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Lee TW, Li CSR, Tramontano G. Tripod transcranial alternating current stimulation at 5-Hz to alleviate anxiety symptoms: A preliminary report. J Affect Disord 2024; 360:156-162. [PMID: 38821364 DOI: 10.1016/j.jad.2024.05.166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 05/27/2024] [Accepted: 05/28/2024] [Indexed: 06/02/2024]
Abstract
INTRODUCTION One of the most common applications of transcranial electrical stimulation (tES) at low current intensity is to induce a relaxed state or reduce anxiety. With technical advancement, different waveforms, montages, and parameters can be incorporated into the treatment regimen. We developed a novel protocol to treat individuals with anxiety disorders by transcranial alternating current stimulation (tACS). METHODS A total of 27 individuals with anxiety disorders underwent tACS treatment for 12 sessions, with each session lasting 25 min. tACS at 5 Hz was applied to F4 (1.0 mA), P4 (1.0 mA), and T8 (2.0 mA) EEG lead positions (tripod), with sinewave oscillation between T8 and F4/P4. We evaluated the primary and secondary outcomes using the Beck Anxiety Inventory (BAI) and neuropsychological assessments. RESULTS Of the 27 patients, 19 (70.4 %) experienced a reduction in symptom severity >50 %, with an average reduction of BAI 58.5 %. All reported side effects were mild, with itching or tingling being the most common complaint. No significant differences were noted in attention, linguistic working memory, visuospatial working memory, or long-term memory in neuropsychological assessments. CONCLUSION The results suggest the potential of this novel tripod tACS design as a rapid anxiety alleviator and the importance of a clinical trial to verify its efficacy.
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Affiliation(s)
- Tien-Wen Lee
- The NeuroCognitive Institute (NCI) Clinical Research Foundation, NJ 07856, USA
| | - Chiang-Shan R Li
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA; Wu Tsai Institute, Yale University, New Haven, CT 06520, USA.
| | - Gerald Tramontano
- The NeuroCognitive Institute (NCI) Clinical Research Foundation, NJ 07856, USA.
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Gholamali Nezhad F, Martin J, Tassone VK, Swiderski A, Demchenko I, Khan S, Chaudhry HE, Palmisano A, Santarnecchi E, Bhat V. Transcranial alternating current stimulation for neuropsychiatric disorders: a systematic review of treatment parameters and outcomes. Front Psychiatry 2024; 15:1419243. [PMID: 39211537 PMCID: PMC11360874 DOI: 10.3389/fpsyt.2024.1419243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 07/17/2024] [Indexed: 09/04/2024] Open
Abstract
Background Transcranial alternating current stimulation (tACS) alters cortical excitability with low-intensity alternating current and thereby modulates aberrant brain oscillations. Despite the recent increase in studies investigating the feasibility and efficacy of tACS in treating neuropsychiatric disorders, its mechanisms, as well as optimal stimulation parameters, are not fully understood. Objectives This systematic review aimed to compile human research on tACS for neuropsychiatric disorders to delineate typical treatment parameters for these conditions and evaluate its outcomes. Methods A search for published studies and unpublished registered clinical trials was conducted through OVID (MEDLINE, PsycINFO, and Embase), ClinicalTrials.gov, and the International Clinical Trials Registry Platform. Studies utilizing tACS to treat neuropsychiatric disorders in a clinical trial setting were included. Results In total, 783 published studies and 373 clinical trials were screened; 53 published studies and 70 clinical trials were included. Published studies demonstrated a low risk of bias, as assessed by the Joanna Briggs Institute Critical Appraisal Tools. Neurocognitive, psychotic, and depressive disorders were the most common disorders treated with tACS. Both published studies (58.5%) and registered clinical trials (52%) most commonly utilized gamma frequency bands and tACS was typically administered at an intensity of 2 mA peak-to-peak, once daily for 20 or fewer sessions. Although the targeted brain locations and tACS montages varied across studies based on the outcome measures and specific pathophysiology of the disorders, the dorsolateral prefrontal cortex (DLPFC) was the most common target in both published studies (30.2%) and registered clinical trials (25.6%). Across studies that published results on tACS outcome measures, tACS resulted in enhanced symptoms and/or improvements in overall psychopathology for neurocognitive (all 11 studies), psychotic (11 out of 14 studies), and depressive (7 out of 8 studies) disorders. Additionally, 17 studies reported alterations in the power spectrum of the electroencephalogram around the entrained frequency band at the targeted locations following tACS. Conclusion Behavioral and cognitive symptoms have been positively impacted by tACS. The most consistent changes were reported in cognitive symptoms following gamma-tACS over the DLPFC. However, the paucity of neuroimaging studies for each neuropsychiatric condition highlights the necessity for replication studies employing biomarker- and mechanism-centric approaches.
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Affiliation(s)
- Fatemeh Gholamali Nezhad
- Interventional Psychiatry Program, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
| | - Josh Martin
- Interventional Psychiatry Program, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
| | - Vanessa K. Tassone
- Interventional Psychiatry Program, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Alyssa Swiderski
- Interventional Psychiatry Program, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
| | - Ilya Demchenko
- Interventional Psychiatry Program, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Institute of Biomedical Engineering, Science, and Technology (iBEST), Keenan Research Centre for Biomedical Science, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
| | - Somieya Khan
- Interventional Psychiatry Program, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
| | - Hamzah E. Chaudhry
- Interventional Psychiatry Program, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
| | - Annalisa Palmisano
- Precision Neuroscience and Neuromodulation Program, Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Chair of Lifespan Developmental Neuroscience, TUD Dresden University of Technology, Dresden, Germany
| | - Emiliano Santarnecchi
- Precision Neuroscience and Neuromodulation Program, Gordon Center for Medical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Venkat Bhat
- Interventional Psychiatry Program, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
- Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Institute of Biomedical Engineering, Science, and Technology (iBEST), Keenan Research Centre for Biomedical Science, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
- Neuroscience Research Program, St. Michael’s Hospital - Unity Health Toronto, Toronto, ON, Canada
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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Lee TW, Tramontano G. Neural consequences of 5-Hz transcranial alternating current stimulation over right hemisphere: An eLORETA EEG study. Neurosci Lett 2024; 835:137849. [PMID: 38825146 DOI: 10.1016/j.neulet.2024.137849] [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: 02/22/2024] [Revised: 05/06/2024] [Accepted: 05/30/2024] [Indexed: 06/04/2024]
Abstract
INTRODUCTION Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere can effectively alleviate anxiety symptoms. This study aimed to explore the neural mechanisms that drive the therapeutic benefits. METHODS We collected electroencephalography (EEG) data from 24 participants with anxiety disorders before and after a tACS treatment session. tACS was applied over the right hemisphere, with 1.0 mA at F4, 1.0 mA at P4, and 2.0 mA at T8 (10-10 EEG convention). With eLORETA, we transformed the scalp signals into the current source density in the cortex. We then assessed the differences between post- and pre-treatment brain maps across multiple spectra (delta to low gamma) with non-parametric statistics. RESULTS We observed a trend of heightened power in alpha and reduced power in mid-to-high beta and low gamma, in accord with the EEG markers of anxiolytic effects reported in previous studies. Additionally, we observed a consistent trend of de-synchronization at the stimulating sites across spectra. CONCLUSION tACS 5-Hz over the right hemisphere demonstrated EEG markers of anxiety reduction. The after-effects of tACS on the brain are intricate and cannot be explained solely by the widely circulated entrainment theory. Rather, our results support the involvement of plasticity mechanisms in the offline effects of tACS.
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Affiliation(s)
- Tien-Wen Lee
- The NeuroCognitive Institute (NCI) Clinical Research Foundation, NJ 07856, USA
| | - Gerald Tramontano
- The NeuroCognitive Institute (NCI) Clinical Research Foundation, NJ 07856, USA.
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Birreci D, De Riggi M, Costa D, Angelini L, Cannavacciuolo A, Passaretti M, Paparella G, Guerra A, Bologna M. The Role of Non-Invasive Brain Modulation in Identifying Disease Biomarkers for Diagnostic and Therapeutic Purposes in Parkinsonism. Brain Sci 2024; 14:695. [PMID: 39061435 PMCID: PMC11274666 DOI: 10.3390/brainsci14070695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 07/05/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024] Open
Abstract
Over the past three decades, substantial advancements have occurred in non-invasive brain stimulation (NIBS). These developments encompass various non-invasive techniques aimed at modulating brain function. Among the most widely utilized methods today are transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES), which include direct- or alternating-current transcranial stimulation (tDCS/tACS). In addition to these established techniques, newer modalities have emerged, broadening the scope of non-invasive neuromodulation approaches available for research and clinical applications in movement disorders, particularly for Parkinson's disease (PD) and, to a lesser extent, atypical Parkinsonism (AP). All NIBS techniques offer the opportunity to explore a wide range of neurophysiological mechanisms and exert influence over distinct brain regions implicated in the pathophysiology of Parkinsonism. This paper's first aim is to provide a brief overview of the historical background and underlying physiological principles of primary NIBS techniques, focusing on their translational relevance. It aims to shed light on the potential identification of biomarkers for diagnostic and therapeutic purposes, by summarising available experimental data on individuals with Parkinsonism. To date, despite promising findings indicating the potential utility of NIBS techniques in Parkinsonism, their integration into clinical routine for diagnostic or therapeutic protocols remains a subject of ongoing investigation and scientific debate. In this context, this paper addresses current unsolved issues and methodological challenges concerning the use of NIBS, focusing on the importance of future research endeavours for maximizing the efficacy and relevance of NIBS strategies for individuals with Parkinsonism.
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Affiliation(s)
- Daniele Birreci
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell’Università, 30, 00185 Rome, Italy; (D.B.); (M.D.R.); (M.P.); (G.P.)
| | - Martina De Riggi
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell’Università, 30, 00185 Rome, Italy; (D.B.); (M.D.R.); (M.P.); (G.P.)
| | - Davide Costa
- IRCCS Neuromed, Via Atinense, 18, 86077 Pozzilli, IS, Italy; (D.C.); (L.A.); (A.C.)
| | - Luca Angelini
- IRCCS Neuromed, Via Atinense, 18, 86077 Pozzilli, IS, Italy; (D.C.); (L.A.); (A.C.)
| | | | - Massimiliano Passaretti
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell’Università, 30, 00185 Rome, Italy; (D.B.); (M.D.R.); (M.P.); (G.P.)
- Department of Clinical Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Giulia Paparella
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell’Università, 30, 00185 Rome, Italy; (D.B.); (M.D.R.); (M.P.); (G.P.)
- IRCCS Neuromed, Via Atinense, 18, 86077 Pozzilli, IS, Italy; (D.C.); (L.A.); (A.C.)
| | - Andrea Guerra
- Parkinson and Movement Disorders Unit, Study Centre on Neurodegeneration (CESNE), Department of Neuroscience, University of Padua, 35121 Padua, Italy;
- Padova Neuroscience Centre (PNC), University of Padua, 35121 Padua, Italy
| | - Matteo Bologna
- Department of Human Neurosciences, Sapienza University of Rome, Viale dell’Università, 30, 00185 Rome, Italy; (D.B.); (M.D.R.); (M.P.); (G.P.)
- IRCCS Neuromed, Via Atinense, 18, 86077 Pozzilli, IS, Italy; (D.C.); (L.A.); (A.C.)
