand imagination following anodal tDCS, there was an increase in outflow from the left premotor cortex (PMC) to multiple regions bilaterally in the motor network and increased inflow to the stimulated sensorimotor cortex from the ipsilateral PMC and contralateral sensorimotor cortex. During left-hand imagination following anodal tDCS, there was increased outflow from the stimulated sensorimotor cortex to regions across the motor network. Significant correlations between connectivity and the behavioral measures of total correct trials and time-to-hit (TTH) correct trials were also found, specifically that the input to the left PMC correlated with decreased right hand imagination performance and that flow from the ipsilateral posterior parietal cortex (PPC) to midline sensorimotor cortex correlated with improved performance for both right and left hand imagination. These results indicate that tDCS interacts with task-specific endogenous activity to alter directed connectivity during SMR-BCI. In order to predict and maximize the targeted effect of tDCS, the interaction of stimulation with the dynamics of endogenous activity needs to be examined comprehensively and understood.
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Affiliation(s)
- Bryan S. Baxter
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Bradley J. Edelman
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Abbas Sohrabpour
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Bin He
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
- Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN, United States
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29
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Noury N, Siegel M. Analyzing EEG and MEG signals recorded during tES, a reply. Neuroimage 2017; 167:53-61. [PMID: 29155079 DOI: 10.1016/j.neuroimage.2017.11.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/20/2017] [Accepted: 11/12/2017] [Indexed: 10/18/2022] Open
Abstract
Transcranial Electric Stimulation (tES) is a widely used non-invasive brain stimulation technique. However, strong stimulation artifacts complicate the investigation of neural activity with EEG or MEG during tES. Thus, studying brain signals during tES requires detailed knowledge about the properties of these artifacts. Recently, we characterized the phase- and amplitude-relationship between tES stimulation currents and tES artifacts in EEG and MEG and provided a mathematical model of these artifacts (Noury and Siegel, 2017, and Noury et al., 2016, respectively). Among several other features, we showed that, independent of the stimulation current, the amplitude of tES artifacts is modulated time locked to heartbeat and respiration. In response to our work, a recent paper (Neuling et al., 2017) raised several points concerning the employed stimulation device and methodology. Here, we discuss these points, explain potential misunderstandings, and show that none of the raised concerns are applicable to our results. Furthermore, we explain in detail the physics underlying tES artifacts, and discuss several approaches how to study brain function during tES in the presence of residual artifacts.
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Affiliation(s)
- Nima Noury
- Centre for Integrative Neuroscience & MEG Center, University of Tübingen, Germany; IMPRS for Cognitive and Systems Neuroscience, Tübingen, Germany.
| | - Markus Siegel
- Centre for Integrative Neuroscience & MEG Center, University of Tübingen, Germany.
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30
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Krause MR, Zanos TP, Csorba BA, Pilly PK, Choe J, Phillips ME, Datta A, Pack CC. Transcranial Direct Current Stimulation Facilitates Associative Learning and Alters Functional Connectivity in the Primate Brain. Curr Biol 2017; 27:3086-3096.e3. [PMID: 29033331 DOI: 10.1016/j.cub.2017.09.020] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 07/19/2017] [Accepted: 09/11/2017] [Indexed: 01/12/2023]
Abstract
There has been growing interest in transcranial direct current stimulation (tDCS), a non-invasive technique purported to modulate neural activity via weak, externally applied electric fields. Although some promising preliminary data have been reported for applications ranging from stroke rehabilitation to cognitive enhancement, little is known about how tDCS affects the human brain, and some studies have concluded that it may have no effect at all. Here, we describe a macaque model of tDCS that allows us to simultaneously examine the effects of tDCS on brain activity and behavior. We find that applying tDCS to right prefrontal cortex improves monkeys' performance on an associative learning task. While firing rates do not change within the targeted area, tDCS does induce large low-frequency oscillations in the underlying tissue. These oscillations alter functional connectivity, both locally and between distant brain areas, and these long-range changes correlate with tDCS's effects on behavior. Together, these results are consistent with the idea that tDCS leads to widespread changes in brain activity and suggest that it may be a valuable method for cheaply and non-invasively altering functional connectivity in humans.
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Affiliation(s)
- Matthew R Krause
- Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | | | - Bennett A Csorba
- Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada
| | - Praveen K Pilly
- Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA 90265, USA.
| | - Jaehoon Choe
- Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA 90265, USA
| | - Matthew E Phillips
- Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA 90265, USA
| | | | - Christopher C Pack
- Montreal Neurological Institute, McGill University, Montreal, QC H3A 2B4, Canada.
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31
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Noury N, Siegel M. Phase properties of transcranial electrical stimulation artifacts in electrophysiological recordings. Neuroimage 2017; 158:406-416. [DOI: 10.1016/j.neuroimage.2017.07.010] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 06/14/2017] [Accepted: 07/09/2017] [Indexed: 11/27/2022] Open
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32
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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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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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34
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Heinrichs-Graham E, McDermott TJ, Mills MS, Coolidge NM, Wilson TW. Transcranial direct-current stimulation modulates offline visual oscillatory activity: A magnetoencephalography study. Cortex 2016; 88:19-31. [PMID: 28042984 DOI: 10.1016/j.cortex.2016.11.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/10/2016] [Accepted: 11/28/2016] [Indexed: 11/16/2022]
Abstract
Transcranial direct-current stimulation (tDCS) is a noninvasive neuromodulatory method that involves delivering low amplitude, direct current to specific regions of the brain. While a wealth of literature shows changes in behavior and cognition following tDCS administration, the underlying neuronal mechanisms remain largely unknown. Neuroimaging studies have generally used fMRI and shown only limited consensus to date, while the few electrophysiological studies have reported mostly null or counterintuitive findings. The goal of the current investigation was to quantify tDCS-induced alterations in the oscillatory dynamics of visual processing. To this end, we performed either active or sham tDCS using an occipital-frontal electrode configuration, and then recorded magnetoencephalography (MEG) offline during a visual entrainment task. Significant oscillatory responses were imaged in the time-frequency domain using beamforming, and the effects of tDCS on absolute and relative power were assessed. The results indicated significantly increased basal alpha levels in the occipital cortex following anodal tDCS, as well as reduced occipital synchronization at the second harmonic of the stimulus-flicker frequency relative to sham stimulation. In addition, we found reduced power in brain regions near the cathode (e.g., right inferior frontal gyrus [IFG]) following active tDCS, which was absent in the sham group. Taken together, these results suggest that anodal tDCS of the occipital cortices differentially modulates spontaneous and induced activity, and may interfere with the entrainment of neuronal populations by a visual-flicker stimulus. These findings also demonstrate the importance of electrode configuration on whole-brain dynamics, and highlight the deceptively complicated nature of tDCS in the context of neurophysiology.
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Affiliation(s)
- Elizabeth Heinrichs-Graham
- Department of Neurological Sciences, University of Nebraska Medical Center (UNMC), Omaha, NE, USA; Center for Magnetoencephalography, UNMC, Omaha, NE, USA; Department of Pharmacology and Experimental Neuroscience, UNMC, Omaha, NE, USA
| | | | | | | | - Tony W Wilson
- Department of Neurological Sciences, University of Nebraska Medical Center (UNMC), Omaha, NE, USA; Center for Magnetoencephalography, UNMC, Omaha, NE, USA; Department of Pharmacology and Experimental Neuroscience, UNMC, Omaha, NE, USA.