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Latrèche C, Mancini V, Rochas V, Maeder J, Cantonas LM, Férat V, Schneider M, Michel CM, Eliez S. Using transcranial alternating current stimulation to enhance working memory skills in youths with 22q11.2 deletion syndrome: A randomized double-blind sham-controlled study. Psychiatry Res 2024; 335:115835. [PMID: 38460352 DOI: 10.1016/j.psychres.2024.115835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 02/29/2024] [Accepted: 03/02/2024] [Indexed: 03/11/2024]
Abstract
Abnormal cognitive development, particularly working memory (WM) deficits, is among the first apparent manifestations of psychosis. Yet, cognitive impairment only shows limited response to current pharmacological treatment. Alternative interventions to target cognition are highly needed in individuals at high risk for psychosis, like carriers of 22q11.2 deletion syndrome (22q11.2DS). Here we applied theta-tuned transcranial alternating current stimulation (tACS) between frontal and temporal regions during a visual WM task in 34 deletion carriers. We conducted a double-blind sham-controlled study over three consecutive days. The stimulation parameters were derived from individual structural MRI scan and HD-EEG data acquired at baseline (Day 1) to model current intensity and individual preferential theta peak. Participants were randomized to either sham or tACS (Days 2 and 3) and then completed a visual WM task and a control task. Our findings reveal that tACS was safe and well-tolerated among participants. We found a significantly increased accuracy in the visual WM but not the control task following tACS. Moreover, this enhancement in WM accuracy was greater after tACS than during tACS, indicating stronger offline effects than online effects. Our study therefore supports the application of repeated sessions of brain stimulation in 22q11.2DS.
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Affiliation(s)
- Caren Latrèche
- Developmental Imaging and Psychopathology Lab, Department of Psychiatry, University of Geneva School of Medicine, Switzerland.
| | - Valentina Mancini
- Developmental Imaging and Psychopathology Lab, Department of Psychiatry, University of Geneva School of Medicine, Switzerland
| | - Vincent Rochas
- Functional Brain Mapping Laboratory, Department of Basic Neurosciences, University of Geneva, Switzerland; Human Neuroscience Platform, Fondation Campus Biotech Geneva, Geneva, Switzerland
| | - Johanna Maeder
- Developmental Imaging and Psychopathology Lab, Department of Psychiatry, University of Geneva School of Medicine, Switzerland
| | - Lucia M Cantonas
- Autism Brain and Behavior Laboratory, Department of Psychiatry, University of Geneva School of Medicine, Geneva, Switzerland
| | - Victor Férat
- Functional Brain Mapping Laboratory, Department of Basic Neurosciences, University of Geneva, Switzerland
| | - Maude Schneider
- Clinical Psychology Unit for Developmental and Intellectual Disabilities, Faculty of Psychology and Educational Sciences, University of Geneva, Switzerland
| | - Christoph M Michel
- Functional Brain Mapping Laboratory, Department of Basic Neurosciences, University of Geneva, Switzerland
| | - Stephan Eliez
- Developmental Imaging and Psychopathology Lab, Department of Psychiatry, University of Geneva School of Medicine, Switzerland; Department of Genetic Medicine and Development, University of Geneva School of Medicine, Switzerland
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Baselgia S, Kasten FH, Herrmann CS, Rasch B, Paβmann S. No Benefit in Memory Performance after Nocturnal Memory Reactivation Coupled with Theta-tACS. Clocks Sleep 2024; 6:211-233. [PMID: 38651390 PMCID: PMC11036246 DOI: 10.3390/clockssleep6020015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/14/2024] [Accepted: 03/19/2024] [Indexed: 04/25/2024] Open
Abstract
Targeted memory reactivation (TMR) is an effective technique to enhance sleep-associated memory consolidation. The successful reactivation of memories by external reminder cues is typically accompanied by an event-related increase in theta oscillations, preceding better memory recall after sleep. However, it remains unclear whether the increase in theta oscillations is a causal factor or an epiphenomenon of successful TMR. Here, we used transcranial alternating current stimulation (tACS) to examine the causal role of theta oscillations for TMR during non-rapid eye movement (non-REM) sleep. Thirty-seven healthy participants learned Dutch-German word pairs before sleep. During non-REM sleep, we applied either theta-tACS or control-tACS (23 Hz) in blocks (9 min) in a randomised order, according to a within-subject design. One group of participants received tACS coupled with TMR time-locked two seconds after the reminder cue (time-locked group). Another group received tACS in a continuous manner while TMR cues were presented (continuous group). Contrary to our predictions, we observed no frequency-specific benefit of theta-tACS coupled with TMR during sleep on memory performance, neither for continuous nor time-locked stimulation. In fact, both stimulation protocols blocked the TMR-induced memory benefits during sleep, resulting in no memory enhancement by TMR in both the theta and control conditions. No frequency-specific effect was found on the power analyses of the electroencephalogram. We conclude that tACS might have an unspecific blocking effect on memory benefits typically observed after TMR during non-REM sleep.
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Affiliation(s)
- Sandrine Baselgia
- Cognitive Biopsychology and Methods, Department of Psychology, Université de Fribourg, 1700 Fribourg, Switzerland;
| | - Florian H. Kasten
- Centre de Recherche Cerveau & Cognition, CNRS & Université Toulouse III Paul Sabatier, 31062 Toulouse, France;
| | - Christoph S. Herrmann
- Experimental Psychology Lab, Department of Psychology, Carl von Ossietzky Universität, 26129 Oldenburg, Germany;
| | - Björn Rasch
- Cognitive Biopsychology and Methods, Department of Psychology, Université de Fribourg, 1700 Fribourg, Switzerland;
| | - Sven Paβmann
- Cognitive Biopsychology and Methods, Department of Psychology, Université de Fribourg, 1700 Fribourg, Switzerland;
- Department of Neurology, University Medicine Greifswald, 17475 Greifswald, Germany
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Zhang HY, Hou TT, Jin ZH, Zhang T, Wang YH, Cheng ZH, Liu YH, Fang JP, Yan HJ, Zhen Y, An X, Du J, Chen KK, Li ZZ, Li Q, Wen QP, Fang BY. Transcranial alternating current stimulation improves quality of life in Parkinson's disease: study protocol for a randomized, double-blind, controlled trial. Trials 2024; 25:200. [PMID: 38509589 PMCID: PMC10953283 DOI: 10.1186/s13063-024-08045-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 03/08/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND The neural cells in the brains of patients with Parkinson's disease (PWP) display aberrant synchronized oscillatory activity within the beta frequency range. Additionally, enhanced gamma oscillations may serve as a compensatory mechanism for motor inhibition mediated by beta activity and also reinstate plasticity in the primary motor cortex affected by Parkinson's disease. Transcranial alternating current stimulation (tACS) can synchronize endogenous oscillations with exogenous rhythms, thereby modulating cortical activity. The objective of this study is to investigate whether the addition of tACS to multidisciplinary intensive rehabilitation treatment (MIRT) can improve symptoms of PWP so as to enhance the quality of life in individuals with Parkinson's disease based on the central-peripheral-central theory. METHODS The present study was a randomized, double-blind trial that enrolled 60 individuals with Parkinson's disease aged between 45 and 70 years, who had Hoehn-Yahr scale scores ranging from 1 to 3. Participants were randomly assigned in a 1:1 ratio to either the tACS + MIRT group or the sham-tACS + MIRT group. The trial consisted of a two-week double-blind treatment period followed by a 24-week follow-up period, resulting in a total duration of twenty-six weeks. The primary outcome measured the change in PDQ-39 scores from baseline (T0) to 4 weeks (T2), 12 weeks (T3), and 24 weeks (T4) after completion of the intervention. The secondary outcome assessed changes in MDS-UPDRS III scores at T0, the end of intervention (T1), T2, T3, and T4. Additional clinical assessments and mechanistic studies were conducted as tertiary outcomes. DISCUSSION The objective of this study is to demonstrate that tACS can enhance overall functionality and improve quality of life in PWP, based on the framework of MIRT. Additionally, it seeks to establish a potential correlation between these therapeutic effects and neuroplasticity alterations in relevant brain regions. The efficacy of tACS will be assessed during the follow-up period in order to optimize neuroplasticity and enhance its potential impact on rehabilitation efficiency for PWP. TRIAL REGISTRATION Chinese Clinical Trial Registry ChiCTR2300071969. Registered on 30 May 2023.
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Affiliation(s)
- Hong-Yu Zhang
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
- Capital Medical University, Beijing, China
| | - Ting-Ting Hou
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
- Capital Medical University, Beijing, China
| | - Zhao-Hui Jin
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Tian Zhang
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
- Capital Medical University, Beijing, China
| | - Yi-Heng Wang
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
- Capital Medical University, Beijing, China
| | - Zi-Hao Cheng
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
- Capital Medical University, Beijing, China
| | - Yong-Hong Liu
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Jin-Ping Fang
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Hong-Jiao Yan
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Yi Zhen
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Xia An
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Jia Du
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Ke-Ke Chen
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Zhen-Zhen Li
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Qing Li
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Qi-Ping Wen
- Radiology Department, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China
| | - Bo-Yan Fang
- Parkinson Medical Center, Beijing Rehabilitation Hospital, Capital Medical University, Badachu, Xixiazhuang, Shijingshan District, Bejing, 100144, China.
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Fujiyama H, Williams A, Tan J, Levin O, Hinder MR. Comparison of online and offline applications of dual-site transcranial alternating current stimulation (tACS) over the pre-supplementary motor area (preSMA) and right inferior frontal gyrus (rIFG) for improving response inhibition. Neuropsychologia 2023; 191:108737. [PMID: 37995902 DOI: 10.1016/j.neuropsychologia.2023.108737] [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: 07/17/2023] [Revised: 09/25/2023] [Accepted: 11/16/2023] [Indexed: 11/25/2023]
Abstract
The efficacy of transcranial alternating current stimulation (tACS) is thought to be brain state-dependent, such that tACS during task performance would be hypothesised to offer greater potential for improving performance compared to tACS at rest. However, to date, no empirical study has tested this postulation. The current study compared the effects of dual-site beta tACS applied during a stop signal task (online) to the effects of the same tACS protocol applied prior to the task (offline) and a sham control stimulation in 53 young, healthy adults (32 female; 18-35 yrs). The right inferior frontal gyrus (rIFG) and centre (midline) of the pre-supplementary motor area (preSMA), which are thought to play critical roles in action cancellation, were simultaneously stimulated, sending phase-synchronised stimulation for 15 min with the aim of increasing functional connectivity. The offline group showed significant within-group improvement in response inhibition without showing overt task-related changes in functional connectivity measured with EEG connectivity analysis, suggesting offline tACS is efficacious in inducing behavioural changes potentially via a post-stimulation early plasticity mechanism. In contrast, neither the online nor sham group showed significant improvements in response inhibition. However, EEG connectivity analysis revealed significantly increased task-related functional connectivity following online stimulation and a medium effect size observed in correlation analyses suggested that an increase in functional connectivity in the beta band at rest was potentially associated with an improvement in response inhibition. Overall, the results indicate that both online and offline dual-site beta tACS can be beneficial in improving inhibitory control via distinct underlying mechanisms.
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Affiliation(s)
- Hakuei Fujiyama
- School of Psychology, Murdoch University, Western Australia, Australia; Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Western Australia, Australia; Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Western Australia, Australia.
| | | | - Jane Tan
- School of Psychology, Murdoch University, Western Australia, Australia; Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Western Australia, Australia
| | - Oron Levin
- Department of Health Promotion and Rehabilitation, Lithuanian Sports University, Kaunas, Lithuania; Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, Catholic University Leuven, Leuven, Belgium
| | - Mark R Hinder
- Sensorimotor Neuroscience and Ageing Research Group, School of Psychological Sciences, College of Health and Medicine, University of Tasmania, Tasmania, Australia
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Dantas AM, Sack AT, Bruggen E, Jiao P, Schuhmann T. Modulating risk-taking behavior with theta-band tACS. Neuroimage 2023; 283:120422. [PMID: 37884165 DOI: 10.1016/j.neuroimage.2023.120422] [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: 04/03/2023] [Revised: 08/31/2023] [Accepted: 10/23/2023] [Indexed: 10/28/2023] Open
Abstract
Although risk is prevalent in decision-making, the specific neural processes underlying risk-taking behavior remain unclear. Previous studies have suggested that frontal theta-band activity plays a crucial role in modulating risk-taking behavior. The functional relevance of theta in risk-taking behavior is yet to be clearly established and studies using noninvasive brain stimulation have yielded inconsistent findings. We aimed to investigate this relevance using transcranial alternating current stimulation (tACS) over right or left dorsolateral prefrontal cortex (DLPFC). We also studied the influence of stimulation intensity on risk-taking behavior and electrophysiological effects. We applied theta-band (6.5 Hz) tACS over the left (F3) and right (F4) DLPFC with lower (1.5 mA) and higher (3 mA) tACS intensities. We employed a single-blinded, sham-controlled, within-subject design and combined tACS with electroencephalography (EEG) measurements and the Maastricht Gambling Task (MGT) to elicit and evaluate risk-taking behavior. Our results show an increase in risk-taking behavior after left DLPFC stimulation at both intensities and a reduction of risk-taking behavior after 3 mA (and not 1.5 mA) right DLPFC stimulation compared to sham. Further analyses showed a negative correlation between resting-state frontal theta-power and risk-taking behavior. Overall, frontal theta-power was increased after left, but not right, theta-band tACS independent of stimulation intensity. Our findings confirm the functional relevance of frontal theta-band activity in decision-making under risk and the differential role of left and right DLPFC. We also were able to show that stimulation intensity did have an effect on behavioral responses, namely risk-taking behavior. Significant right hemisphere stimulation effects were observed only after high-intensity stimulation. Nevertheless, electrophysiological effects were only significant after left DLPFC stimulation, regardless of tACS intensity. Furthermore, the results indicate the role of the baseline frontal theta-power in the direction of behavioral effects after theta-band tACS.
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Affiliation(s)
- Aline M Dantas
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University. Oxfordlaan 55, 6229 EV, Maastricht, the Netherlands; Maastricht Brain Imaging Center, Maastricht University. Oxfordlaan 55, 6229 EV, Maastricht, the Netherlands; Department of Psychiatry and Neuropsychology, School for Mental Health, and Neuroscience (MHeNs), Brain+Nerve Center, Maastricht University Medical Center+ (MUMC+). P. Debyelaan 25, 6229 HX, Maastricht, the Netherlands.
| | - Alexander T Sack
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University. Oxfordlaan 55, 6229 EV, Maastricht, the Netherlands; Maastricht Brain Imaging Center, Maastricht University. Oxfordlaan 55, 6229 EV, Maastricht, the Netherlands; Department of Psychiatry and Neuropsychology, School for Mental Health, and Neuroscience (MHeNs), Brain+Nerve Center, Maastricht University Medical Center+ (MUMC+). P. Debyelaan 25, 6229 HX, Maastricht, the Netherlands
| | - Elisabeth Bruggen
- Department of Marketing and Supply Chain Management, School of Business and Economics, Maastricht University. P.O. Box 616, 6200 MD, Maastricht, the Netherlands; BISS - Brightlands Institute for Smart Society, Maastricht University, Heerlen, the Netherlands; Netspar - Network for Studies on Pension, Aging and Retirement
| | - Peiran Jiao
- Department of Finance, School of Business and Economics, Maastricht University. P.O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - Teresa Schuhmann
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University. Oxfordlaan 55, 6229 EV, Maastricht, the Netherlands; Maastricht Brain Imaging Center, Maastricht University. Oxfordlaan 55, 6229 EV, Maastricht, the Netherlands
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10
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Rufener KS, Zaehle T, Krauel K. Combined multi-session transcranial alternating current stimulation (tACS) and language skills training improves individual gamma band activity and literacy skills in developmental dyslexia. Dev Cogn Neurosci 2023; 64:101317. [PMID: 37898018 PMCID: PMC10630593 DOI: 10.1016/j.dcn.2023.101317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/12/2023] [Accepted: 10/17/2023] [Indexed: 10/30/2023] Open
Abstract
Developmental dyslexia is characterized by the pathologically diminished ability to acquire reading and spelling skills. Accurate processing of acoustic information at the phonemic scale is crucial for successful sound-to-letter-mapping which, in turn, is elemental in reading and spelling. Altered activation patterns in the auditory cortex are thought to provide the neurophysiological basis for the inaccurate phonemic perception. Recently, transcranial electrical stimulation has been shown to be an effective method to ameliorate cortical activation patterns in the auditory cortex. In a sample of children and adolescents with dyslexia, we investigated the effect of multi-session transcranial alternating current stimulation delivered concurrently with a phonological training and in combination with a behavioral literacy skills training. Over a 5-week period the participants received 10 training sessions while gamma-tACS was administered over bilateral auditory cortex. We found that gamma-tACS shifted the peak frequency of auditory gamma oscillations reflecting a more fine-grained processing of time-critical acoustic information. This amelioration was accompanied by increased phonemic processing skills. Moreover, individuals who received gamma-tACS showed significant improvements in their spelling skills four months after the intervention. Our results demonstrate that multi-session gamma-tACS enhances the effects of a behavioral intervention and induces long-term improvement on literacy skills in dyslexia.
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Affiliation(s)
- Katharina S Rufener
- Department of Child and Adolescent Psychiatry and Psychotherapy, Otto-von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany; DZPG (German Center for Mental Health), partner site Halle-Jena, Magdeburg, Germany.
| | - Tino Zaehle
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany; Department of Medical Psychology, Otto-von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany; DZPG (German Center for Mental Health), partner site Halle-Jena, Magdeburg, Germany
| | - Kerstin Krauel
- Department of Child and Adolescent Psychiatry and Psychotherapy, Otto-von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Magdeburg, Germany; DZPG (German Center for Mental Health), partner site Halle-Jena, Magdeburg, Germany
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11
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Park J, Lee S, Park S, Lee C, Kim S, Im CH. Transcranial alternating current stimulation over multiple brain areas with non-zero phase delays other than 180 degrees modulates visuospatial working memory performance. Sci Rep 2023; 13:12710. [PMID: 37543713 PMCID: PMC10404219 DOI: 10.1038/s41598-023-39960-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 08/02/2023] [Indexed: 08/07/2023] Open
Abstract
While zero-phase lag synchronization between multiple brain regions has been widely observed, relatively recent reports indicate that systematic phase delays between cortical regions reflect the direction of communications between cortical regions. For example, it has been suggested that a non-zero phase delay of electroencephalography (EEG) signals at the gamma frequency band between the bilateral parietal areas may reflect the direction of communication between these areas. We hypothesized that the direction of communication between distant brain areas might be modulated by multi-site transcranial alternating current stimulation (tACS) with specific phase delays other than 0° and 180°. In this study, a new noninvasive brain stimulation (NIBS) method called multi-site multi-phase tACS (msmp-tACS) was proposed. The efficacy of the proposed method was tested in a case study using a visuospatial working memory (VWM) paradigm in which the optimal stimulation conditions including amplitudes and phases of multiple scalp electrodes were determined using finite element analysis adopting phasor representation. msmp-tACS was applied over the bilateral intraparietal sulci (IPS) and showed that 80 Hz tACS with the phase for the right IPS leading that for the left IPS by 90° (= 3.125 ms) partialized VWM performance toward the right visual hemifield. The three stimulation conditions were synchronized, RL, and LR, which refers to stimulation condition with no phase lag, stimulation phase of right IPS (rIPS) leading left IPS (lIPS) by 90° and the stimulation of lIPS leading rIPS by 90°, respectively. The lateralization of VWM significantly shifted towards right visual hemifield under the RL condition compared to the synchronized and LR conditions. The shift in VWM was the result of the stimulation affecting both left and right visual hemifield trials to certain degrees, rather than significantly increasing or decreasing VWM capacity of a specific visual hemifield. Altered brain dynamics caused by msmp-tACS partialized VWM performance, likely due to modulation of effective connectivity between the rIPS and lIPS. Our results suggest that msmp-tACS is a promising NBS method that can effectively modulate cortical networks that cannot be readily modulated with conventional multi-site stimulation methods.
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Affiliation(s)
- Jimin Park
- Department of Electronic Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Republic of Korea
| | - Sangjun Lee
- Department of Electronic Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Republic of Korea
| | - Seonghun Park
- Department of Electronic Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Republic of Korea
| | - Chany Lee
- Cognitive Science Research Group, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Sungshin Kim
- Department of Cognitive Sciences, Hanyang University, Seoul, Republic of Korea
| | - Chang-Hwan Im
- Department of Electronic Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Republic of Korea.
- Department of Biomedical Engineering, Hanyang University, Seoul, Republic of Korea.
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12
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Lyzhko E, Peter SE, Nees F, Siniatchkin M, Moliadze V. Offline 20 Hz transcranial alternating current stimulation over the right inferior frontal gyrus increases theta activity during a motor response inhibition task. Neurophysiol Clin 2023; 53:102887. [PMID: 37355398 DOI: 10.1016/j.neucli.2023.102887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/17/2023] [Accepted: 05/17/2023] [Indexed: 06/26/2023] Open
Abstract
OBJECTIVES Previous studies have shown that the right inferior frontal gyrus (rIFG) and the pre-supplementary motor area (preSMA) play an important role in motor inhibitory control. The aim of the study was to use theta frequency transcranial alternating current stimulation (tACS) to modulate brain activity in the rIFG and preSMA and to test the effects of stimulation using a motor response inhibition task. METHODS In four sessions, 20 healthy participants received tACS at 6 Hz over preSMA or rIFG, or 20 Hz over rIFG (to test frequency specificity), or sham stimulation before task processing. After each type of stimulation, the participants performed the Go/NoGo task with simultaneous electroencephalogram (EEG) recording. RESULTS By stimulating rIFG and preSMA with 6 Hz tACS, we were not able to modulate either behavioral performance nor the EEG correlate. Interestingly, 20 Hz tACS over the rIFG significantly increased theta activity, however without behavioral effects. This increased theta activity did not coincide with the stimulation area and was localized in the fronto-central and centro-parietal areas. CONCLUSIONS The inclusion of a control frequency is crucial to test for frequency specificity. Our findings are in accordance with previous studies showing that after effects of tACS are not restricted to the stimulation frequency but can also occur in other frequency bands.
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Affiliation(s)
- Ekaterina Lyzhko
- Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany; Department of Neuropediatrics, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany
| | - Stefanie E Peter
- Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany
| | - Frauke Nees
- Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany
| | - Michael Siniatchkin
- Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany; University Clinic of Child and Adolescent Psychiatry and Psychotherapy, University Hospital OWL, University of Bielefeld, Campus Bethel, Bielefeld, Germany
| | - Vera Moliadze
- Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany.
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Nissim NR, Pham DVH, Poddar T, Blutt E, Hamilton RH. The impact of gamma transcranial alternating current stimulation (tACS) on cognitive and memory processes in patients with mild cognitive impairment or Alzheimer's disease: A literature review. Brain Stimul 2023; 16:748-755. [PMID: 37028756 PMCID: PMC10862495 DOI: 10.1016/j.brs.2023.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 03/16/2023] [Accepted: 04/02/2023] [Indexed: 04/08/2023] Open
Abstract
BACKGROUND Transcranial alternating current stimulation (tACS)-a noninvasive brain stimulation technique that modulates cortical oscillations through entrainment-has been demonstrated to alter oscillatory activity and enhance cognition in healthy adults. TACS is being explored as a tool to improve cognition and memory in patient populations with mild cognitive impairment (MCI) and Alzheimer's disease (AD). OBJECTIVE To review the growing body of literature and current findings obtained from the application of tACS in patients with MCI or AD, highlighting the effects of gamma tACS on brain function, memory, and cognition. Evidence on the use of brain stimulation in animal models of AD is also discussed. Important parameters of stimulation are underscored for consideration in protocols that aim to apply tACS as a therapeutic tool in patients with MCI/AD. FINDINGS The application of gamma tACS has shown promising results in the improvement of cognitive and memory processes that are impacted in patients with MCI/AD. These data demonstrate the potential for tACS as an interventional stand-alone tool or alongside pharmacological and/or other behavioral interventions in MCI/AD. CONCLUSIONS While the use of tACS in MCI/AD has evidenced encouraging results, the effects of this stimulation technique on brain function and pathophysiology in MCI/AD remains to be fully determined. This review explores the literature and highlights the need for continued research on tACS as a tool to alter the course of the disease by reinstating oscillatory activity, improving cognitive and memory processing, delaying disease progression, and remediating cognitive abilities in patients with MCI/AD.