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35
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Baxter BS, Edelman BJ, Nesbitt N, He B. Sensorimotor Rhythm BCI with Simultaneous High Definition-Transcranial Direct Current Stimulation Alters Task Performance. Brain Stimul 2016; 9:834-841. [PMID: 27522166 PMCID: PMC5143161 DOI: 10.1016/j.brs.2016.07.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/10/2016] [Accepted: 07/12/2016] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Transcranial direct current stimulation (tDCS) has been used to alter the excitability of neurons within the cerebral cortex. Improvements in motor learning have been found in multiple studies when tDCS was applied to the motor cortex before or during task learning. The motor cortex is also active during the performance of motor imagination, a cognitive task during which a person imagines, but does not execute, a movement. Motor imagery can be used with noninvasive brain computer interfaces (BCIs) to control virtual objects in up to three dimensions, but to master control of such devices requires long training times. OBJECTIVE To evaluate the effect of high-definition tDCS on the performance and underlying electrophysiology of motor imagery based BCI. METHODS We utilize high-definition tDCS to investigate the effect of stimulation on motor imagery-based BCI performance across and within sessions over multiple training days. RESULTS We report a decreased time-to-hit with anodal stimulation both within and across sessions. We also found differing electrophysiological changes of the stimulated sensorimotor cortex during online BCI task performance for left vs. right trials. Cathodal stimulation led to a decrease in alpha and beta band power during task performance compared to sham stimulation for right hand imagination trials. CONCLUSION These results suggest that unilateral tDCS over the sensorimotor motor cortex differentially affects cortical areas based on task specific neural activation.
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Affiliation(s)
- Bryan S Baxter
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Bradley J Edelman
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Nicholas Nesbitt
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Bin He
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA; Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN, USA.
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36
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Yanagisawa T, Fukuma R, Seymour B, Hosomi K, Kishima H, Shimizu T, Yokoi H, Hirata M, Yoshimine T, Kamitani Y, Saitoh Y. Induced sensorimotor brain plasticity controls pain in phantom limb patients. Nat Commun 2016; 7:13209. [PMID: 27807349 PMCID: PMC5095287 DOI: 10.1038/ncomms13209] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 09/12/2016] [Indexed: 12/02/2022] Open
Abstract
The cause of pain in a phantom limb after partial or complete deafferentation is an important problem. A popular but increasingly controversial theory is that it results from maladaptive reorganization of the sensorimotor cortex, suggesting that experimental induction of further reorganization should affect the pain, especially if it results in functional restoration. Here we use a brain–machine interface (BMI) based on real-time magnetoencephalography signals to reconstruct affected hand movements with a robotic hand. BMI training induces significant plasticity in the sensorimotor cortex, manifested as improved discriminability of movement information and enhanced prosthetic control. Contrary to our expectation that functional restoration would reduce pain, the BMI training with the phantom hand intensifies the pain. In contrast, BMI training designed to dissociate the prosthetic and phantom hands actually reduces pain. These results reveal a functional relevance between sensorimotor cortical plasticity and pain, and may provide a novel treatment with BMI neurofeedback. Pain in a phantom limb after limb deafferentation may be due to maladaptive sensorimotor representation. Here the authors find that sensorimotor plasticity induced by BMI training with the phantom hand, contrary to expectation, increased pain while dissociating prosthetic movements from the phantom arm relieved the pain.