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Affiliation(s)
- N R Nissim
- Laboratory for Cognition and Neural Stimulation, Department of Neurology, University of Pennsylvania, Pennsylvania, PA, USA; Moss Rehabilitation Research Institute, Einstein Medical Center, Elkins Park, PA, USA.
| | - D V H Pham
- Laboratory for Cognition and Neural Stimulation, Department of Neurology, University of Pennsylvania, Pennsylvania, PA, USA
| | - T Poddar
- Laboratory for Cognition and Neural Stimulation, Department of Neurology, University of Pennsylvania, Pennsylvania, PA, USA
| | - E Blutt
- Laboratory for Cognition and Neural Stimulation, Department of Neurology, University of Pennsylvania, Pennsylvania, PA, USA
| | - R H Hamilton
- Laboratory for Cognition and Neural Stimulation, Department of Neurology, University of Pennsylvania, Pennsylvania, PA, USA; Moss Rehabilitation Research Institute, Einstein Medical Center, Elkins Park, PA, USA.
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14
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Very low-frequency transcranial electrical stimulation over the primary motor area can influence the voluntary movement initiation in humans. Brain Stimul 2023; 16:442-444. [PMID: 36736619 DOI: 10.1016/j.brs.2023.01.1679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 01/29/2023] [Indexed: 02/04/2023] Open
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15
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Lee TL, Lee H, Kang N. A meta-analysis showing improved cognitive performance in healthy young adults with transcranial alternating current stimulation. NPJ SCIENCE OF LEARNING 2023; 8:1. [PMID: 36593247 PMCID: PMC9807644 DOI: 10.1038/s41539-022-00152-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation used for improving cognitive functions via delivering weak electrical stimulation with a certain frequency. This systematic review and meta-analysis investigated the effects of tACS protocols on cognitive functions in healthy young adults. We identified 56 qualified studies that compared cognitive functions between tACS and sham control groups, as indicated by cognitive performances and cognition-related reaction time. Moderator variable analyses specified effect size according to (a) timing of tACS, (b) frequency band of simulation, (c) targeted brain region, and (b) cognitive domain, respectively. Random-effects model meta-analysis revealed small positive effects of tACS protocols on cognitive performances. The moderator variable analyses found significant effects for online-tACS with theta frequency band, online-tACS with gamma frequency band, and offline-tACS with theta frequency band. Moreover, cognitive performances were improved in online- and offline-tACS with theta frequency band on either prefrontal and posterior parietal cortical regions, and further both online- and offline-tACS with theta frequency band enhanced executive function. Online-tACS with gamma frequency band on posterior parietal cortex was effective for improving cognitive performances, and the cognitive improvements appeared in executive function and perceptual-motor function. These findings suggested that tACS protocols with specific timing and frequency band may effectively improve cognitive performances.
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Affiliation(s)
- Tae Lee Lee
- Department of Human Movement Science, Incheon National University, Incheon, South Korea
- Neuromechanical Rehabilitation Research Laboratory, Incheon National University, Incheon, South Korea
| | - Hanall Lee
- Department of Human Movement Science, Incheon National University, Incheon, South Korea
- Neuromechanical Rehabilitation Research Laboratory, Incheon National University, Incheon, South Korea
| | - Nyeonju Kang
- Department of Human Movement Science, Incheon National University, Incheon, South Korea.
- Neuromechanical Rehabilitation Research Laboratory, Incheon National University, Incheon, South Korea.
- Division of Sport Science & Sport Science Institute, Incheon National University, Incheon, South Korea.
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10 Minutes Frontal 40 Hz tACS-Effects on Working Memory Tested by Luck-Vogel Task. Behav Sci (Basel) 2022; 13:bs13010039. [PMID: 36661611 PMCID: PMC9855106 DOI: 10.3390/bs13010039] [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: 11/20/2022] [Revised: 12/21/2022] [Accepted: 12/27/2022] [Indexed: 01/03/2023] Open
Abstract
Working memory is a cognitive process that involves short-term active maintenance, flexible updating, and processing of goal- or task-relevant information. All frequency bands are involved in working memory. The activities of the theta and gamma frequency bands in the frontoparietal network are highly involved in working memory processes; theta oscillations play a role in the temporal organization of working memory items, and gamma oscillations influence the maintenance of information in working memory. Transcranial alternating current stimulation (tACS) results in frequency-specific modulation of endogenous oscillations and has shown promising results in cognitive neuroscience. The electrophysiological and behavioral changes induced by the modulation of endogenous gamma frequency in the prefrontal cortex using tACS have not been extensively studied in the context of working memory. Therefore, we aimed to investigate the effects of frontal gamma-tACS on working memory outcomes. We hypothesized that a 10-min gamma tACS administered over the frontal cortex would significantly improve working memory outcomes. Young healthy participants performed Luck-Vogel cognitive behavioral tasks with simultaneous pre- and post-intervention EEG recording (Sham versus 40 Hz tACS). Data from forty-one participants: sham (15 participants) and tACS (26 participants), were used for the statistical and behavioral analysis. The relative changes in behavioral outcomes and EEG due to the intervention were analyzed. The results show that tACS caused an increase in the power spectral density in the high beta and low gamma EEG bands and a decrease in left-right coherence. On the other hand, tACS had no significant effect on success rates and response times. Conclusion: 10 min of frontal 40 Hz tACS was not sufficient to produce detectable behavioral effects on working memory, whereas electrophysiological changes were evident. The limitations of the current stimulation protocol and future directions are discussed in detail in the following sections.
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Nakazono H, Taniguchi T, Mitsutake T, Takeda A, Yamada E, Ogata K. Phase-dependent modulation of the vestibular-cerebellar network via combined alternating current stimulation influences human locomotion and posture. Front Neurosci 2022; 16:1057021. [PMID: 36590300 PMCID: PMC9795064 DOI: 10.3389/fnins.2022.1057021] [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: 09/29/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022] Open
Abstract
Background Human locomotion induces rhythmic movements of the trunk and head. Vestibular signaling is relayed to multiple regions in the brainstem and cerebellum, and plays an essential role in maintaining head stability. However, how the vestibular-cerebellar network contributes to the rhythmic locomotor pattern in humans is unclear. Transcranial alternating current stimulation (tACS) has been used to investigate the effects of the task-related network between stimulation regions in a phase-dependent manner. Here, we investigated the relationship between the vestibular system and the cerebellum during walking imagery using combined tACS over the left cerebellum and alternating current galvanic vestibular stimulation (AC-GVS). Methods In Experiment 1, we tested the effects of AC-GVS alone at around individual gait stride frequencies. In Experiment 2, we then determined the phase-specificity of combined stimulation at the gait frequency. Combined stimulation was applied at in-phase (0° phase lag) or anti-phase (180° phase lag) between the left vestibular and left cerebellar stimulation, and the sham stimulation. We evaluated the AC-GVS-induced periodic postural response during walking imagery or no-imagery using the peak oscillatory power on the angular velocity signals of the head in both experiments. In Experiment 2, we also examined the phase-locking value (PLV) between the periodic postural responses and the left AC-GVS signals to estimate entrainment of the postural response by AC-GVS. Results AC-GVS alone induced the periodic postural response in the yaw and roll axes, but no interactions with imagery walking were observed in Experiment 1 (p > 0.05). By contrast, combined in-phase stimulation increased yaw motion (0.345 ± 0.23) compared with sham (-0.044 ± 0.19) and anti-phase stimulation (-0.066 ± 0.18) during imaginary walking (in-phase vs. other conditions, imagery: p < 0.05; no-imagery: p ≥ 0.125). Furthermore, there was a positive correlation between the yaw peak power of actual locomotion and in-phase stimulation in the imagery session (imagery: p = 0.041; no-imagery: p = 0.177). Meanwhile, we found no imagery-dependent effects in roll peak power or PLV, although in-phase stimulation enhanced roll motion and PLV in Experiment 2. Conclusion These findings suggest that combined stimulation can influence vestibular-cerebellar network activity, and modulate postural control and locomotion systems in a temporally sensitive manner. This novel combined tACS/AC-GVS stimulation approach may advance development of therapeutic applications.
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Affiliation(s)
- Hisato Nakazono
- Department of Occupational Therapy, Faculty of Medical Science, Fukuoka International University of Health and Welfare, Fukuoka, Japan,Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan,*Correspondence: Hisato Nakazono,
| | - Takanori Taniguchi
- Department of Physical Therapy, Faculty of Medical Science, Fukuoka International University of Health and Welfare, Fukuoka, Japan
| | - Tsubasa Mitsutake
- Department of Physical Therapy, Faculty of Medical Science, Fukuoka International University of Health and Welfare, Fukuoka, Japan
| | - Akinori Takeda
- Research Center for Brain Communication, Research Institute, Kochi University of Technology, Kochi, Japan
| | - Emi Yamada
- Department of Linguistics, Faculty of Humanities, Kyushu University, Fukuoka, Japan
| | - Katsuya Ogata
- Department of Pharmaceutical Sciences, School of Pharmacy at Fukuoka, International University of Health and Welfare, Fukuoka, Japan
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Zhang DW, Moraidis A, Klingberg T. Individually tuned theta HD-tACS improves spatial performance. Brain Stimul 2022; 15:1439-1447. [PMID: 36328341 DOI: 10.1016/j.brs.2022.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/12/2022] [Accepted: 10/27/2022] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Using transcranial alternating current stimulation (tACS) to improve visuospatial working memory (vsWM) has received considerable attention over the past few years. However, fundamental issues remain, such as the optimal frequency, the generality of behavioral effects, and the anatomical specificity of stimulation. OBJECTIVES Here we examined the effects of two theory-driven tACS protocols for improving vsWM on behavioral and electroencephalogram (EEG) measures. METHODS Twenty adults each completed 3 HD-tACS conditions (Tuned, Slow, and Sham) on two separate days. The Tuned condition refers to a situation in which the frequency of tACS is tuned to individual theta peak measured during a vsWM task. By contrast, the frequency was fixed to 4 Hz in the Slow condition. A high-definition tACS was deployed to target smaller frontal and parietal regions for increasing their phase-locking values. During each tACS condition, participants performed vsWM, mental rotation (MR), and arithmetic tasks. Resting-state EEG (rs-EEG) was recorded before and after each condition. RESULTS Compared with Sham, Tuned but not Slow improved both vsWM and MR but not arithmetics. The rs-EEG recording showed an increased fronto-parietal synchrony for Tuned, and this increase in synchronicity was correlated with the behavioral improvement. A follow-up study showed no behavioral improvement in Tuned with an anti-phase setting. CONCLUSION We provide the first evidence that simulating right fronto-parietal network with the tuned frequency increases the interregional synchronicity and improves performance on two spatial tasks. The results provide insight into the structure of spatial abilities as well as suggestions for stimulating the fronto-parietal network.
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Affiliation(s)
- Da-Wei Zhang
- Department of Psychology, Yangzhou University, Yangzhou, 225000, China; Department of Neuroscience, Karolinska Institutet, Stockholm, 17177, Sweden.
| | | | - Torkel Klingberg
- Department of Neuroscience, Karolinska Institutet, Stockholm, 17177, Sweden.
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Zhu HQ, Luo J, Wang XQ, Zhang XA. Non-invasive brain stimulation for osteoarthritis. Front Aging Neurosci 2022; 14:987732. [PMID: 36247995 PMCID: PMC9557732 DOI: 10.3389/fnagi.2022.987732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/26/2022] [Indexed: 11/13/2022] Open
Abstract
Osteoarthritis (OA) is a degenerative joint disease, the prevalence of OA is increasing, and the elderly are the most common in patients with OA. OA has a severe impact on the daily life of patients, this increases the demand for treatment of OA. In recent years, the application of non-invasive brain stimulation (NIBS) has attracted extensive attention. It has been confirmed that NIBS plays an important role in regulating cortical excitability and oscillatory rhythm in specific brain regions. In this review, we summarized the therapeutic effects and mechanisms of different NIBS techniques in OA, clarified the potential of NIBS as a treatment choice for OA, and provided prospects for further research in the future.
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Affiliation(s)
- Hui-Qi Zhu
- College of Kinesiology, Shenyang Sport University, Shenyang, China
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China
| | - Jing Luo
- Department of Sport Rehabilitation, Xi’an University of Sport, Xi’an, China
| | - Xue-Qiang Wang
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China
- Department of Rehabilitation Medicine, Shanghai Shangti Orthopaedic Hospital, Shanghai, China
- Xue-Qiang Wang,
| | - Xin-An Zhang
- College of Kinesiology, Shenyang Sport University, Shenyang, China
- *Correspondence: Xin-An Zhang,
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Sale MV, Kuzovina A. Motor training is improved by concurrent application of slow oscillating transcranial alternating current stimulation to motor cortex. BMC Neurosci 2022; 23:45. [PMID: 35840886 PMCID: PMC9287859 DOI: 10.1186/s12868-022-00731-x] [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: 03/21/2022] [Accepted: 07/04/2022] [Indexed: 11/17/2022] Open
Abstract
Physical exercise and neurorehabilitation involve repetitive training that can induce changes in motor performance arising from neuroplasticity. Retention of these motor changes occurs via an encoding process, during which rapid neuroplastic changes occur in response to training. Previous studies show that transcranial alternating current stimulation (tACS), a form of non-invasive brain stimulation, can enhance encoding of a cognitive learning task during wakefulness. However, the effect of tACS on motor processes in the awake brain is unknown. In this study, forty-two healthy 18–35 year old participants received either 0.75 Hz (active) tACS (or sham stimulation) for 30 min during a ballistic thumb abduction motor training task. Training-related behavioural effects were quantified by assessing changes in thumb abduction acceleration, and neuroplastic changes were quantified by measuring motor evoked potential (MEP) amplitude of the abductor pollicis brevis muscle. These measures were reassessed immediately after the motor training task to quantify short-term changes, and then 24 h later to assess longer-term changes. Thumb abduction acceleration in both active and sham stimulation conditions increased immediately after the motor learning, consistent with effective training. Critically, participants in the active group maintained significantly higher thumb acceleration 24 h later (t40 = 2.810, P = 0.044). There were no significant changes or inter-group differences in MEPs for both conditions. The results suggest that 0.75 Hz tACS applied during motor training enhances the effectiveness of motor training, which manifests as enhancement in longer-term task benefits.
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Affiliation(s)
- Martin V Sale
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia.
| | - Anastasiia Kuzovina
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Brisbane, QLD, 4072, Australia
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21
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No effects of prefrontal multichannel tACS at individual alpha frequency on phonological decisions. Clin Neurophysiol 2022; 142:96-108. [DOI: 10.1016/j.clinph.2022.07.494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 05/23/2022] [Accepted: 07/17/2022] [Indexed: 11/23/2022]
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22
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Farcas A, Iftene F. Findings, limitations and new directions in tACS studies in schizophrenia research: A scoping review. J Psychiatr Res 2022; 151:291-298. [PMID: 35525231 DOI: 10.1016/j.jpsychires.2022.04.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 04/13/2022] [Accepted: 04/25/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Schizophrenia (SZ) is a severe neurodevelopmental spectrum disorder with significant consequences for the individual who is diagnosed and their family, resulting in notable system-level costs associated with the current methods of treatment. With a complex etiology, this syndrome continues to evade our thorough understanding and invites cautious analysis into how the newest research findings may translate into meaningful interventions. Recent explorations of non-invasive interventions in psychiatry suggest that transcranial alternating current stimulation (tACS) is a safe and potentially promising add-on to the current SZ treatment. METHODS We performed a systematic literature search for tACS studies on SZ in three databases - Embase, Pubmed and Medline. The search yielded 29 titles and abstracts, of which 8 met the criteria for inclusion: experimental use of tACS on patients with SZ. RESULTS We found 8 publications where findings from tACS were applied on participants with SZ. The most common frequencies used were theta (4.5 Hertz [Hz] and 6 Hz), alpha (10 Hz) and gamma (40 Hz). The main findings resulting from tACS delivery were: (1) decrease in auditory hallucinations; (2) decrease in negative symptoms; (3) cognitive improvement; and, (4) no change. CONCLUSIONS This scoping review provides a highlight of current protocols used in tACS studies on SZ, their main findings and limitations, and points towards a direction for new approaches. The wide variety of objectives, protocols and assessments used by researchers demonstrates the diversified nature of research currently used in this field, suggesting the need for a more thorough exploration as results continue to emerge.
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Affiliation(s)
- Adriana Farcas
- Center of Neuroscience Studies, Queen's University, Kingston, Ontario, Canada.
| | - Felicia Iftene
- Department of Psychiatry, Psychology and Center of Neuroscience, Queen's University, Kingston, Ontario, Canada
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23
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State-dependent effects of neural stimulation on brain function and cognition. Nat Rev Neurosci 2022; 23:459-475. [PMID: 35577959 DOI: 10.1038/s41583-022-00598-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2022] [Indexed: 01/02/2023]
Abstract
Invasive and non-invasive brain stimulation methods are widely used in neuroscience to establish causal relationships between distinct brain regions and the sensory, cognitive and motor functions they subserve. When combined with concurrent brain imaging, such stimulation methods can reveal patterns of neuronal activity responsible for regulating simple and complex behaviours at the level of local circuits and across widespread networks. Understanding how fluctuations in physiological states and task demands might influence the effects of brain stimulation on neural activity and behaviour is at the heart of how we use these tools to understand cognition. Here we review the concept of such 'state-dependent' changes in brain activity in response to neural stimulation, and consider examples from research on altered states of consciousness (for example, sleep and anaesthesia) and from task-based manipulations of selective attention and working memory. We relate relevant findings from non-invasive methods used in humans to those obtained from direct electrical and optogenetic stimulation of neuronal ensembles in animal models. Given the widespread use of brain stimulation as a research tool in the laboratory and as a means of augmenting or restoring brain function, consideration of the influence of changing physiological and cognitive states is crucial for increasing the reliability of these interventions.
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Jacobson N, Lithgow B, Jafari Jozani M, Moussavi Z. The Effect of Transcranial Alternating Current Stimulation With Cognitive Training on Executive Brain Function in Individuals With Dementia: Protocol for a Crossover Randomized Controlled Trial. JMIR Res Protoc 2022; 11:e37282. [PMID: 35475789 PMCID: PMC9096654 DOI: 10.2196/37282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/01/2022] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Although memory and cognitive declines are associated with normal brain aging, they may also be precursors to dementia. OBJECTIVE We aim to offer a novel approach to prevent or slow the progress of neurodegenerative dementia, or plausibly, improve the cognitive functions of individuals with dementia. METHODS We will recruit and enroll 75 participants (older than 50 years old with either mild cognitive impairment or probable early or moderate dementia) for this double-blind randomized controlled study to estimate the efficacy of active transcranial alternating current stimulation with cognitive treatment (in comparison with sham transcranial alternating current stimulation). This will be a crossover study; a cycle consists of sham or active treatment for a period of 4 weeks (5 days per week, in two 30-minute sessions with a half-hour break in between), and participants are randomized into 2 groups, with stratification by age, sex, and cognitive level (measured with the Montreal Cognitive Assessment). Outcomes will be assessed before and after each treatment cycle. The primary outcomes are changes in Wechsler Memory Scale Older Adult Battery and Alzheimer Disease Assessment Scale scores. Secondary outcomes are changes in performance on tests of frontal lobe functioning (verbal fluency), neuropsychiatric symptoms (Neuropsychiatric Inventory Questionnaire), mood changes (Montgomery-Åsberg Depression Rating Scale), and short-term recall (visual 1-back task). Exploratory outcome measures will also be assessed: static and dynamic vestibular response using electrovestibulography, neuronal changes using functional near-infrared spectroscopy, and change in spatial orientation using virtual reality navigation. RESULTS As of February 10, 2022, the study is ongoing: 7 patients have been screened, and all were deemed eligible for and enrolled in the study; 4 participants have completed baseline assessments. CONCLUSIONS We anticipate that transcranial alternating current stimulation will be a well-tolerated treatment, with no serious side effects and with considerable short- and long-term cognitive improvements. TRIAL REGISTRATION Clinicaltrials.gov NCT05203523; https://clinicaltrials.gov/show/NCT05203523. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/37282.
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Affiliation(s)
- Natasha Jacobson
- Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Brian Lithgow
- Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB, Canada
- Monash Alfred Psychiatry Research Centre, Monash University Central Clinical School, Melbourne, Australia
| | | | - Zahra Moussavi
- Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB, Canada
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Sadeghihassanabadi F, Misselhorn J, Gerloff C, Zittel-Dirks S. Optimizing the Montage for Cerebellar Transcranial Alternating Current Stimulation (tACS): a Combined Computational and Experimental Study. J Neural Eng 2022; 19. [PMID: 35421852 DOI: 10.1088/1741-2552/ac676f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 04/13/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The application of cerebellar transcranial alternating current stimulation (tACS) is limited by the absence of commonly agreed montages and also the presence of unpleasant side effects. We aimed to find the most effective cerebellar tACS montage with minimum side effects (skin sensations and phosphenes). APPROACH We first simulated cerebellar tACS with five montages (return electrode on forehead, buccinator, jaw, and neck positions, additionally focal montage with high-definition ring electrodes) to compare induced cerebellar current, then stimulated healthy participants and evaluated side effects for different montages and varying stimulation frequencies. MAIN RESULTS The simulation revealed a descending order of current density in the cerebellum from forehead to buccinator, jaw, neck and ring montage respectively. Montages inducing higher current intensity in the eyeballs during the simulation resulted in stronger and broader phosphenes during tACS sessions. Strong co-stimulation of the brainstem was observed for the neck. Skin sensations did not differ between montages or frequencies. We propose the jaw montage as an optimal choice for maximizing cerebellar stimulation while minimizing unwanted side effects. SIGNIFICANCE These findings contribute to adopting a standard cerebellar tACS protocol. The combination of computational modelling and experimental data offers improved experimental control, safety, effectiveness, and reproducibility to all brain stimulation practices.
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Affiliation(s)
- Fatemeh Sadeghihassanabadi
- Klinik und Poliklinik für Neurologie, University Medical Center Hamburg-Eppendorf Head and Neurocenter, Martinistraße 52, Hamburg, Hamburg, 20246, GERMANY
| | - Jonas Misselhorn
- Institut für Neurophysiologie und Pathophysiologie , Universitätsklinikum Hamburg-Eppendorf Zentrum für Experimentelle Medizin, Martinistraße 52, Hamburg, Hamburg, 20246, GERMANY
| | - Christian Gerloff
- Department of Neurology, University Medical Center, Universitatsklinikum Hamburg-Eppendorf, Martinistraße 52, Hamburg, Hamburg, 20246, GERMANY
| | - Simone Zittel-Dirks
- Klinik und Poliklinik für Neurologie, University Medical Center Hamburg-Eppendorf Head and Neurocenter, Martinistraße 52, Hamburg, Hamburg, 20246, GERMANY
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Nieuwhof F, Toni I, Buijink AW, van Rootselaar AF, van de Warrenburg BP, Helmich RC. Phase-locked transcranial electrical brain stimulation for tremor suppression in dystonic tremor syndromes. Clin Neurophysiol 2022; 140:239-250. [DOI: 10.1016/j.clinph.2022.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 12/19/2022]
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Directionality of the injected current targeting the P20/N20 source determines the efficacy of 140 Hz transcranial alternating current stimulation (tACS)-induced aftereffects in the somatosensory cortex. PLoS One 2022; 17:e0266107. [PMID: 35324989 PMCID: PMC8947130 DOI: 10.1371/journal.pone.0266107] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 03/14/2022] [Indexed: 11/19/2022] Open
Abstract
Interindividual anatomical differences in the human cortex can lead to suboptimal current directions and may result in response variability of transcranial electrical stimulation methods. These differences in brain anatomy require individualized electrode stimulation montages to induce an optimal current density in the targeted area of each individual subject. We aimed to explore the possible modulatory effects of 140 Hz transcranial alternating current stimulation (tACS) on the somatosensory cortex using personalized multi-electrode stimulation montages. In two randomized experiments using either tactile finger or median nerve stimulation, we measured by evoked potentials the plasticity aftereffects and oscillatory power changes after 140 Hz tACS at 1.0 mA as compared to sham stimulation (n = 17, male = 9). We found a decrease in the power of oscillatory mu-rhythms during and immediately after tactile discrimination tasks, indicating an engagement of the somatosensory system during stimulus encoding. On a group level both the oscillatory power and the evoked potential amplitudes were not modulated by tACS neither after tactile finger stimulation nor after median nerve stimulation as compared to sham stimulation. On an individual level we could however demonstrate that lower angular difference (i.e., differences between the injected current vector in the target region and the source orientation vector) is associated with significantly higher changes in both P20/N20 and N30/P30 source activities. Our findings suggest that the higher the directionality of the injected current correlates to the dipole orientation the greater the tACS-induced aftereffects are.