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Affiliation(s)
- Takufumi Yanagisawa
- Department of Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Division of Functional Diagnostic Science, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Neuroinformatics, ATR Computational Neuroscience Laboratories, 2-2-2 Hikaridai, Seika-cho, Kyoto 619-0288, Japan.,Department of Neuroinformatics, CiNet Computational Neuroscience Laboratories, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,JST PRESTO, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Division of Clinical Neuroengineering, Osaka University, Global Center for Medical Engineering and Informactics, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Ryohei Fukuma
- Department of Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Neuroinformatics, ATR Computational Neuroscience Laboratories, 2-2-2 Hikaridai, Seika-cho, Kyoto 619-0288, Japan.,Department of Neuroinformatics, CiNet Computational Neuroscience Laboratories, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Graduate School of Information Science, Nara Institute of Science and Technology, 8916-5 Takayamacho, Ikoma, Nara 630-0192, Japan
| | - Ben Seymour
- Department of Engineering, University of Cambridge, Computational and Biological Learning Laboratory, Trumpington Street, Cambridge CB2 1PZ, UK.,National Institute for Information and Communications Technology, Center for Information and Neural Networks, 1-3 Suita, Osaka 565-0871, Japan
| | - Koichi Hosomi
- Department of Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Neuromodulation and Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Haruhiko Kishima
- Department of Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takeshi Shimizu
- Department of Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Neuromodulation and Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hiroshi Yokoi
- Department of Mechanical Engineering and Intelligent Systems, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan
| | - Masayuki Hirata
- Department of Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Neuroinformatics, CiNet Computational Neuroscience Laboratories, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Division of Clinical Neuroengineering, Osaka University, Global Center for Medical Engineering and Informactics, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Toshiki Yoshimine
- Department of Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Neuroinformatics, CiNet Computational Neuroscience Laboratories, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Division of Clinical Neuroengineering, Osaka University, Global Center for Medical Engineering and Informactics, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yukiyasu Kamitani
- Department of Neuroinformatics, ATR Computational Neuroscience Laboratories, 2-2-2 Hikaridai, Seika-cho, Kyoto 619-0288, Japan.,Graduate School of Information Science, Nara Institute of Science and Technology, 8916-5 Takayamacho, Ikoma, Nara 630-0192, Japan.,Graduate School of Informatics, Kyoto University, Yoshidahonmachi, Sakyoku, Kyoto 606-8501, Japan
| | - Youichi Saitoh
- Department of Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.,Department of Neuromodulation and Neurosurgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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Effects of transcranial direct current stimulation on the functional coupling of the sensorimotor cortical network. Neuroimage 2016; 140:50-6. [DOI: 10.1016/j.neuroimage.2016.01.051] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 01/18/2016] [Accepted: 01/22/2016] [Indexed: 11/21/2022] Open
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Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives. Neuroimage 2016; 140:4-19. [DOI: 10.1016/j.neuroimage.2016.02.012] [Citation(s) in RCA: 197] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 01/26/2016] [Accepted: 02/07/2016] [Indexed: 12/23/2022] Open
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39
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Data-driven forward model inference for EEG brain imaging. Neuroimage 2016; 139:249-258. [DOI: 10.1016/j.neuroimage.2016.06.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 11/23/2022] Open
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40
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Physiological processes non-linearly affect electrophysiological recordings during transcranial electric stimulation. Neuroimage 2016; 140:99-109. [DOI: 10.1016/j.neuroimage.2016.03.065] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 03/23/2016] [Accepted: 03/24/2016] [Indexed: 11/18/2022] Open
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41
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Hanley CJ, Singh KD, McGonigle DJ. Transcranial modulation of brain oscillatory responses: A concurrent tDCS–MEG investigation. Neuroimage 2016; 140:20-32. [DOI: 10.1016/j.neuroimage.2015.12.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 12/13/2015] [Accepted: 12/14/2015] [Indexed: 10/22/2022] Open
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Romei V, Thut G, Silvanto J. Information-Based Approaches of Noninvasive Transcranial Brain Stimulation. Trends Neurosci 2016; 39:782-795. [PMID: 27697295 DOI: 10.1016/j.tins.2016.09.001] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 09/01/2016] [Accepted: 09/06/2016] [Indexed: 11/16/2022]
Abstract
Progress in cognitive neuroscience relies on methodological developments to increase the specificity of knowledge obtained regarding brain function. For example, in functional neuroimaging the current trend is to study the type of information carried by brain regions rather than simply compare activation levels induced by task manipulations. In this context noninvasive transcranial brain stimulation (NTBS) in the study of cognitive functions may appear coarse and old fashioned in its conventional uses. However, in their multitude of parameters, and by coupling them with behavioral manipulations, NTBS protocols can reach the specificity of imaging techniques. Here we review the different paradigms that have aimed to accomplish this in both basic science and clinical settings and follow the general philosophy of information-based approaches.
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Affiliation(s)
- Vincenzo Romei
- Centre for Brain Science, Department of Psychology, University of Essex, Colchester, UK.
| | - Gregor Thut
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK.
| | - Juha Silvanto
- Department of Psychology, Faculty of Science and Technology, University of Westminster, London, UK.
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Muldoon SF, Pasqualetti F, Gu S, Cieslak M, Grafton ST, Vettel JM, Bassett DS. Stimulation-Based Control of Dynamic Brain Networks. PLoS Comput Biol 2016; 12:e1005076. [PMID: 27611328 PMCID: PMC5017638 DOI: 10.1371/journal.pcbi.1005076] [Citation(s) in RCA: 154] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 07/23/2016] [Indexed: 11/30/2022] Open
Abstract
The ability to modulate brain states using targeted stimulation is increasingly being employed to treat neurological disorders and to enhance human performance. Despite the growing interest in brain stimulation as a form of neuromodulation, much remains unknown about the network-level impact of these focal perturbations. To study the system wide impact of regional stimulation, we employ a data-driven computational model of nonlinear brain dynamics to systematically explore the effects of targeted stimulation. Validating predictions from network control theory, we uncover the relationship between regional controllability and the focal versus global impact of stimulation, and we relate these findings to differences in the underlying network architecture. Finally, by mapping brain regions to cognitive systems, we observe that the default mode system imparts large global change despite being highly constrained by structural connectivity. This work forms an important step towards the development of personalized stimulation protocols for medical treatment or performance enhancement. Brain stimulation is increasingly used in clinical settings to treat neurological disorders, but much remains unknown about how stimulation to a single brain region impacts large-scale, brain network activity. Using structural neuroimaging scans, we create computational models of brain dynamics for eight participants to explore how structure-function relationships constrain the effect of stimulation to a single region on the brain as a whole. Our results show that network control theory can be used to predict if the effects of stimulation remain focal or spread globally, and structural connectivity differentially constrains the effects of regional stimulation. Additionally, we study how stimulation of different cognitive systems spreads throughout the brain and find that stimulation of regions within the default mode network provide a mechanism to impart large change in overall brain dynamics through a densely connected structural network. By revealing how the stimulation of different brain regions and cognitive systems spreads differently through the brain, we provide a modeling framework to develop stimulation protocols to personalize medical treatments, enable performance enhancements, and facilitate cortical plasticity.
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Affiliation(s)
- Sarah Feldt Muldoon
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- US Army Research Laboratory, Aberdeen Proving Ground, Maryland, United States of America
- Department of Mathematics and Computational and Data-Enabled Science and Engineering Program, University at Buffalo, SUNY, Buffalo, New York, United States of America
| | - Fabio Pasqualetti
- Department of Mechanical Engineering, University of California, Riverside, Riverside, California, United States of America
| | - Shi Gu
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Applied Mathematics and Computational Science Graduate Program, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Matthew Cieslak
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Scott T. Grafton
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Jean M. Vettel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- US Army Research Laboratory, Aberdeen Proving Ground, Maryland, United States of America
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Danielle S. Bassett
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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44
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Rejecting deep brain stimulation artefacts from MEG data using ICA and mutual information. J Neurosci Methods 2016; 268:131-41. [PMID: 27090949 DOI: 10.1016/j.jneumeth.2016.04.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 04/11/2016] [Accepted: 04/12/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND Recording brain activity during deep brain stimulation (DBS) using magnetoencephalography (MEG) can potentially help clarifying the neurophysiological mechanism of DBS. The DBS artefact, however, distorts MEG data significantly. We present an artefact rejection approach to remove the DBS artefact from MEG data. NEW METHODS We developed an approach consisting of four consecutive steps: (i) independent component analysis was used to decompose MEG data to independent components (ICs); (ii) mutual information (MI) between stimulation signal and all ICs was calculated; (iii) artefactual ICs were identified by means of an MI threshold; and (iv) the MEG signal was reconstructed using only non-artefactual ICs. This approach was applied to MEG data from five Parkinson's disease patients with implanted DBS stimulators. MEG was recorded with DBS ON (unilateral stimulation of the subthalamic nucleus) and DBS OFF during two experimental conditions: a visual attention task and alternating right and left median nerve stimulation. RESULTS With the presented approach most of the artefact could be removed. The signal of interest could be retrieved in both conditions. COMPARISON WITH EXISTING METHODS In contrast to existing artefact rejection methods for MEG-DBS data (tSSS and S(3)P), the proposed method uses the actual artefact source, i.e. the stimulation signal, as reference signal. CONCLUSIONS Using the presented method, the DBS artefact can be significantly rejected and the physiological data can be restored. This will facilitate research addressing the impact of DBS on brain activity during rest and various tasks.