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Double-blind randomized N-of-1 trial of transcranial alternating current stimulation for mal de débarquement syndrome. PLoS One 2022; 17:e0263558. [PMID: 35120184 PMCID: PMC8815977 DOI: 10.1371/journal.pone.0263558] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 01/13/2022] [Indexed: 11/24/2022] Open
Abstract
Background Mal de Débarquement Syndrome (MdDS) is a medically refractory neurotological disorder characterized by persistent oscillating vertigo that follows a period of entrainment to oscillating motion such as experienced during sea or air travel. Fronto-occipital hypersynchrony may correlate with MdDS symptom severity. Materials and methods Individuals with treatment refractory MdDS lasting at least 6 months received single administrations of three fronto-occipital transcranial alternating current stimulation (tACS) protocols in an “n-of-1” double-blind randomized design: alpha frequency anti-phase, alpha-frequency in-phase, and gamma frequency control. Baseline assessments were made on Day 1. The treatment protocol that led to the most acute reduction in symptoms during a test session on Day 2 was administered for 10–12 stacked sessions given on Days 3 through 5 (20-minutes at 2-4mA). Pre to post symptom changes were assessed on Day 1 and Day 5. Participants who could clearly choose a preferred protocol on Day 2 did better on Day 5 than those who could not make a short-term determination on Day 2 and either chose a protocol based on minimized side effects or were randomized to one of the three protocols. In addition, weekly symptom assessments were made for four baseline and seven post stimulation points for the Dizziness Handicap Inventory (DHI), MdDS Balance Rating Scale (MBRS), and Hospital Anxiety and Depression Scale (HADS). Results Of 24 participants, 13 chose anti-phase, 7 chose in-phase, and 4 chose control stimulation. Compared to baseline, 10/24 completers noted ≥ 25% reduction, 5/24 ≥50% reduction, and 2/24 ≥75% reduction in oscillating vertigo intensity from Day 1 to Day 5. Stimulating at a frequency slightly higher than the individual alpha frequency (IAF) was better than stimulating at exactly the IAF, and slightly better than stimulating with a strategy of standardized stimulation at 10Hz. A one-way repeated measures ANOVA of weekly DHI, MBRS, and HADS measurements showed significant reductions immediately after treatment with improvement increasing through post-treatment week 6. Conclusion Fronto-occipital tACS may be effective in reducing the oscillating vertigo of MdDS and serve as a portable neuromodulation alternative for longer-term treatment. Stimulation frequency relative to the IAF may be important in determining the optimum treatment protocol [ClinicalTrials.gov study NCT02540616. https://clinicaltrials.gov/ct2/show/NCT02540616].
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Armstrong SR, Bland NS, Sale MV, Cunnington R. Unconscious Influences on "Free Will" Movement Initiation: Slow-wave Brain Stimulation and the Readiness Potential. J Cogn Neurosci 2022; 34:1038-1052. [PMID: 35195727 DOI: 10.1162/jocn_a_01840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
A central objective in the study of volition has been to identify how changes in neural activity relate to voluntary-"free will"-movement. The readiness potential (RP) is observed in the EEG as a slow-building signal that precedes action onset. Many consider the RP as a marker of an underlying preparatory process for initiating voluntary movement. However, the RP may emerge from ongoing slow-wave brain oscillations that influence the timing of movement initiation in a phase-dependent manner. Transcranial alternating current stimulation (tACS) enables brain oscillations to be entrained at the frequency of stimulation. We delivered tACS at a slow-wave frequency over frontocentral motor areas while participants (n = 30) performed a simple, self-paced button press task. During the active tACS condition, participants showed a tendency to initiate actions in the phase of the tACS cycle that corresponded to increased negative potentials across the frontocentral motor region. Comparisons of premovement EEG activity observed over frontocentral and central scalp electrodes showed earlier onset and increased amplitude of RPs from active stimulation compared with sham stimulation. This suggests that movement-related activity in the brain can be modulated by the delivery of weak, nonconsciously perceptible alternating currents over frontocentral motor regions. We present novel findings that support existing theories, which suggest the timing of voluntary movement is influenced by the phase of slow-changing oscillating brain states.
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30
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Al Qasem W, Abubaker M, Kvašňák E. Working Memory and Transcranial-Alternating Current Stimulation-State of the Art: Findings, Missing, and Challenges. Front Psychol 2022; 13:822545. [PMID: 35237214 PMCID: PMC8882605 DOI: 10.3389/fpsyg.2022.822545] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 01/19/2022] [Indexed: 12/06/2022] Open
Abstract
Working memory (WM) is a cognitive process that involves maintaining and manipulating information for a short period of time. WM is central to many cognitive processes and declines rapidly with age. Deficits in WM are seen in older adults and in patients with dementia, schizophrenia, major depression, mild cognitive impairment, Alzheimer's disease, etc. The frontal, parietal, and occipital cortices are significantly involved in WM processing and all brain oscillations are implicated in tackling WM tasks, particularly theta and gamma bands. The theta/gamma neural code hypothesis assumes that retained memory items are recorded via theta-nested gamma cycles. Neuronal oscillations can be manipulated by sensory, invasive- and non-invasive brain stimulations. Transcranial alternating-current stimulation (tACS) and repetitive transcranial magnetic stimulation (rTMS) are frequency-tuned non-invasive brain stimulation (NIBS) techniques that have been used to entrain endogenous oscillations in a frequency-specific manner. Compared to rTMS, tACS demonstrates superior cost, tolerability, portability, and safety profile, making it an attractive potential tool for improving cognitive performance. Although cognitive research with tACS is still in its infancy compared to rTMS, a number of studies have shown a promising WM enhancement effect, especially in the elderly and patients with cognitive deficits. This review focuses on the various methods and outcomes of tACS on WM in healthy and unhealthy human adults and highlights the established findings, unknowns, challenges, and perspectives important for translating laboratory tACS into realistic clinical settings. This will allow researchers to identify gaps in the literature and develop frequency-tuned tACS protocols with promising safety and efficacy outcomes. Therefore, research efforts in this direction should help to consider frequency-tuned tACS as a non-pharmacological tool of cognitive rehabilitation in physiological aging and patients with cognitive deficits.
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Affiliation(s)
- Wiam Al Qasem
- Department of Medical Biophysics and Medical Informatics, Third Faculty of Medicine, Charles University in Prague, Praha, Czechia
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31
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Rothwell J, Antal A, Burke D, Carlsen A, Georgiev D, Jahanshahi M, Sternad D, Valls-Solé J, Ziemann U. Central nervous system physiology. Clin Neurophysiol 2021; 132:3043-3083. [PMID: 34717225 PMCID: PMC8863401 DOI: 10.1016/j.clinph.2021.09.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/13/2021] [Accepted: 09/20/2021] [Indexed: 12/15/2022]
Abstract
This is the second chapter of the series on the use of clinical neurophysiology for the study of movement disorders. It focusses on methods that can be used to probe neural circuits in brain and spinal cord. These include use of spinal and supraspinal reflexes to probe the integrity of transmission in specific pathways; transcranial methods of brain stimulation such as transcranial magnetic stimulation and transcranial direct current stimulation, which activate or modulate (respectively) the activity of populations of central neurones; EEG methods, both in conjunction with brain stimulation or with behavioural measures that record the activity of populations of central neurones; and pure behavioural measures that allow us to build conceptual models of motor control. The methods are discussed mainly in relation to work on healthy individuals. Later chapters will focus specifically on changes caused by pathology.
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Affiliation(s)
- John Rothwell
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK,Corresponding author at: Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK, (J. Rothwell)
| | - Andrea Antal
- Department of Neurology, University Medical Center Göttingen, Germany
| | - David Burke
- Department of Neurology, Royal Prince Alfred Hospital, University of Sydney, Sydney 2050, Australia
| | - Antony Carlsen
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Dejan Georgiev
- Department of Neurology, University Medical Centre Ljubljana, Slovenia
| | - Marjan Jahanshahi
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Dagmar Sternad
- Departments of Biology, Electrical & Computer Engineering, and Physics, Northeastern University, Boston, MA 02115, USA
| | - Josep Valls-Solé
- Institut d’Investigació Biomèdica August Pi I Sunyer, Villarroel, 170, Barcelona, Spain
| | - Ulf Ziemann
- Department of Neurology and Stroke, and Hertie Institute for Clinical Brain Research, Eberhard Karls University, Tübingen, Germany
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Xu J, Wu Z, Nürnberger A, Sabel BA. Reorganization of Brain Functional Connectivity Network and Vision Restoration Following Combined tACS-tDCS Treatment After Occipital Stroke. Front Neurol 2021; 12:729703. [PMID: 34777199 PMCID: PMC8580405 DOI: 10.3389/fneur.2021.729703] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/17/2021] [Indexed: 01/01/2023] Open
Abstract
Objective: Non-invasive brain stimulation (NIBS) is already known to improve visual field functions in patients with optic nerve damage and partially restores the organization of brain functional connectivity networks (FCNs). However, because little is known if NIBS is effective also following brain damage, we now studied the correlation between visual field recovery and FCN reorganization in patients with stroke of the central visual pathway. Method: In a controlled, exploratory trial, 24 patients with hemianopia were randomly assigned to one of three brain stimulation groups: transcranial direct current stimulation (tDCS)/transcranial alternating current stimulation (tACS) (ACDC); sham tDCS/tACS (AC); sham tDCS/sham tACS (Sham), which were compared to age-matched controls (n = 24). Resting-state electroencephalogram (EEG) was collected at baseline, after 10 days stimulation and at 2 months follow-up. EEG recordings were analyzed for FCN measures using graph theory parameters, and FCN small worldness of the network and long pairwise coherence parameter alterations were then correlated with visual field performance. Result: ACDC enhanced alpha-band FCN strength in the superior occipital lobe of the lesioned hemisphere at follow-up. A negative correlation (r = −0.80) was found between the intact visual field size and characteristic path length (CPL) after ACDC with a trend of decreased alpha-band centrality of the intact middle occipital cortex. ACDC also significantly decreased delta band coherence between the lesion and the intact occipital lobe, and coherence was enhanced between occipital and temporal lobe of the intact hemisphere in the low beta band. Responders showed significantly higher strength in the low alpha band at follow-up in the intact lingual and calcarine cortex and in the superior occipital region of the lesioned hemisphere. Conclusion: While ACDC decreases delta band coherence between intact and damaged occipital brain areas indicating inhibition of low-frequency neural oscillations, ACDC increases FCN connectivity between the occipital and temporal lobe in the intact hemisphere. When taken together with the lower global clustering coefficient in responders, these findings suggest that FCN reorganization (here induced by NIBS) is adaptive in stroke. It leads to greater efficiency of neural processing, where the FCN requires fewer connections for visual processing.