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Chander BS, Witkowski M, Braun C, Robinson SE, Born J, Cohen LG, Birbaumer N, Soekadar SR. tACS Phase Locking of Frontal Midline Theta Oscillations Disrupts Working Memory Performance. Front Cell Neurosci 2016; 10:120. [PMID: 27199669 PMCID: PMC4858529 DOI: 10.3389/fncel.2016.00120] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 04/25/2016] [Indexed: 12/26/2022] Open
Abstract
Background: Frontal midline theta (FMT) oscillations (4–8 Hz) are strongly related to cognitive and executive control during mental tasks such as memory processing, arithmetic problem solving or sustained attention. While maintenance of temporal order information during a working memory (WM) task was recently linked to FMT phase, a positive correlation between FMT power, WM demand and WM performance was shown. However, the relationship between these measures is not well understood, and it is unknown whether purposeful FMT phase manipulation during a WM task impacts FMT power and WM performance. Here we present evidence that FMT phase manipulation mediated by transcranial alternating current stimulation (tACS) can block WM demand-related FMT power increase (FMTΔpower) and disrupt normal WM performance. Methods: Twenty healthy volunteers were assigned to one of two groups (group A, group B) and performed a 2-back task across a baseline block (block 1) and an intervention block (block 2) while 275-sensor magnetoencephalography (MEG) was recorded. After no stimulation was applied during block 1, participants in group A received tACS oscillating at their individual FMT frequency over the prefrontal cortex (PFC) while group B received sham stimulation during block 2. After assessing and mapping phase locking values (PLV) between the tACS signal and brain oscillatory activity across the whole brain, FMT power and WM performance were assessed and compared between blocks and groups. Results: During block 2 of group A but not B, FMT oscillations showed increased PLV across task-related cortical areas underneath the frontal tACS electrode. While WM task-related FMTΔpower and WM performance were comparable across groups in block 1, tACS resulted in lower FMTΔpower and WM performance compared to sham stimulation in block 2. Conclusion: tACS-related manipulation of FMT phase can disrupt WM performance and influence WM task-related FMTΔpower. This finding may have important implications for the treatment of brain disorders such as depression and attention deficit disorder associated with abnormal regulation of FMT activity or disorders characterized by dysfunctional coupling of brain activity, e.g., epilepsy, Alzheimer’s or Parkinson’s disease (AD/PD).