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Affiliation(s)
- Jiahua Xu
- Institute of Medical Psychology, Medical Faculty, Otto-V.-Guericke University of Magdeburg, Magdeburg, Germany.,Faculty of Computer Science, Otto-V.-Guericke University of Magdeburg, Magdeburg, Germany
| | - Zheng Wu
- Institute of Medical Psychology, Medical Faculty, Otto-V.-Guericke University of Magdeburg, Magdeburg, Germany.,Faculty of Computer Science, Otto-V.-Guericke University of Magdeburg, Magdeburg, Germany
| | - Andreas Nürnberger
- Faculty of Computer Science, Otto-V.-Guericke University of Magdeburg, Magdeburg, Germany
| | - Bernhard A Sabel
- Institute of Medical Psychology, Medical Faculty, Otto-V.-Guericke University of Magdeburg, Magdeburg, Germany
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Geffen A, Bland N, Sale MV. Effects of Slow Oscillatory Transcranial Alternating Current Stimulation on Motor Cortical Excitability Assessed by Transcranial Magnetic Stimulation. Front Hum Neurosci 2021; 15:726604. [PMID: 34588969 PMCID: PMC8473706 DOI: 10.3389/fnhum.2021.726604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/24/2021] [Indexed: 11/13/2022] Open
Abstract
Converging evidence suggests that transcranial alternating current stimulation (tACS) may entrain endogenous neural oscillations to match the frequency and phase of the exogenously applied current and this entrainment may outlast the stimulation (although only for a few oscillatory cycles following the cessation of stimulation). However, observing entrainment in the electroencephalograph (EEG) during stimulation is extremely difficult due to the presence of complex tACS artifacts. The present study assessed entrainment to slow oscillatory (SO) tACS by measuring motor cortical excitability across different oscillatory phases during (i.e., online) and outlasting (i.e., offline) stimulation. 30 healthy participants received 60 trials of intermittent SO tACS (0.75 Hz; 16 s on/off interleaved) at an intensity of 2 mA peak-to-peak. Motor cortical excitability was assessed using transcranial magnetic stimulation (TMS) of the hand region of the primary motor cortex (M1HAND) to induce motor evoked potentials (MEPs) in the contralateral thumb. MEPs were acquired at four time-points within each trial – early online, late online, early offline, and late offline – as well as at the start and end of the overall stimulation period (to probe longer-lasting aftereffects of tACS). A significant increase in MEP amplitude was observed from pre- to post-tACS (paired-sample t-test; t29 = 2.64, P = 0.013, d = 0.48) and from the first to the last tACS block (t29 = −2.93, P = 0.02, d = 0.54). However, no phase-dependent modulation of excitability was observed. Therefore, although SO tACS had a facilitatory effect on motor cortical excitability that outlasted stimulation, there was no evidence supporting entrainment of endogenous oscillations as the underlying mechanism.
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Affiliation(s)
- Asher Geffen
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Nicholas Bland
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, QLD, Australia.,Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia.,School of Human Movement and Nutrition Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Martin V Sale
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, QLD, Australia.,Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia
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Coldea A, Morand S, Veniero D, Harvey M, Thut G. Parietal alpha tACS shows inconsistent effects on visuospatial attention. PLoS One 2021; 16:e0255424. [PMID: 34351972 PMCID: PMC8341497 DOI: 10.1371/journal.pone.0255424] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/15/2021] [Indexed: 11/19/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) is a popular technique that has been used for manipulating brain oscillations and inferring causality regarding the brain-behaviour relationship. Although it is a promising tool, the variability of tACS results has raised questions regarding the robustness and reproducibility of its effects. Building on recent research using tACS to modulate visuospatial attention, we here attempted to replicate findings of lateralized parietal tACS at alpha frequency to induce a change in attention bias away from the contra- towards the ipsilateral visual hemifield. 40 healthy participants underwent tACS in two separate sessions where either 10 Hz tACS or sham was applied via a high-density montage over the left parietal cortex at 1.5 mA for 20 min, while performance was assessed in an endogenous attention task. Task and tACS parameters were chosen to match those of previous studies reporting positive effects. Unlike these studies, we did not observe lateralized parietal alpha tACS to affect attention deployment or visual processing across the hemifields as compared to sham. Likewise, additional resting electroencephalography immediately offline to tACS did not reveal any notable effects on individual alpha power or frequency. Our study emphasizes the need for more replication studies and systematic investigations of the factors that drive tACS effects.
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Affiliation(s)
- Andra Coldea
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
| | - Stephanie Morand
- School of Life Sciences, MVLS College, University of Glasgow, Glasgow, United Kingdom
| | - Domenica Veniero
- School of Psychology, University of Nottingham, Nottingham, United Kingdom
| | - Monika Harvey
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
| | - Gregor Thut
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
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35
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Lorentz force induced shear waves for magnetic resonance elastography applications. Sci Rep 2021; 11:12785. [PMID: 34140568 PMCID: PMC8211670 DOI: 10.1038/s41598-021-91895-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/02/2021] [Indexed: 11/08/2022] Open
Abstract
Quantitative mechanical properties of biological tissues can be mapped using the shear wave elastography technique. This technology has demonstrated a great potential in various organs but shows a limit due to wave attenuation in biological tissues. An option to overcome the inherent loss in shear wave magnitude along the propagation pathway may be to stimulate tissues closer to regions of interest using alternative motion generation techniques. The present study investigated the feasibility of generating shear waves by applying a Lorentz force directly to tissue mimicking samples for magnetic resonance elastography applications. This was done by combining an electrical current with the strong magnetic field of a clinical MRI scanner. The Local Frequency Estimation method was used to assess the real value of the shear modulus of tested phantoms from Lorentz force induced motion. Finite elements modeling of reported experiments showed a consistent behavior but featured wavelengths larger than measured ones. Results suggest the feasibility of a magnetic resonance elastography technique based on the Lorentz force to produce an shear wave source.
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Beliaeva V, Savvateev I, Zerbi V, Polania R. Toward integrative approaches to study the causal role of neural oscillations via transcranial electrical stimulation. Nat Commun 2021; 12:2243. [PMID: 33854049 PMCID: PMC8047004 DOI: 10.1038/s41467-021-22468-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 03/15/2021] [Indexed: 11/12/2022] Open
Abstract
Diverse transcranial electrical stimulation (tES) techniques have recently been developed to elucidate the role of neural oscillations, but critically, it remains questionable whether neural entrainment genuinely occurs and is causally related to the resulting behavior. Here, we provide a perspective on an emerging integrative research program across systems, species, theoretical and experimental frameworks to elucidate the potential of tES to induce neural entrainment. We argue that such an integrative agenda is a requirement to establish tES as a tool to test the causal role of neural oscillations and highlight critical issues that should be considered when adopting a translational approach.
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Affiliation(s)
- Valeriia Beliaeva
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, Switzerland, Zurich, Switzerland.
| | - Iurii Savvateev
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, Switzerland, Zurich, Switzerland
| | - Valerio Zerbi
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, Switzerland, Zurich, Switzerland
| | - Rafael Polania
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, Switzerland, Zurich, Switzerland.
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Prolonged deficit of low gamma oscillations in the peri-infarct cortex of mice after stroke. Exp Neurol 2021; 341:113696. [PMID: 33727098 DOI: 10.1016/j.expneurol.2021.113696] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 03/04/2021] [Accepted: 03/11/2021] [Indexed: 02/06/2023]
Abstract
Days and weeks after an ischemic stroke, the peri-infarct area adjacent to the necrotic tissue exhibits very intense synaptic reorganization aimed at regaining lost functions. In order to enhance functional recovery, it is important to understand the mechanisms supporting neural repair and neuroplasticity in the cortex surrounding the lesion. Brain oscillations of the local field potential (LFP) are rhythmic fluctuations of neuronal excitability that synchronize neuronal activity to organize information processing and plasticity. Although the oscillatory activity of the brain has been probed after stroke in both animals and humans using electroencephalography (EEG), the latter is ineffective to precisely map the oscillatory changes in the peri-infarct zone where synaptic plasticity potential is high. Here, we worked on the hypothesis that the brain oscillatory system is altered in the surviving peri-infarct cortex, which may slow down the functional repair and reduce the recovery. In order to document the relevance of this hypothesis, oscillatory power was measured at various distances from the necrotic core at 7 and 21 days after a permanent cortical ischemia induced in mice. Delta and theta oscillations remained at a normal power in the peri-infarct cortex, in contrast to low gamma oscillations that displayed a gradual decrease, when approaching the border of the lesion. A broadband increase of power was also observed in the homotopic contralateral sites. Thus, the proximal peri-infarct cortex could become a target of therapeutic interventions applied to correct the oscillatory regimen in order to boost post-stroke functional recovery.
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Moussavi Z, Kimura K, Kehler L, de Oliveira Francisco C, Lithgow B. A Novel Program to Improve Cognitive Function in Individuals With Dementia Using Transcranial Alternating Current Stimulation (tACS) and Tutored Cognitive Exercises. FRONTIERS IN AGING 2021; 2:632545. [PMID: 35822057 PMCID: PMC9261296 DOI: 10.3389/fragi.2021.632545] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/08/2021] [Indexed: 12/20/2022]
Abstract
The effects of cognitive exercises on the healthy aging population is controversial. Transcranial alternating current stimulation (tACS) is considered a promising tool for modulating brain oscillation. Research is lacking on its long-lasting cognitive/therapeutic effect. This is the first pilot study to explore the effect of a regimen of cognitive exercises with and without tACS on older adults with dementia. The study groups were 28 individuals (age 56–83 years) enrolled into two groups: Exr Group, who received cognitive exercises only and the Exr + tACS Group who received tACS at 40 Hz simultaneously with cognitive exercises for a period of 4 consecutive weeks, 5 days/week, two 30 min-sessions/day; all the training sessions were tutored. The cognitive exercises were applied using the MindTriggers app. They were assessed at pre and post intervention and also one month after the end of trial (follow-up) with an independent assessment (WMS-IV) as the primary outcome measure. The results show significant cognitive improvement at post-intervention in both groups, while the Exr + tACS protocol lead to superior cognitive improvement at follow-up session. The most important outcomes of this study are: 1) The tutored repeated practice of the MindTriggers app exercises does significantly improve the cognitive functions of older adults with dementia and that that improvement lasts for at least one month after the end of the intervention, and 2) The application of tACS increases the positive effects of cognitive exercises with the positive effect lasting an even longer period of time than exercises alone; in other words we speculate that it may lead to long-term potentiation.
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Affiliation(s)
- Zahra Moussavi
- University of Manitoba, Biomedical Engineering, Winnipeg, MB, Canada
| | - Kazushige Kimura
- University of Manitoba, Biomedical Engineering, Winnipeg, MB, Canada
| | - Lonnie Kehler
- University of Manitoba, Biomedical Engineering, Winnipeg, MB, Canada
| | | | - Brian Lithgow
- University of Manitoba, Biomedical Engineering, Winnipeg, MB, Canada
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Bland NS. Is two decades of tDCS work wrong? Commentary on Ahn and Frohlich. Brain Stimul 2021; 14:438-439. [PMID: 33647478 DOI: 10.1016/j.brs.2021.02.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 02/21/2021] [Indexed: 01/27/2023] Open
Affiliation(s)
- Nicholas S Bland
- School of Health and Rehabilitation Sciences, The University of Queensland, Australia.
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40
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Dantas AM, Sack AT, Bruggen E, Jiao P, Schuhmann T. Reduced risk-taking behavior during frontal oscillatory theta band neurostimulation. Brain Res 2021; 1759:147365. [PMID: 33582119 DOI: 10.1016/j.brainres.2021.147365] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 02/04/2021] [Accepted: 02/04/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND Most of our decisions involve a certain degree of risk regarding the outcomes of our choices. People vary in the way they make decisions, resulting in different levels of risk-taking behavior. These differences have been linked to prefrontal theta band activity. However, a direct functional relationship between prefrontal theta band activity and risk-taking has not yet been demonstrated. OBJECTIVE We used noninvasive brain stimulation to test the functional relevance of prefrontal oscillatory theta activity for the regulatory control of risk-taking behavior. METHODS In a within-subject experiment, 31 healthy participants received theta (6.5 Hertz [Hz]), gamma (40 Hz), and sham transcranial alternating current stimulation (tACS) over the left prefrontal cortex (lPFC). During stimulation, participants completed a task assessing their risk-taking behavior as well as response times and sensitivity to value and outcome probabilities. Electroencephalography (EEG) was recorded before and immediately after stimulation to investigate possible long-lasting stimulation effects. RESULTS Theta band, but not gamma band or sham, tACS led to a significant reduction in risk-taking behavior, indicating a frequency-specific effect of prefrontal brain stimulation on the modulation of risk-taking behavior. Moreover, theta band stimulation led to increased response times and decreased sensitivity to reward values. EEG data analyses did not show an offline increase in power in the stimulated frequencies after the stimulation protocol. CONCLUSION These findings provide direct empirical evidence for the effects of prefrontal theta band stimulation on behavioral risk-taking regulation.