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Affiliation(s)
- Bankim S Chander
- Applied Neurotechnology Lab, Department of Psychiatry and Psychotherapy, University Hospital of Tübingen Tübingen, Germany
| | - Matthias Witkowski
- Applied Neurotechnology Lab, Department of Psychiatry and Psychotherapy, University Hospital of Tübingen Tübingen, Germany
| | - Christoph Braun
- MEG Center, University Hospital of TübingenTübingen, Germany; CIMeC, Center for Mind/Brain Sciences, University of TrentoTrento, Italy
| | - Stephen E Robinson
- National Institute of Mental Health (NIMH), MEG Core Facility Bethesda, MD, USA
| | - Jan Born
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen Tübingen, Germany
| | - Leonardo G Cohen
- National Institute of Neurological Disorders and Stroke (NINDS) Bethesda, MD, USA
| | - Niels Birbaumer
- Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen Tübingen, Germany
| | - Surjo R Soekadar
- Applied Neurotechnology Lab, Department of Psychiatry and Psychotherapy, University Hospital of TübingenTübingen, Germany; MEG Center, University Hospital of TübingenTübingen, Germany
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46
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Hämmerer D, Bonaiuto J, Klein-Flügge M, Bikson M, Bestmann S. Selective alteration of human value decisions with medial frontal tDCS is predicted by changes in attractor dynamics. Sci Rep 2016; 6:25160. [PMID: 27146700 PMCID: PMC4857193 DOI: 10.1038/srep25160] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 03/04/2016] [Indexed: 02/02/2023] Open
Abstract
During value-based decision making, ventromedial prefrontal cortex (vmPFC) is thought to support choices by tracking the expected gain from different outcomes via a competition-based process. Using a computational neurostimulation approach we asked how perturbing this region might alter this competition and resulting value decisions. We simulated a perturbation of neural dynamics in a biophysically informed model of decision-making through in silico depolarization at the level of neuronal ensembles. Simulated depolarization increased baseline firing rates of pyramidal neurons, which altered their susceptibility to background noise, and thereby increased choice stochasticity. These behavioural predictions were compared to choice behaviour in healthy participants performing similar value decisions during transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique. We placed the soma depolarizing electrode over medial frontal PFC. In line with model predictions, this intervention resulted in more random choices. By contrast, no such effect was observed when placing the depolarizing electrode over lateral PFC. Using a causal manipulation of ventromedial and lateral prefrontal function, these results provide support for competition-based choice dynamics in human vmPFC, and introduce computational neurostimulation as a mechanistic assay for neurostimulation studies of cognition.
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Affiliation(s)
- D. Hämmerer
- Institute of Cognitive Neuroscience, London, United Kingdom
- Lifespan Psychology, MPI for Human Development, Berlin, Germany
| | - J. Bonaiuto
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, London, United Kingdom
| | - M. Klein-Flügge
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, London, United Kingdom
- Department of Experimental Psychology, Oxford, United Kingdom
| | - M. Bikson
- Department for Biomedical Engineering, The City University of New York, New York, NY, USA
| | - S. Bestmann
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, University College London, London, United Kingdom
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Ruhnau P, Keitel C, Lithari C, Weisz N, Neuling T. Flicker-Driven Responses in Visual Cortex Change during Matched-Frequency Transcranial Alternating Current Stimulation. Front Hum Neurosci 2016; 10:184. [PMID: 27199707 PMCID: PMC4844646 DOI: 10.3389/fnhum.2016.00184] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 04/11/2016] [Indexed: 01/23/2023] Open
Abstract
We tested a novel combination of two neuro-stimulation techniques, transcranial alternating current stimulation (tACS) and frequency tagging, that promises powerful paradigms to study the causal role of rhythmic brain activity in perception and cognition. Participants viewed a stimulus flickering at 7 or 11 Hz that elicited periodic brain activity, termed steady-state responses (SSRs), at the same temporal frequency and its higher order harmonics. Further, they received simultaneous tACS at 7 or 11 Hz that either matched or differed from the flicker frequency. Sham tACS served as a control condition. Recent advances in reconstructing cortical sources of oscillatory activity allowed us to measure SSRs during concurrent tACS, which is known to impose strong artifacts in magnetoencephalographic (MEG) recordings. For the first time, we were thus able to demonstrate immediate effects of tACS on SSR-indexed early visual processing. Our data suggest that tACS effects are largely frequency-specific and reveal a characteristic pattern of differential influences on the harmonic constituents of SSRs.
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Affiliation(s)
- Philipp Ruhnau
- Centre for Cognitive Neuroscience, University of SalzburgSalzburg, Austria; Center for Mind/Brain Science, University of TrentoMattarello, Italy
| | - Christian Keitel
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow Glasgow, UK
| | - Chrysa Lithari
- Centre for Cognitive Neuroscience, University of Salzburg Salzburg, Austria
| | - Nathan Weisz
- Centre for Cognitive Neuroscience, University of Salzburg Salzburg, Austria
| | - Toralf Neuling
- Centre for Cognitive Neuroscience, University of Salzburg Salzburg, Austria
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48
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Heimrath K, Fiene M, Rufener KS, Zaehle T. Modulating Human Auditory Processing by Transcranial Electrical Stimulation. Front Cell Neurosci 2016; 10:53. [PMID: 27013969 PMCID: PMC4779894 DOI: 10.3389/fncel.2016.00053] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/18/2016] [Indexed: 12/31/2022] Open
Abstract
Transcranial electrical stimulation (tES) has become a valuable research tool for the investigation of neurophysiological processes underlying human action and cognition. In recent years, striking evidence for the neuromodulatory effects of transcranial direct current stimulation, transcranial alternating current stimulation, and transcranial random noise stimulation has emerged. While the wealth of knowledge has been gained about tES in the motor domain and, to a lesser extent, about its ability to modulate human cognition, surprisingly little is known about its impact on perceptual processing, particularly in the auditory domain. Moreover, while only a few studies systematically investigated the impact of auditory tES, it has already been applied in a large number of clinical trials, leading to a remarkable imbalance between basic and clinical research on auditory tES. Here, we review the state of the art of tES application in the auditory domain focussing on the impact of neuromodulation on acoustic perception and its potential for clinical application in the treatment of auditory related disorders.
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Affiliation(s)
| | | | | | - Tino Zaehle
- Department of Neurology, Otto-von-Guericke University MagdeburgMagdeburg, Germany
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49
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Transcranial electrical stimulation of the occipital cortex during visual perception modifies the magnitude of BOLD activity: A combined tES-fMRI approach. Neuroimage 2015; 140:110-7. [PMID: 26608246 DOI: 10.1016/j.neuroimage.2015.11.034] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 11/05/2015] [Accepted: 11/13/2015] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to investigate if the blood oxygenation level-dependent (BOLD) changes in the visual cortex can be used as biomarkers reflecting the online and offline effects of transcranial electrical stimulation (tES). Anodal transcranial direct current stimulation (tDCS) and 10Hz transcranial alternating current stimulation (tACS) were applied for 10min duration over the occipital cortex of healthy adults during the presentation of different visual stimuli, using a crossover, double-blinded design. Control experiments were also performed, in which sham stimulation as well as another electrode montage were used. Anodal tDCS over the visual cortex induced a small but significant further increase in BOLD response evoked by a visual stimulus; however, no aftereffect was observed. Ten hertz of tACS did not result in an online effect, but in a widespread offline BOLD decrease over the occipital, temporal, and frontal areas. These findings demonstrate that tES during visual perception affects the neuronal metabolism, which can be detected with functional magnetic resonance imaging (fMRI).
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50
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Mapping entrained brain oscillations during transcranial alternating current stimulation (tACS). Neuroimage 2015; 140:89-98. [PMID: 26481671 DOI: 10.1016/j.neuroimage.2015.10.024] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/08/2015] [Accepted: 10/09/2015] [Indexed: 11/20/2022] Open
Abstract
Transcranial alternating current stimulation (tACS), a non-invasive and well-tolerated form of electric brain stimulation, can influence perception, memory, as well as motor and cognitive function. While the exact underlying neurophysiological mechanisms are unknown, the effects of tACS are mainly attributed to frequency-specific entrainment of endogenous brain oscillations in brain areas close to the stimulation electrodes, and modulation of spike timing dependent plasticity reflected in gamma band oscillatory responses. tACS-related electromagnetic stimulator artifacts, however, impede investigation of these neurophysiological mechanisms. Here we introduce a novel approach combining amplitude-modulated tACS during whole-head magnetoencephalography (MEG) allowing for artifact-free source reconstruction and precise mapping of entrained brain oscillations underneath the stimulator electrodes. Using this approach, we show that reliable reconstruction of neuromagnetic low- and high-frequency oscillations including high gamma band activity in stimulated cortical areas is feasible opening a new window to unveil the mechanisms underlying the effects of stimulation protocols that entrain brain oscillatory activity.
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