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Affiliation(s)
- Aline M Dantas
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands; Maastricht Brain Imaging Centre, Maastricht University, Maastricht, The Netherlands; Department of Marketing and Supply Chain Management, School of Business and Economics, Maastricht University, Maastricht, The Netherlands.
| | - Alexander T Sack
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands; Maastricht Brain Imaging Centre, Maastricht University, Maastricht, The Netherlands; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Brain + Nerve Centre, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
| | - Elisabeth Bruggen
- Department of Marketing and Supply Chain Management, School of Business and Economics, Maastricht University, Maastricht, The Netherlands
| | - Peiran Jiao
- Department of Finance, School of Business and Economics, Maastricht University, Maastricht, The Netherlands
| | - Teresa Schuhmann
- Section Brain Stimulation and Cognition, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands; Maastricht Brain Imaging Centre, Maastricht University, Maastricht, The Netherlands
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41
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Elyamany O, Leicht G, Herrmann CS, Mulert C. Transcranial alternating current stimulation (tACS): from basic mechanisms towards first applications in psychiatry. Eur Arch Psychiatry Clin Neurosci 2021; 271:135-156. [PMID: 33211157 PMCID: PMC7867505 DOI: 10.1007/s00406-020-01209-9] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 10/27/2020] [Indexed: 12/11/2022]
Abstract
Transcranial alternating current stimulation (tACS) is a unique form of non-invasive brain stimulation. Sinusoidal alternating electric currents are delivered to the scalp to affect mostly cortical neurons. tACS is supposed to modulate brain function and, in turn, cognitive processes by entraining brain oscillations and inducing long-term synaptic plasticity. Therefore, tACS has been investigated in cognitive neuroscience, but only recently, it has been also introduced in psychiatric clinical trials. This review describes current concepts and first findings of applying tACS as a potential therapeutic tool in the field of psychiatry. The current understanding of its mechanisms of action is explained, bridging cellular neuronal activity and the brain network mechanism. Revisiting the relevance of altered brain oscillations found in six major psychiatric disorders, putative targets for the management of mental disorders using tACS are discussed. A systematic literature search on PubMed was conducted to report findings of the clinical studies applying tACS in patients with psychiatric conditions. In conclusion, the initial results may support the feasibility of tACS in clinical psychiatric populations without serious adverse events. Moreover, these results showed the ability of tACS to reset disturbed brain oscillations, and thus to improve behavioural outcomes. In addition to its potential therapeutic role, the reactivity of the brain circuits to tACS could serve as a possible tool to determine the diagnosis, classification or prognosis of psychiatric disorders. Future double-blind randomised controlled trials are necessary to answer currently unresolved questions. They may aim to detect response predictors and control for various confounding factors.
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Affiliation(s)
- Osama Elyamany
- Centre of Psychiatry, Justus-Liebig University, Klinikstrasse 36, 35392, Giessen, Hessen, Germany
- Centre for Mind, Brain and Behaviour (CMBB), University of Marburg and Justus-Liebig University Giessen, Marburg, Germany
| | - Gregor Leicht
- Department of Psychiatry and Psychotherapy, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph S Herrmann
- Experimental Psychology Lab, Centre for Excellence "Hearing4all," European Medical School, University of Oldenburg, Oldenburg, Lower Saxony, Germany
- Research Centre Neurosensory Science, University of Oldenburg, Oldenburg, Lower Saxony, Germany
| | - Christoph Mulert
- Centre of Psychiatry, Justus-Liebig University, Klinikstrasse 36, 35392, Giessen, Hessen, Germany.
- Centre for Mind, Brain and Behaviour (CMBB), University of Marburg and Justus-Liebig University Giessen, Marburg, Germany.
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42
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Lajoie K, Marigold DS, Valdés BA, Menon C. The potential of noisy galvanic vestibular stimulation for optimizing and assisting human performance. Neuropsychologia 2021; 152:107751. [PMID: 33434573 DOI: 10.1016/j.neuropsychologia.2021.107751] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 12/17/2022]
Abstract
Noisy galvanic vestibular stimulation (nGVS) is an emerging non-invasive brain stimulation technique. It involves applying alternating currents of different frequencies and amplitudes presented in a random, or noisy, manner through electrodes on the mastoid bones behind the ears. Because it directly activates vestibular hair cells and afferents and has an indirect effect on a variety of brain regions, it has the potential to impact many different functions. The objective of this review is twofold: (1) to review how nGVS affects motor, sensory, and cognitive performance in healthy adults; and (2) to discuss potential clinical applications of nGVS. First, we introduce the technique. We then describe the regions receiving and processing vestibular information. Next, we discuss the effects of nGVS on motor, sensory, and cognitive function in healthy adults. Subsequently, we outline its potential clinical applications. Finally, we highlight other electrical stimulation technologies and discuss why nGVS offers an alternative or complementary approach. Overall, nGVS appears promising for optimizing human performance and as an assistive technology, though further research is required.
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Affiliation(s)
- Kim Lajoie
- Menrva Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada
| | - Daniel S Marigold
- Sensorimotor Neuroscience Lab, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
| | - Bulmaro A Valdés
- Menrva Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada
| | - Carlo Menon
- Menrva Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada.
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43
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The Modulation of Cognitive Performance with Transcranial Alternating Current Stimulation: A Systematic Review of Frequency-Specific Effects. Brain Sci 2020; 10:brainsci10120932. [PMID: 33276533 PMCID: PMC7761592 DOI: 10.3390/brainsci10120932] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/20/2020] [Accepted: 11/29/2020] [Indexed: 12/21/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that allows the manipulation of intrinsic brain oscillations. Numerous studies have applied tACS in the laboratory to enhance cognitive performance. With this systematic review, we aim to provide an overview of frequency-specific tACS effects on a range of cognitive functions in healthy adults. This may help to transfer stimulation protocols to real-world applications. We conducted a systematic literature search on PubMed and Cochrane databases and considered tACS studies in healthy adults (age > 18 years) that focused on cognitive performance. The search yielded n = 109 studies, of which n = 57 met the inclusion criteria. The results indicate that theta-tACS was beneficial for several cognitive functions, including working memory, executive functions, and declarative memory. Gamma-tACS enhanced performance in both auditory and visual perception but it did not change performance in tasks of executive functions. For attention, the results were less consistent but point to an improvement in performance with alpha- or gamma-tACS. We discuss these findings and point to important considerations that would precede a transfer to real-world applications.
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44
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Castellano M, Ibañez-Soria D, Kroupi E, Acedo J, Campolo M, Soria-Frisch A, Valls-Sole J, Verma A, Ruffini G. Intermittent tACS during a visual task impacts neural oscillations and LZW complexity. Exp Brain Res 2020; 238:1411-1422. [PMID: 32367144 DOI: 10.1007/s00221-020-05820-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 04/21/2020] [Indexed: 11/30/2022]
Abstract
Little is known about how transcranial alternating current stimulation (tACS) interacts with brain activity. Here, we investigate the effects of tACS using an intermittent tACS-EEG protocol and use, in addition to classical metrics, Lempel-Ziv-Welch complexity (LZW) to characterize the interactions between task, endogenous and exogenous oscillations. In a cross-over study, EEG was recorded from thirty participants engaged in a change-of-speed detection task while receiving multichannel tACS over the visual cortex at 10 Hz, 70 Hz and a control condition. In each session, tACS was applied intermittently during 5 s events interleaved with EEG recordings over multiple trials. We found that, with respect to control, stimulation at 10 Hz ([Formula: see text]) enhanced both [Formula: see text] and [Formula: see text] power, [Formula: see text]-LZW complexity and [Formula: see text] but not [Formula: see text] phase locking value with respect to tACS onset ([Formula: see text]-PLV, [Formula: see text]-PLV), and increased reaction time (RT). [Formula: see text] increased RT with little impact on other metrics. As trials associated with larger [Formula: see text]-power (and lower [Formula: see text]-LZW) predicted shorter RT, we argue that [Formula: see text] produces a disruption of functionally relevant fast oscillations through an increase in [Formula: see text]-band power, slowing behavioural responses and increasing the complexity of gamma oscillations. Our study highlights the complex interaction between tACS and endogenous brain dynamics, and suggests the use of algorithmic complexity inspired metrics to characterize cortical dynamics in a behaviorally relevant timescale.
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Affiliation(s)
- Marta Castellano
- Starlab Barcelona SL, Av. del Tibidabo 47 bis, 08035, Barcelona, Spain
| | | | - Eleni Kroupi
- Starlab Barcelona SL, Av. del Tibidabo 47 bis, 08035, Barcelona, Spain
| | - Javier Acedo
- Neuroelectrics SLU, Av. del Tibidabo 47 bis, 08035, Barcelona, Spain
| | - Michela Campolo
- EMG Unit, Neurology Department, Hospital Clinic and IDIBAPS (Institut d'Inveatigació Agustí Pi i Sunyer), Facultat de Medicina, University of Barcelona, Barcelona, Spain
| | | | - Josep Valls-Sole
- EMG Unit, Neurology Department, Hospital Clinic and IDIBAPS (Institut d'Inveatigació Agustí Pi i Sunyer), Facultat de Medicina, University of Barcelona, Barcelona, Spain
| | - Ajay Verma
- Biogen Inc., 225 Binney St, Cambridge, MA, USA
| | - Giulio Ruffini
- Neuroelectrics Corp., 2 10 Broadway, Suite 201, Cambridge, MA, 02139, USA.
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45
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Bland NS, Mattingley JB, Sale MV. Gamma coherence mediates interhemispheric integration during multiple object tracking. J Neurophysiol 2020; 123:1630-1644. [PMID: 32186427 DOI: 10.1152/jn.00755.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Our ability to track the paths of multiple visual objects moving between the hemifields requires effective integration of information between the two cerebral hemispheres. Coherent neural oscillations in the gamma band (35-70 Hz) are hypothesized to drive this information transfer. Here we manipulated the need for interhemispheric integration using a novel multiple object tracking (MOT) task in which stimuli either moved between the two visual hemifields, requiring interhemispheric integration, or moved within separate visual hemifields. We used electroencephalography (EEG) to measure interhemispheric coherence during the task. Human observers (21 women; 20 men) were poorer at tracking objects between versus within hemifields, reflecting a cost of interhemispheric integration. Critically, gamma coherence was greater in trials requiring interhemispheric integration, particularly between sensors over parieto-occipital areas. In approximately half of the participants, the observed cost of integration was associated with a failure of the cerebral hemispheres to become coherent in the gamma band. Moreover, individual differences in this integration cost correlated with endogenous gamma coherence at these same sensors, although with generally opposing relationships for the real and imaginary part of coherence. The real part (capturing synchronization with a near-zero phase lag) benefited between-hemifield tracking; imaginary coherence was detrimental. Finally, instantaneous phase coherence over the tracking period uniquely predicted between-hemifield tracking performance, suggesting that effective integration benefits from sustained interhemispheric synchronization. Our results show that gamma coherence mediates interhemispheric integration during MOT and add to a growing body of work demonstrating that coherence drives communication across cortically distributed neural networks.NEW & NOTEWORTHY Using a multiple object tracking paradigm, we were able to manipulate the need for interhemispheric integration on a per-trial basis, while also having an objective measure of integration efficacy (i.e., tracking performance). We show that tracking performance reflects a cost of integration, which correlates with individual differences in interhemispheric EEG coherence. Gamma coherence appears to uniquely benefit between-hemifield tracking, predicting performance both across participants and across trials.
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Affiliation(s)
- Nicholas S Bland
- School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Queensland, Australia.,Queensland Brain Institute, University of Queensland, Brisbane, Queensland, Australia
| | - Jason B Mattingley
- Queensland Brain Institute, University of Queensland, Brisbane, Queensland, Australia.,School of Psychology, University of Queensland, Brisbane, Queensland, Australia
| | - Martin V Sale
- School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Queensland, Australia.,Queensland Brain Institute, University of Queensland, Brisbane, Queensland, Australia
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